High Power DC Motor Speed and Direction Control using RC Transmitter – Arduino Compatible

The project presented here is a low-cost solution to control the speed and direction of a high-power brushed DC motor using RC (Radio Remote Control) transmitter. This is an Arduino-compatible board, consisting of an Atmega328 chip, 2 x Relay for motor direction control, MOSFET for speed control using PWM input, Tactile switch, Slide switch, and Connector for RC Receiver interface. Traditional DC motor controllers are based on solid-state circuitry known as H-Bridge. Here the H-bridge configuration is created using 2x high-power Relays which can handle high voltage as well as high current. Additionally, MOSFET Q3 is used to control the speed of the motor by applying a PWM signal. This MOSFET can be removed in case of only direction control is required. In this case short the Drain and source pin of MOSFET. The project requires 3 control input signals 2 x CCW/CW direction control, and 1x PWM input. All inputs are optically isolated to prevent noise and high voltage going into logic circuitry. A large size of heatsink is a must for MOSFET.

Note: This board will work with any standard RC remote. In this project, we tested it with HOTRC DS-600 6CH 2.4GHz Radio System. Standard RC radio outputs is 50Hz – 1mS(1000uS) to 2mS(2000uS)

Arduino Code and Programming

A new ATmega328 chip requires a bootloader. Refer to the connection diagram for the Arduino boot-loader and Arduino programming. The Arduino example code is available as a download. The user will able to control the speed and direction of the brushed DC motor using RC remote Joystick. Connector U4 is provided to connect the RC receiver. ATMEGA328 chip reads the RC signal and generates 2 x CW/CCW TTL signals for motor direction control and one PWM signal. Two direction control signals control the Relay RE1 and RE2, contacts of relay configured in such a way where bidirectional output is provided to the motor, MOSFET drives the PWM signal for motor speed control. All three signals have optocouplers U2, U5, and U6 between motor control circuitry and ATMEGA328 chip which provides noise immunity and high voltage/current going to the digital circuitry.

Arduino Code Credits: modified code, original author Tech at Home Channel

More Info, Boot-Loader, and Arduino Programming: https://docs.arduino.cc/built-in-examples/arduino-isp/ArduinoToBreadboard

 

Features

  • Power Supply for Relay and MOSFET 12V to 15V DC @ 100mA
  • Power Supply Motor 12V to 90V DC (Maximum 100V DC)
  • Motor Load 20Amps (Maximum 30Amps)
  • Optocoupler Between Micro-Controller U1 and 2X Relays and MOSFET for optical isolation
  • 2 x Inputs for Direction Control and Brake
  • One PWM Signal to Control the speed of Motor 0 to 100 % Duty Cycle
  • PWM Frequency up to 20Khz
  • 2x LEDs for direction indication
  • PCB Dimensions 97 x 93.82mm
  • 4 x 4mm Mounting Holes

Arduino Pin

  • Arduino Digital Pin D3 and D4 = Relay Control, DC Motor Direction Control, D3 High – D4 Low = CCW, D3 Low – D4 High = CW
  • Arduino Digital Pin D5 = MOSFET Gate Driver (PWM for Motor Speed Control) – Duty Cycle (0 to 100%) Frequency up to 20Khz
Note: The project has been designed for multi-purpose motor applications. For the RC receiver interface use the U4 connector, the user may not install the following components SW1, SW2, R16, R17, SW4, SW3, and PR1 as they are not required.

Read below for the power supply requirements. The project works well with 2 power inputs. One for the MOSFET Gate Driver/Logic supply and 2nd for the motor supply. Advisable to use 3 power inputs for complete isolation between the motor output power driver and the logic circuit.

Power Supply: The project requires 3 power inputs for complete isolation between the microcontroller and motor output power driver.

  • 5V Logic supply (Do not solder U1 LM7805 and R15) for full isolation between Micro-Controller U3 and motor output power 2 X Relay and MOSFET Q3, Use Pin 4 and Pin 5 of CN4 for 5V Power Input
  • 12V to 15V DC supply for MOSFET gate driver
  • Motor Power Supply 12V to 90V DC

The project also can work well with only 2 power inputs

  • 12V to 15V DC Gate Driver (Solder U1 LM7805 and Resistor R15) for Dual power input.
  • Motor Supply 12V to 90V

Single Power Supply for 12V to 15V Motor

  • The project can work with a single supply for a lower voltage (12-15V) motor, Install U1 LM7805, R15 Resistor.
  • Tie GND-Pin2 + GD-Pin2 and +12V-Pin1 + DC-L Pin 1 of the CN1 and CN2 and apply 12V to 15V

Arduino-compatible hardware consists following important components which can be used for various applications as per user requirements. 

  • ATMEGA328 Microcontroller
  • MOSFET to control the Speed of the motor with the help of PWM (Arduino Digital Pin D5)
  • 2 x Relay for Motor Direction Control (Arduino Digital Pin D3 and D4)
  • 3 Pin Header to Connect Radio Remote Receiver or Analog Input (Arduino A1) – Connector U4
  • Trimmer Potentiometer for Analog Input (Arduino A0) – Don’t Install for this project
  • CN4: Arduino Programming and Boot-Loader Connector
  • SW1, SW2 = Tactile Switch (Optional) Control the Relay 1 and Relay 2 Directly – Don’t Install for this project
  • SW3: Slider Switch for Direct Direction Control – Don’t Install for this project
  • SW4: Tactile Switch Arduino Digital Pin D11

Connections and Other Details

  • CN1: Pin 1 = 12V DC for MOSFET Gate Driver, Pin 2 = GND
  • CN2: Pin 1 = +Motor Power Supply 12V to 90V DC, Pin 2 = GND
  • CN3: Pin 1 = Motor, Pin 2 = Motor
  • CN4: Programming Connector Pin 1 = TX, Pin 2 = RX, Pin 3 = Reset, Pin 4 = GND, Pin 5 = VCC, Pin 6 = D11, Pin 7 = D12, Pin 8 = D13
  • D2, D4 LED = Motor Direction LED
  • SW1, SW2: Optional Direction Switch
  • SW3: Optional Direction Switch
  • SW4: Optional Switch Connected to Arduino D11
  • U4: RC Receiver or Analog In (Arduino Analog A1)
  • PR1: Potentiometer Connected to Arduino Analog A0

Schematic

Parts List

NOQNTYREFDESCMANUFACTURERSUPPLIERSUPPLIER'S PART NO
11CN12 PIN SCREW TERMINAL PITCH 5.08MMPHOENIXDIGIKEY277-1247-ND
21CN22 PIN BARRIER BLOCK PITCH 9.53MMTE CONNECTIVITYDIGIKEY
31CN32 PIN BARRIER BLOCK PITCH 9.53MMTE CONNECTIVITYDIGIKEY
41CN48 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5321-ND
51C1220uF/25VRUBYCONDIGIKEY1189-3720-3-ND
63C2,C4,C50.1uF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
71C310uF/25V CERAMIC SMD SIZE 1206YAGEO/MURATADIGIKEY
84PR1,SW3,C6,C9DO NOT INSTALL
91C70.1uF/100VVISHAYDIGIKEYBFC2373FF104MD-ND
101C8470uF/100VNICHICONDIGIKEY493-1683-ND
112C10,C1122PF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
122D1,D3SM4007SMC DIODEDIGIKEY1655-1N4007FLCT-ND
132D2,D4LED 3MM RED OR RED + GREENAMERICAN OCTODIGIKEY2460-L314HD-ND
142Q1,Q2MPSA13ON SEMIDIGIKEY2156-MPSA13RA-ND
151Q3FDH3632ON SEMIDIGIKEYFDH3632FS-ND
162RE1,RE212V RELAY/30ACIT RELAY AND SWITCHDIGIKEY2449-L115F11CM12VDCS.9-ND
172R1,R71K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
181R210K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
194R3,R8,R16,R17470E 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
204R4,R5,R9,R102K2 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
211R610E 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
221R111M 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
232R12,R14220E 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
241R132.2E 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
251R150E SMD SIZE 0805YAGEO/MURATADIGIKEY
263SW1,SW2,SW44 PIN TACCTILE SWITCHNKK SWITCHDIGIKEYHP0215AFKP2-ND
271U1LM78M05 DPAKON SEMIDIGIKEYMC78M15ABDTRKGOSCT-ND
282U2,U5PC817 4 PIN THTAMERICAN BRIGHTDIGIKEYBPC-817(BBIN)-ND
291U3ATMEGA328TQPF-32MICROCHIPDIGIKEYATMEGA328PB-AURCT-ND
301U43 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5316-ND
311U6TLP350/TLP250 8 PIN DIPTOSHIBA SEMIDIGIKEYTLP350H(F)-ND
321X116MhzECS INCDIGIKEYX1103-ND

Connections

Gerber View

Code

//This is modified code, orignal code from YouTube|Tech at Home

int in1 = 3;
int in2 = 4;
int enable1 = 5;  // pin with ~ symbol

int channel_2 = A1;  // pin with ~ symbol

void setup() 
{
  pinMode(channel_2, INPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(enable1, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  
  int pwm = 0;
  int value = pulseIn(channel_2, HIGH, 25000);
  
  if(value==0)
  {
      digitalWrite(in1, LOW);
      digitalWrite(in2, LOW);
      analogWrite(enable1, 0);
  }
  
  else if(value > 1530)
  {
      pwm = map(value, 1530, 1930, 0, 255); 
      digitalWrite(in1, LOW);
      digitalWrite(in2, HIGH);
      analogWrite(enable1, pwm);
  }
  
  else if(value < 1460)
  {
      pwm = map(value, 1460, 1090, 0, 255); 
      digitalWrite(in1, HIGH);
      digitalWrite(in2, LOW);
      analogWrite(enable1, pwm);
  }
  
  else
  {
      digitalWrite(in1, LOW);
      digitalWrite(in2, LOW);
      analogWrite(enable1, 0);
  }
  
  delay(10);
}

 

Photos

 

Video

TLP350 Datasheet

Signal Conditioning Module for Magnetic Rotary Encoder with Clock and Up/Down Direction Signal Output

This is a highly sensitive, temperature-stable magnetic sensing module ideal for use in ring magnet-based, speed, and direction systems located in harsh automotive and industrial environments. The module is a complete solution to make a magnet-based rotary encoder, which provides clock and up/down direction signal output. The circuit consists of A1230 and LS7184 chips. A1230 is an ultra-sensitive dual-channel quadrature hall-effect bipolar switch, and LS7184 is a quadrature clock converter. A magnetic rotary encoder consists of 2 main components, a Magnetic disc, and a signal conditioner. The disc is magnetized with a number of poles around its circumference.  The A1230 quadrature sensor detects the change in a magnetic field when the disc rotates and converts this information to two-channel rectangular pulses. Further, this quadrature signal is converted to a clock and up/down direction signal using the LS7184 chip. The resolution of the rotary encoder is determined by the number of magnetic poles around the disk and the output clock can be multiplied by factors of x1, x2, and x4 by changing the IC mode using jumper J1, thus this helps in increasing the output resolution.

Mode Selection Jumper J1

  • Mode is a 3-state input to select resolution x1, x2, and x4. The input quadrature clock rate is multiplied by factors of 1,2 and 4 in x1, x2, and x4 modes respectively, thus producing a high-resolution output.

RBIAS Resistor 6 (Range 2K Ohm to 10M Ohms) – Refer to Figure

  • The value of this resistor is responsible for the output clock pulse width. Alter the value to change the output pulse width. Please Refer to the datasheet for more info.

Features

  • Supply 5V DC
  • Clock, UP/DOWN Direction Output
  • 1 mm Hall element spacing
  • Clock Can be Multiplied by Factors of x1, x2, and x4
  • On Board Jumper for Clock Multiple Factor Setting for Higher Output Resolution
  • 2 x 2.5 mm Mounting Holes
  • PCB Dimensions 32.54 x 16.99 mm

Connections and Other Details

  • CN1: Pin 1 = VCC 5V DC, Pin 2 = GND, Pin 3 = Clock Output, Pin 4 = Up/Down Direction Output
  • Jumper J1: J1 Floating/Open = X4 , VCC = X2 , GND = X1 Factors Selection
  • D1: Power LED

How do magnetic encoders work?

The A1230 is a dual-channel, bipolar switch with two Hall-effect sensing elements, each providing a separate digital output for speed and direction signal processing capability. The Hall elements are photolithographically aligned to better than 1 μm. Maintaining accurate mechanical location between the two active Hall elements eliminates the major manufacturing hurdle encountered in fine-pitch detection applications. The A1230 is a highly sensitive, temperature-stable magnetic sensing device ideal for use in ring magnet-based, speed and direction systems located in harsh automotive and industrial environments. For more details please visit: https://www.motioncontroltips.com/faq-how-do-magnetic-encoders-work/

Schematic

Parts List

NO.QNTY.REF.DESCMANUFACTURERSUPPLIERSUPPLIER PART NO
11CN14 PIN MALE HEADER PITCH 2.54MMWURTH732-5317-ND
21C110uF/16V CERAMIC SMD SIZE 1210MURATA/YAGEO
31C20.1uF/50V CERAMIC SMD SIZE 0805MURATA/YAGEO
42C3,C410KPF/50V CERAMIC SMD SIZE 0805MURATA/YAGEO
51D1RED LED SMD SIZE 0805OSRAM475-1278-1-ND
61J1JUMPER- 2PIN MALE HEADER PITCH 2.54MMWURTH732-5315-ND
72R1,R4100E 5% SMD SIZE 0805MURATA/YAGEO
82R2,R310K 5% SMD SIZE 0805MURATA/YAGEO
91R51K 5% SMD SIZE 0805MURATA/YAGEO
101R68.2M 5% SMD SIZE 0805MURATA/YAGEO
111U1A1230LLTR-T SOIC8ALLEGRO620-1348-1-ND
121U2LS7184 SOIC8lsicsi.com
131J1SHUNT - JUMPERSULLINS CONNECTS9001-ND

Connections

A1230 Block Diagram

LS7184 Block Diagram

 

Magnetics Placement

.

Output Voltage

Gerber View

Photos

Video

A1230 Datasheet

3D Effect Audio Processor

The project presented here is a 3D sound processor, that regenerates 3D sound to stereo speakers. The board is able to regenerate 3D sound from a stereo audio input. It features of wide operating voltage range, wide dynamic range, and low output noise and is suitable for any audio application. This tiny module can add 3D sound effects to your next project. Basically, this mini low-cost module converts a stereo audio signal into 3D effect audio and it is based on PT2387 chip. The chip features a specially designed PTC HRTFs filter and with its space-enhanced circuit, it provides excellent audio quality and performance. The module provides excellent 3D effect audio output from a stereo audio source and a built-in LED display when the 3D sound effect is active. A tactile switch is provided to activate the 3D sound effect.

Features

  • Operating Voltage 5V to 9V DC
  • THD= N<0.01%, S/N>95dB
  • On Board Power LED
  • Standard Audio Signal Input and Output
  • On Board 3D function LED
  • 5MM Stereo Female socket for Audio Input and Output
  • On Board Tactile Switch for 3D Sound ON/OFF
  • PCB Dimensions 55.88 x 26.67 mm
  • 4 x 2.5 mm Mounting Holes

Connections and Other Details

  • CN1: Pin 1,2 = VCC 5V TO 9V, Pin 3.4 = GND
  • CN2: Stereo EP 3.5MM Female Connector, Stereo Audio Signal Input
  • CN3: Optional Audio input
  • CN4: Optional Audio output
  • CN5: Stereo EP 3.5MM Female Connector, Stereo Audio Signal Output
  • SW1: Tactile Switch 3D Sound Effect ON/OFF
  • D1: Power LED
  • D2: 3D Sound Function Display

Schematic

Parts List

NO.QNTY.REFDESC.MANUFACTURERSUPPLIER SUPPLIER PART'S NO
11CN14 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5317-ND
21CN23.5MM FEMALE STEREO EP SOCKETCUI AUDIODIGIKEYCP1-3525N-ND
32CN3,CN43 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5316-ND
41CN53.5MM FEMALE STEREO EP SOCKETCUI AUDIODIGIKEYCP1-3525N-ND
51C1100nF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
61C2100uF/16-35V ELECTROLYTIC SMDUNITED CHEMIDIGIKEY565-EMHL250ARA101MF80GCT-ND
71C347uF/25V ELECTROLYTIC SMDPANASONICDIGIKEYPCE3804CT-ND
84C4,C5,C6,C710uF/35V ELECTROLYTIC SMD PANASONICDIGIKEYPCE3947CT-ND
91D1LED RED SMD SIZE 0805LIGHT ON INCDIGIKEY160-1427-1-ND
101D2LED GREEN SMD SIZE 0805DIALLIGHTDIGIKEY350-2044-1-ND
112R1,R21K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
121SW14 PIN TACTILE SWITCHNKK SWITCHDIGIKEYHP0215AFKP2-ND
131U1PT2387 SOIC8PRINCETON TECH CORPDIGIKEYALIEXPRESS

Connections

Gerber View

Photos

 

Video

PT2387 Datasheet

Ground Isolation Audio Amplifier for Automotive Applications

This Ground Isolation Amplifier is developed for car and automotive applications. The board efficiently eliminates problems caused by wiring resistance and removes noise generated by other electrical devices used in automobile environment. In a car or automotive the audio system is grounded to the car body. For this reason, electrical noise generated by the car electrical system can enter the power amplifier input through the chassis and become audible. The BA3123F utilizes the common-mode rejection characteristics of an OPAMP to eliminate this noise. 4 x RCA connectors are provided for easy audio interface. 2x pin header connector is provided for chassis ground.

Features

  • Power Supply 4V to 18V DC
  • Quiescent Current 9mA
  • High Common-mode Rejection Ratio(1Khz) 57dB
  • Low Noise
  • Low Distortion THD 0.002% (Vout 0.7V)
  • Frequency Response 20Hz to 20Khz
  • PCB Dimensions 58.58 x 41.28mm
  • 4 x 2.5mm Mounting Holes

Connections and Other Details

  • CN1: Pin 1,2 = VCC 4V to 18V, Pin 3,4=GND
  • CN2: Connect it to Car Chassis
  • CN3: Connect it to Car Chassis
  • J1: RCA Female Audio Output (Right Channel)
  • J2: RCA Female Audio Output (Left Channel)
  • J3: RCA Female Audio Input (Left Channel)
  • J4: RCA Female Audio Input (Right Channel)
  • D1: Power LED

Schematic

Parts List

NOQNTY.REF.DESC.MANUFACTURERSUPPLIERSUPPLIER'S PART NO
11CN14 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5317-ND
21CN22 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5315-ND
31CN32 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5315-ND
44C1,C4,C7,C84.7uF/35V SMD ELECTROLYTICPANASONICDIGIKEYPCE4296CT-ND
51C2100uF/25V SMD ELECTROLYTICUNITEC CHEMIDIGIKEY565-EMVE250ARA101MF80GCT-ND
61C3100nF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
71C522uF/25V SMD ELECTROLYTICNICHICONDIGIKEY493-10060-1-ND
81C610uF/35V SMD ELECTROLYTICUNITEC CHEMIDIGIKEY565-EMVH350ARA100MF60GTR-ND
91D1LED RED SMD SIZE 0805OSRAMDIGIKEY475-1278-1-ND
104J1,J2,J3,J4RCA JACKCUI AUDIODIGIKEYCP-1418-ND
111R147E 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
121R21K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
131R3620E 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
143R4,R6,R80E SMD SIZE 0805YAGEO/MURATADIGIKEY
152R5,R71.8K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
161U1BA3123 SOIC8ROHMDIGIKEY846-BA3123F-E2TR-ND

Application Diagram

Connections

Gerber View

Photos

Video

BA3123F Datasheet

KiCad Conference 2023 (KiCon) to be held in A Coruña, Spain

The KiCad Conference will be held in person on September 9-10, 2023 at Palacio de Exposiciones y Congresos de A Coruña (Palexco).

KiCad is a free and open-source software suite for the design, simulation, and fabrication of electronic circuits.  It is available worldwide for use on Windows, MacOS, and Linux platforms.

Professionals from all over the world collaborate in the development of this landmark open-source program.  Its feature set compares favorably with solutions costing thousands of euros.

The Kicad Conference is the largest gathering of professional engineers, designers, and makers using KiCad worldwide.

The last face-to-face KiCon took place in Chicago in 2019. From 2020 to 2022 the conference was held online only, in deference to COVID safety measures. 2023, is the year to hold the conference in person again, and Europe was chosen to provide a convenient location for the 100.000+ European KiCad users.  A Coruña was selected as the host city from among other European cities.

The core KiCad developers will be present at KiCon to meet with KiCad users and discuss the future of KiCad.  Wayne Stambaugh, the KiCad project leader will give the keynote address.

Throughout these two days, many talks and training sessions will take place at all levels.  These are targeted at anyone interested in electronics, from the hobbyist to the advanced professional.  Examples of these talks are how to automate tasks, PCB design tricks, how to combine KiCad workflows with other technologies, and more…

For professionals, attending KiCon is a unique opportunity.  Here, you will be able to:

  • Learn from experts: improve your skills by learning from users and more advanced designers, who will talk about what we can expect in the next version of the program, and best practices in design.
  • Network: Meet other professionals to share ideas, talk about challenges, and make contacts that can benefit your company.
  • Keep updated with the latest KiCad trends: KiCad development moves quickly. You will learn about where KiCad is headed and how you can benefit from its future development

If you are interested in contributing or discussing your experiences designing with KiCad, we would love to hear from you!  There is still time to send your proposal! More information at https://kicon.kicad.org

Node Red with MQTT on Raspberry Pi

This tutorial will guide you to integrate the MQTT on Raspberry Pi via the Node-Red platform.

Node-RED is a flow-based development tool for the visual programming of hardware devices, and it is widely used for the Internet of Things. In addition,

Node-RED provides a web browser-based flow editor, which can be used to create JavaScript functions. So, in this tutorial, I’ll teach you how to integrate Qubitro with Raspberry Pi via Node-RED.

Components Required:

This project works without much additional hardware. The one and only requirement is you just need a Raspberry Pi.

Get PCBs for Your Projects Manufactured – (Sponsor)

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You get 10 good-quality PCBs manufactured and shipped to your doorstep for cheap. You will also get a discount on shipping on your first order. Upload your Gerber files onto PCBWAY to get them manufactured with good quality and quick turnaround time. PCBWay now could provide a complete product solution, from design to enclosure production. Check out their online Gerber viewer function. With reward points, you can get free stuff from their gift shop.

What is MQTT?

MQTT stands for Message Queuing Telemetry Transport. MQTT is a machine-to-machine connectivity protocol. It is useful for connections with remote locations where we want to send just a few bytes of data or our sensor values. It is a system where you can publish and receive messages as a client.

By using MQTT you can send commands to control outputs, read and publish data from sensors and much more. Therefore, by using MQTT you can establish communication between multiple devices. Using MQTT you can send a command to a client to control output, or you can read data

from a sensor and publish it to a client. There are two main terms in MQTT i.e. Client and Broker. Let’s discuss what client and broker are.

MQTT Client: An MQTT client is any device that runs an MQTT library and connects to an MQTT broker over a network. Both publishers and subscribers are MQTT clients. The publisher and subscriber refer to whether the client is publishing messages or subscribing to messages.

MQTT Broker: The broker receives all messages, filters the messages, determines who is subscribed to each message, and sends the message to these subscribed clients.

In the last Node Red series, we have seen how to install and use the Node-Red on Raspberry Pi. Just use that one to get started with the Node-Red

Now just start the Node-Red in Raspberry Pi by using this command.

node-red

Next, in your browser, go to the URL mentioned above. The Node-RED dashboard is now visible.

This is how the Node-RED Dashboard page appears.

First, we must install the MQTT Plugin for Node-RED. To do so, go to the menu option.

Choose “Manage Palette” from the drop-down menu.

Install MQTT Plugin by going to Palette and searching for it.

After successful installation, the MQTT In and MQTT Out menus appear in the network section.

Select MQTT Out and add it to the flow, then select Injection Palette and add it to the flow, making a connection between MQTT Out and Injection Palette.

The next stage is to connect the Node-Red to the cloud. For this, we have to use MQTT nodes. You can see those nodes in the node pallets.

We can use the MQTT out node to send our data to the cloud. Open the MQTT out node’s properties. We have to add our MQTT broker’s credentials.

And click on the edit new MQTT broker.

Now we have to add our server details.

Qubitro Cloud Setup

In this, we are going to use Qubitro as a cloud service to store and transfer data.

Login to Qubitro by creating a new account and opening the portal.

Next, create a new project with all your details.

Once you create the project, and add the data source point, you can see multiple data routes. In this, we are going to use MQTT so, select the MQTT as a data point.

Finally, you will see the credentials. We are going to use these credentials to connect the Node-Red with Qubitro.

Node-Red MQTT Setup

Use these configurations with the MQTT Out node.

Next, navigate to the security tab and enter the Device ID and token.

That’s all. Now we are all good. Again, go back to the MQTT Out node and there you can see the topic. Use the Qubitro Device-ID as mqtt topic here.

Finally, deploy the nodes. You can see the connected notification.

Cloud Visualization

Navigate to the Qubitro portal and look at the device page, it will show you the whole node-red data.

Also, Qubitro supports a good dashboard to visualize our data. Navigate to the Qubitro Dashboard and create a new dashboard.

Finally, if you want to share your data with the public means you can share via the public dashboard option in Qubitro.

Here is my sample demo dashboard.

Wrap-Up

So, now we know how to use raspberry pi and MQTT with Node-Red, in the upcoming tutorial we will build a complete automation system via Raspberry Pi and Node-Red.

Danalogx’s Microamp-Meter- High-speed Wi-fi Current Meter and Micro SD card Logger – A Review

MicroAmp-Meter

The DanalogX MicroAmp-Meter is a device that functions as a high-speed Wi-Fi current profiler and Micro SD card logger. The MicroAmp-Meter is a highly efficient portable current meter that can quickly measure and plot the current consumption of embedded devices. It is an excellent tool, and with its automatic shunt-switching mechanism, it is able to measure current levels from 1uA to 1Amp.

Advantages of MicroAmp-Meter

The MicroAmp-Meter is a great device with built-in Wi-Fi that displays the current consumption of the load in a web browser interface, including real-time graphical representation. The bi-directional Wi-Fi communication and remote power cycle control are some of its impressive features. It is an ideal tool for displaying current waveforms over time, similar to an oscilloscope over Wi-Fi. It also comes with a micro SD card slot and logging capability. This device is ideal for field testing as it allows you to measure the current profile over a long period, logging several parameters for over 12 hours. It is incredibly compact and portable, making it easy to carry. Ideally, it has a battery life of over 12 hours!

The MicroAmp-Meter is a reliable device with an automatic shunt-switching mechanism that precisely measures electrical current within the microamps to amps range. This wide range makes accurate and precise current measurements for embedded devices possible. The MicroAmp-Meter boasts a high ADC sampling rate and a core that runs at 80MHz. This device effectively captures noise and other short events by measuring current and voltage 4000 times per second. Its maximum voltage drop of 35 mV across all shunt ranges guarantees the accurate functioning of devices under test.

Wi-Fi-based current monitoring is an excellent approach to simplify the testing process! You can easily monitor the current performance of your device using just your mobile phone, tablet, or PC without the hassle of USB cables. This feature lets you conveniently manage your device from a distance, making it ideal for Hardware-in-the-loop testing.  This great tool empowers us to test devices anytime and anywhere. The MicroAmp-Meter is an ideal pick for students and hobbyists on a budget due to its affordability.

The hardware overvoltage protection circuit clamps the input to the ADC’s range. Due to their minimal forward voltage drop, Schottky diodes are utilized. The 3.3 V system rail that can sink current and the ground are connected to the Schottky diodes. The series resistor that comes after the Schottky diodes also aids in controlling the current flowing into the ADC. Additionally, there are indicators for measured voltage over range on LCD and Buzzer.

The overcurrent protection is handled by software. MicroAmp-Meter automatically turns off output if the current exceeds 1000mA. This feature is implemented with the highest software priority to execute the routine in less than 150us.

Block Diagram

 

Specifications

  • Processor- Dual core ESP32  at 80Mhz. Built-in Websocket server application
    – Each core is pinned to a separate task in RTOS.
    -The primary core of ESP32 reads analog data from external ADC, calculating current and switching shunts accordingly.
    -The secondary core handles LCD, voltage, battery SOC, micro SD card, and Wi-Fi functionalities.
  • Power- 1.8-12V up to 1000 mA
  • Filter- Hardware low pass filter
    – Software butterworth filter
  • Display – 2.4 inch TFT
  • Battery- 1500 mAh LiPo battery
    – Fast charging rate up to 0.6c. Battery charging time is less than two hours.
    – MAX17048G fuel gauge to detect battery SOC.
  • Three shunt stages:
    0-1000 uA
    1-300 mA
    300-1000 mA
  • Low burden voltage (max 30mV)
    Range 1: 30 µV/µA
    Range 2:100 µV/mA
    Range 3: 30 µV/mA
  • Ultrafast shunt switching in less than 200 microseconds.
  • Others-
    -Output control button.
    -TFT brightness control button.
    -Button for SD card logging
    -Button for turning on WIFI
  • Button for LCD brightness adjustment. Save power during SD card logging mode. LCD has 3 brightness levels.
    – Level 0 – Backlight completely turned OFF
    – Level 1 – Backlight intensity 50%
    – Level 2 – Backlight intensity 100%
  • Buffer for voltage over range indication, overload indication, and low battery indication.
  • Dimension- 5.67 cm x 6.9cm

Parameters

  • Current reading (Noise is filtered, and the reading is smoothed out using a Butterworth filter on this parameter)
  • Voltage reading
  • Average current value (T-1 and T time interval). This parameter shows raw current data over 1 second.
  • Current peak value
  • mAh (milliampere-hour). It is the standard for determining a battery’s energy capability. The parameter is highly helpful for determining the DUT battery timing calculation.

The website for this product includes an easy-to-follow guide for starting with the device.

Purchase Information

The Kickstarter page states a $100 or more Pledge to get a MicroAmp-Meter (including 2 x JST Cable). Pledge of $125 or more for MicroAmp-Meter with Micro SD Card/MicroAmp-Meter with Power Adapter. Pledge $150 or more for a complete MicroAmp-Meter Starter Kit. The estimated time of delivery is around Sep 2023.

Sound to RC Servo Driver v2.0 – Arduino Compatible

The project presented here is made for applications such as Animatronics, Puppeteer, sound-responsive toys, and robotics. The board is Arduino compatible and consists of LM358 OPAMP, ATMEGA328 microcontroller, microphone, and a few other components. The project moves the RC servo once receives any kind of sound.  The rotation angle depends on the sound level, the higher the sound level the biggest the movement, in other words, the movement of the servo is proportional to the sound level. The microphone picks up the soundwave and converts it to an electrical signal, this signal is amplified by LM358 op-amp-based dual-stage amplifier, D1 helps to rectify the sinewave into DC, and C8 works as a filter capacitor that smooths the DC voltage. ATmega328 microcontroller converts this DC voltage into a suitable RC PWM signal.

The project is Arduino compatible and an onboard connector is provided for the boot-loader and Arduino IDE programming. Arduino code is available as a download, and Atmega328 chips need to be programmed with a bootloader before uploading the code. Users may modify the code as per requirement. More information on burning the bootloader is here: https://www.arduino.cc/en/Tutorial/BuiltInExamples/ArduinoToBreadboard

Direct Audio Input: The audio input signal should not exceed 5V, It is important to maintain the input audio signal at this maximum level, otherwise it can damage the ADC of ATMEGA328.

Features

  • Supply 5V to 6V DC (Battery Power Advisable)
  • RC Servo Movement 180 Degrees with Loud sound
  • Direct Sound Input Facility Using 3.5MM RC Jack
  • On Board Jumper Selection for Micro-Phone Audio or External Audio Signal
  • On Board Trimmer Potentiometer to Adjust the Signal Sensitivity
  • Flexible Operation, Parameters Can be Changed using Arduino Code
  • PCB Dimensions 44.45 x 36.20 mm

Connections and Other Details

  • CN1 Arduino Programming and Boot-Load Connector: Pin 1 = TX, Pin 2 = RX, Pin 3 = Reset, Pin 4 = GND, Pin 5 = VCC 5V DC, Pin 6 = D11, Pin 7 = D12, Pin 8 = D13
  • CN2 Direct Audio Input: Optional, Pin 1 Audio from External Speaker, Pin 2 = GND
  • CN3 Stereo EP 3.5MM Female Connector for External Audio Signal Input from Speaker
  • CN4 DC Input: Pin 1 VDD 5V to 6V DC, Pin 2 GND
  • CN5: No USE – Optional
  • CN6: RC Servo
  • Jumper J1: Input Signal Source Selection (External Audio Signal or Microphone)
  • PR1 Trimmer Potentiometer: Audio Signal Level Adjust
  • MK1: Condenser Microphone

Arduino Programming

Schematic

Parts List

NOQNTY.REF.DESC.MANUFACTURERSUPPLIER SUPPLIER PART NO
11CN18 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5321-ND
21CN22 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5315-ND
31CN3STEREO SOCKET 3.5MM FEMALECUI DEVICESDIGIKEYCP1-3525N-ND
41CN42 PIN SCREW TERMINAL PITCH 5.08MMPHOENIXDIGIKEY277-1247-ND
51CN53 PIN MALE HEADER PITCH 2.54MM WURTHDIGIKEY732-5316-ND
61CN63 PIN MALE HEADER PITCH 2.54MM WURTHDIGIKEY732-5316-ND
71C110uF/10V CERAMIC SMD SIZE 0805MURATA/YAGEODIGIKEY
86C2,C3,C5,C12,C4,C6100nF/50V CERAMIC SMD SIZE 0805MURATA/YAGEODIGIKEY
91SHUNTSHUNT FOR JUMPERSULLINS CONNCTDIGIKEYS9001-ND
103U3,C7,R10DNP
111C810uF/50V SMD ELECTROLYTICWURTHDIGIKEY732-8451-1-ND
121C9470uF/16V SMD ELECTROLYTICELITEDIGIKEY4191-CEE1C471MCB08A5CT-ND
132C10,C1122PF/50V SMD SIZE 0805MURATA/YAGEODIGIKEY
142D1,D21N4148 SMDONSEMIDIGIKEYFDLL4148CT-ND
151D3LED RED SMD SIZE 0805LITE ON INCDIGIKEY160-1427-1-ND
161J13 PIN MALE HEADER PITCH 2.54MM WURTHDIGIKEY732-5316-ND
171MK1CONDENSOR MICEPUI AUDIODIGIKEY668-1484-ND
186R1,R2,R5,R6,R7,R1110K 5% SMD SIZE 0805MURATA/YAGEODIGIKEY
193R3,R4,R131K 5% SMD SIZE 0805MURATA/YAGEODIGIKEY
201R824K 5% SMD SIZE 0805MURATA/YAGEODIGIKEY
211R91E 5% SMD SIZE 0805MURATA/YAGEODIGIKEY
221R12 1M 5% SMD SIZE 0805MURATA/YAGEODIGIKEY
231U1LM358 SMD SOIC8TIDIGIKEY296-LM358DRCT-ND
241U2ATMEGA328TQPF-32MICROCHIPDIGIKEYATMEGA328PB-AURCT-ND
251X116MhzECS INCDIGIKEYX1103-ND
261PR110K TRIMMER POTKYOCERADIGIKEY478-601030-ND

Connections

Gerber View

Code

/*
 Controlling a servo position using a potentiometer (variable resistor)
 by Michal Rinott <http://people.interaction-ivrea.it/m.rinott>

 modified on 8 Nov 2013
 by Scott Fitzgerald
 http://www.arduino.cc/en/Tutorial/Knob
*/
  
#include <Servo.h>

Servo myservo;  // create servo object to control a servo

int potpin = A2;  // analog pin used to connect the potentiometer
int val;    // variable to read the value from the analog pin

void setup() {
  myservo.attach(6);  // attaches the servo on pin 6 to the servo object
}

void loop() {
  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 60)
  val = map(val, 0, 60, 0, 180);     // scale it for use with the servo (value between 0 and 180)
  myservo.write(val);                  // sets the servo position according to the scaled value
  delay(15);                           // waits for the servo to get there
}

 

Photos

 

Video


Atmega328 Datasheet

Continuous Conduction Mode Pre-Converters Module for Power Factor Controller

This compact module shown here is a Continuous Conduction Mode (CCM) Power Factor Correction Step up Pre-Converter. All-important inputs and output pins are broken out for use in your application, making this board hackable! Please refer to the datasheet of the NCP1654 chip for easy alteration and configuration of the board as per requirements. This board controls the power switch conduction time (PWM) in fixed frequency mode and is dependent on the instantaneous coil current. This module drastically simplifies the PFC implementation scheme. It also integrates high safety features that make the NCP1654 module ideal for robust and compact PFC stages like an effective input power runaway clamping circuit. Please refer to the application schematic to create a powerful PFC using this pre-driver module. The chip is available with various options for frequency such as 65Khz, 133Khz, and 200Khz. Choose the appropriate chip as per frequency requirement This project is tested with a 65Khz oscillator chip.

Features

  • Supply 15V DC
  • ±1.5 A Totem Pole Gate Drive, can drive TO247 and TO220 MOSFETS
  • Average Current Continuous Conduction Mode
  • Fast Transient Response
  • Very Few External Components
  • Very Low Startup Currents (< 75 uA)
  • Very Low Shutdown Currents (< 400 uA)
  • Low Operating Consumption
  • Accurate Fully Integrated 65
  • Latching PWM for cycle−by−cycle Duty−Cycle Control
  • Internally Trimmed Internal Reference
  • Undervoltage Lockout with Hysteresis
  • Soft−Start for Smoothly Startup Operation
  • Shutdown Function
  • PCB Dimensions 26.04 x 17.94mm

Safety Features

  • Inrush Current Detection
  • Overvoltage Protection
  • Undervoltage Detection for Open Loop Detection or Shutdown
  • Brown−Out Detection
  • Soft−Start
  • Accurate Overcurrent Limitation
  • Overpower Limitation

Connections Connector CN1

  • Pin 1 = VCC 15V DC, Pin 2 = GND, Pin 3 = BO Brown-Out/IN, Pin 4 = CS, Pin 5 = NC, Pin 6 = GND, Pin 7 = Output (MOSFET Gate), Pin 8 = VCC 15V DC, Pin 9 = NC, Pin 10 = FB/Feedback Voltage
  • D1 Power LED

VCC

This pin is the positive supply of the IC. The circuit typically starts to operate when VCC exceeds 10.5 V and turns off when VCC goes below 9 V. After start−up, the operating range is 9 V up to 20 V.

CS (Current Sense)

This pin sources a current ICS which is proportional to the inductor current IL. The sense current ICS is for overcurrent protection (OCP), overpower limitation (OPL) and PFC duty cycle modulation. When ICS goes above 200 uA, OCP is activated and the Drive Output is disabled.

BO (VBO) Brow-Out/In

BO pin detects a voltage signal proportional to the average input voltage. When VBO goes below VBOL, the circuit that detects too low input voltage conditions (brown−out), turns off the output driver and keeps it in low state until VBO exceeds VBOH. This signal which is proportional to the RMS input voltage Vac is also for overpower limitation (OPL) and PFC duty cycle modulation.

VFB (Voltage Feedback/Shutdown)

This pin receives a feedback signal VFB that is proportional to the PFC circuit’s output voltage. This information is used for both output regulation, overvoltage protection (OVP), and output Undervoltage protection (UVP) to protect the system from damage at feedback abnormal situations. When VFB goes above 105% VREF, OVP is activated and the Drive Output is disabled. When VFB goes below 8% VREF, the device enters a low−consumption shutdown mode.

OP (Drive Output)

The high current capability of the totem pole gate drive (±1.5 A) makes it suitable to effectively drive high gate charge power MOSFET

Schematic

Parts List

NO.QNTY.REF.DESC.MANUFACTURERSUPPLIERSUPPLIER'S PART NO
11CN110 PIN MALE HEADER RIGHT ANGLE PITCH 2.54MMWURTHDIGIKEY732-2670-ND
21C11KPF(1nF)/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
31C2DNP
41C30.47uF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
51C42.2uF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
61C5220KF(0.22uF)/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
71C610uF/25V CERAMIC SMD SIZE 1210 OR 1206YAGEO/MURATADIGIKEY
81C70.1uF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
91C810PF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
101D1LED RED SMD SIZE 0805OSRAMDIGIKEY475-1278-1-ND
112R1,R23.3M 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
122R7,R80E SMD SIZE 1206YAGEO/MURATADIGIKEY
131R43.6K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
142R5,R61.8M 5% SMD SIZE 1206YAGEO/MURATADIGIKEY
151R91K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
161R1047K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
171R1122K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
181R1282K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
191R1312K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
201R141.2K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
211R15499E 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
221U1NCP1654BD65R2GONSEMIDIGIKEYNCP1654BD65R2GOSCT-ND
231R30E SMD SIZE 0805YAGEO/MURATADIGIKEY

Connections

Block Diagram

Application Schematic

Functional Block Diagram

Gerber View

Photos

NCP1654 Datasheet

Precision Thermocouple Amplifiers with Cold Junction Compensation – Temperature Range −25°C to +400°C

This Thermocouple Amplifier project provides a simple, low-cost solution for measuring thermocouple temperature. This board simplifies many of the difficulties of measuring thermocouples output. An integrated temperature sensor performs cold junction compensation. A fixed-gain instrumentation amplifier amplifies the small thermocouple voltage to provide a 5 mV/°C output. The high common-mode rejection of the amplifier blocks common-mode noise that the long thermocouple leads can pick up. For additional protection, the high impedance inputs of the amplifier make it easy to add extra filtering. The module can be used as standalone thermometers or as switched output setpoint controllers using either a fixed or remote setpoint control. The module can be powered from a single-ended supply (less than 3V) and can measure temperatures below 0°C by offsetting the reference input. To minimize self-heating, an unloaded AD8495 typically operates with a total supply current of 180 μA, but it is also capable of delivering in excess of ±5 mA to a load. The board can be interfaced with K-type (chromel-alumel) thermocouples. With an operating single supply of 5V, the 5 mV/°C output allows the devices to cover nearly 1000 degrees of a thermocouple’s temperature range. The project can also work with 3V supplies, allowing them to interface directly with lower-supply ADCs. They can also work with supplies as large as 36V in industrial systems that require a wide common-mode input range. The AD8495 cold junction compensation is optimized for operation in a lab environment, where the ambient temperature is around 25°C. The AD8495 is specified for an ambient range of 0°C to 50°C.

Features

  • Supply Dual 5V DC (+/-5V DC)
  • Low cost and easy to use
  • Measurement Temperature Range −25°C to +400°C
  • ±2°C Accuracy Temperature Ranges
  • Pretrimmed for K-type thermocouples
  • Internal cold junction compensation
  • High-impedance differential input
  • Standalone 5 mV/°C thermometer
  • Reference pin allows offset adjustment
  • Mode: Linear, Set Point Controller, Hysteresis on Setpoint Controller, Selection Using Jumpers
  • Thermocouple break detection
  • On Board Power LED
  • 4 x 2.5mm Mounting Holes
  • PCB Dimensions 31.12 x 27.31mm

Applications

  • K-type thermocouple temperature measurement
  • Setpoint controller
  • Celsius thermometer
  • Universal cold junction compensator
  • White goods (oven, stove top) temperature measurements
  • Exhaust gas temperature sensing
  • Catalytic converter temperature sensing

The board is designed to allow users to quickly prototype the precision thermocouple amplifiers for various user-defined configurations for different applications. The circuit has three modes of operation: linear mode, setpoint controller mode, and hysteresis on setpoint controller mode. Various modes can be set using onboard jumpers.

Linear Mode: Jumper J2, J3, J5 = Open, Jumper J1 = Closed, J4=GND

The linear mode can be selected by closing Jumper J1 and J4 = GND linear, the output voltage of the AD8495 is calculated as follows:

VOUT = (T_MJ × 5 mV/°C) + VREF

where T_MJ is the thermocouple measurement junction temperature.

Setpoint Controller Mode: Jumper J1, J3, J5 = Open, Jumper J2 Closed and J4=GND, CN1 Pin 5 Set Point Voltage input, Pin 4 = High or Low Output

The board operates as a temperature setpoint controller when configured with either a thermocouple input from a remote location or with the AD8495 being used as a temperature sensor. When the measured temperature is below the setpoint temperature, the output voltage goes to −VS. When the measured temperature is above the setpoint temperature, the output voltage goes to +VCC. For optimal accuracy and common mode rejection ratio (CMRR) performance, the setpoint voltage must be created with a low-impedance source. If the setpoint voltage is generated with a voltage divider, a buffer is recommended.

Hysteresis on Setpoint Controller Mode: Jumper J1, J5=Open, J4 = Resistor Divider R5/R6, J3=Closed, J2=Closed  

Hysteresis can be added to the setpoint controller by using a resistor R5, R6 divider from the output to the reference pin, The resistors installed on the board are 1 kΩ and 100 kΩ, which creates a window of approximately 10°C around the setpoint temperature for a +VCC of 5 V.

Measuring Negative Temperatures

The board can measure negative temperatures using either single or dual supplies. When operating on dual supplies with the J4 jumper = GND   position (reference pin grounded), a negative output voltage indicates a negative temperature at the thermocouple measurement junction. When operating the board series evaluation board on a single supply level, apply a positive voltage (less than +VS) on the reference pin to shift the output. The jumper from J2 must be removed so that the reference pin is not grounded. An output voltage less than VREF indicates a negative temperature at the thermocouple measurement junction.

Thermocouple Break Detection

The board offers open thermocouple detection. The inputs of the AD8495 are PNP type transistors, which means that the bias current always flows out of the inputs. Therefore, the input bias current drives any unconnected input high, which rails the output. Resistor R4 connected to GND causes the AD8495 output to rail high in an open thermocouple condition.

Gain Error

Gain error is the amount of additional error when measuring away from the measurement junction calibration point. For example, if the part is calibrated at 25°C and the measurement junction is 100°C with a gain error of 0.1%, the gain error contribution is (100°C − 25°C) × (0.1%) = 0.075°C. This error can be calibrated with a two-point calibration if needed, but it is usually small enough to ignore.

Ambient Temperature Rejection

The specified ambient temperature rejection represents the ability of the AD8495 to reject errors caused by changes in the ambient temperature/reference junction. For example, with 0.025°C/°C ambient temperature rejection, a 20°C change in the reference junction temperature adds less than 0.5°C error to the measurement.

Input Voltage Protection

The board has very robust inputs. Input voltages can be up to 25 V from the opposite supply rail. For example, with a +5 V positive supply and a −3 V negative supply, the board can safely withstand voltages at the inputs from −20 V to +22 V. Voltages at the reference and sense pins should not go beyond 0.3 V of the supply rails.

Connections and Other Details

  • CN1: Pin 1 = VCC +5V DC, Pin 2 = GND, Pin 3 = -VEE -5V, Pin 4 Temperature V-Output, Pin 5 = Sense (No Use), Pin 6 = Set Point V-Input
  • CN2: Pin 1 = K Type Sensor + Input, Pin 2 = Sensor -Input
  • Jumper J1: For Set the Linear Output
  • Jumper J2: For Set Point Input Mode
  • Jumper J3: For Hysteresis on Setpoint Controller Mode
  • Jumper J4: For Reference Ground or Hysteresis Selection
  • Jumper J5: Closed for Single Supply Input, Open for Dual Power Supply Input (Solder Jumper)

Schematic

Parts List

NO.QNTY.REF.DESC.MANUFACTURESUPPLIER SUPPLIER PART NO
11CN16 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5319-ND
21CN2TEMPERETURE SENSOR CONNECTORLABFACILITYELEMENT143810628
32C1,C310uF/16V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
42C2,C4100nF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
52C5,C710nF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
61C61uF/25V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
71D1LED RED SMD SIZE 0805OSRAMDIGIKEY75-1278-1-ND
83J1,J2,J3JUMPER- 2 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5315-ND
91J4JUMPER-3PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5316-ND
101J5PJMP-PCB SOLDER JUMPER
113R1,R6,R71K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
122R2,R3100E 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
131R41M 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
141R5100K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
151U1AD8495 SOIC8ANALOG DEVICESDIGIKEYAD8495ARMZ-R7CT-ND
164SHUNTSHUNT-JUMPERSULLINS CONNCTDIGIKEYS9001-ND

Connections

Gerber View

Photos

Video


AD8495 Datasheet

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