In this Instructable, you will learn how easy it is to send and receive SMS messages over GSM with Arduino.
One of the essential elements of building IoT project is the ability to connect devices. Wi-Fi and Bluetooth are good low cost choices, but they work only at close ranges, or in hotspot areas. When the device needs to be at a remote location GSM is a good and easy to setup option.
Send and Receive SMS with GSM SIM900 Arduino Shield – [Link]
This tutorial is going to teach you some basics on using Stepper Motor while interfacing with Arduino and Stepper Motor Driver.
Bipolar Stepper Motor is DC motor that move in discrete steps. It has multiple coils that are organized in groups called “phases”. By energizing each phase in sequence, the motor will rotate, a step at a time. In order to be able to move the motor, you will need a motor driver. Thus, stepper motor driver A4988 is designed to play this role. A4988 stepper motor driver comes with heat sink. This stepper motor driver lets you control one bipolar stepper motor at up to 2 A output current per coil.
How to Interface Stepper Motor With Arduino – [Link]
A ESP8266 temperature logger project from Facelesstech:
I decided to use the esp-01 module because I only need 2 GPIO pins since I was using the DS18B20 temp sensor and the WS2812 LED. This made the hardware really cheap and easy to reproduce too. I normally use FTDI boards when it comes to the USB to serial on my projects but I couldn’t find a FTDI board with micro USB that didn’t cost the earth. That’s why I went with the CP2102 which I hadn’t used before.
I think what really made me feel good about this project was the fact that I came up with the idea to use a Full sided male USB port for power teamed with a AMS1117 3.3v voltage regulator. This would allow me to just plug this straight into a USB wall wart or a phone charger battery bank.
ESP8266 temperature logger – [Link]
Lars Keuninckx @ edn.com writes:
The Design Idea circuit shown below is a simple implementation of an iterated unimodal map, reminiscent of the logistic or Verhulst map encountered in the study of nonlinear dynamics. It is useful to show chaotic discrete-time dynamics to students, or as a random number generator. Specifically, the circuit implements: Vk+1 = rF(Vk), where F is a nonlinear unimodal function (a “bump”), implemented by the circuit in the dashed box. The response of this circuit is shown in the Vout vs. Vin plot.
Iterated-map circuit creates chaos – [Link]
Have an old cell phone laying around? Don’t know what to do with it? What if I told you that you could turn that old cell phone into a smartwatch!
What I’d like to do for this crazy/ambitions project is turn an old cell phone into a smartwatch. So obviously an old cell phone is required. The primary reason for this project is simply that I had an old cell phone laying around and wanted to find a creative way to repurpose it. The one I had is a Nokia 1100, but most other old cell phones would work, so long as you can find the schematics for the LCD online
Make Your Own Smartwatch From An Old Cell Phone – [Link]
The new PIC32MM family, currently Microchip’s lowest power 32-bit PIC32 family, features sleep modes down to as little as 500 nA. Filling the gap between the PIC24F XLP and PIC32MX families, the new family also offers so-called core independent peripherals that once initialized can function without intervention of or loading the MCU core.
New PIC32MM consumes as little as 500 nA – [Link]
Melexis (Tessenderlo, Belgium) has added the MLX91210 family of integrated sensors; operating from a 5V supply, the ICs have current sensitivity levels down to 26.7 mV/A and support linear current measurement ranges that span as far as ±75A corresponding to 30 ARMS current. Available in SO8 and SO16 package formats, these fully integrated Hall-effect current sensors have extremely low resistive curent-path losses (0.8 mΩ for the SO8 and 0.7 mΩ for the SO16) and provide high voltage isolation ratings (2.1 kVRMS and 2.5 kVRMS respectively), as well as accelerated responsiveness (within 5 µsec). The sensor output of each IC is factory-calibrated for a specific current range and compensated for optimal stability in relation to temperature and over the course of its working lifespan, so that long term accuracy is maintained.
Hall-effect current sensing replaces shunt-resistive measurements – [Link]
Sanket Gupta pointed us to his latest article, on how to select an inductor and discuss about the various types of them.
Inductors are two-terminal components used for filtering, timing and power electronics applications. They store energy in the form of magnetic fields as long as a current is flowing. Inductors oppose a change in current by inducing an electromotive force (or e.m.f) according to Lenz’s Law. The inductor can be approximated as an open circuit for AC signals and as a short circuit for DC signals. The unit of inductance is Henry (H) .
How To Select an Inductor – [Link]
ArduCAM has introduced a tiny Raspberry Pi compatible module based on Broadcom’s BCM2835 Processor, the same chip found in the original Raspberry Pis A, B, B+ and Zero. This module is tiny, measuring only 24 x 24mm and it is compatible with all of the software that makes the Raspberry Pi so popular. It comes with 256MB/512MB LPDDR2 Memory, Camera CSI Interface x2, USB, AV output, SPI, UART, I2C, GPIO and weights only 2g. The board isn’t finalized and it isn’t for sale yet.
ArduCAM team now is developing a coin size Raspberry Pi compatible compute module. The total size of the SOM is 24mm x 24mm, compared to the offical Raspberry Pi compute module and new Pi ZERO, it will be the smallest Raspberry Pi compatible module in the world. The coin size pi compute module is fully customizable and can offer the extra features that wasn’t provided by the standard Raspberry Pi boards. User can run the system on a small 36mm x 36mm adapter mother board with camera support. It is ideal for battery powered portable device like smart watch, action camera etc. The highlight feature of this coin size pi module, it supports dual camera interface and stereo vision which can be used in robots for machine vision applications or high definition drone camera.
ArduCAM Introduces tiny Raspberry Pi compatible board – [Link]
Vasily Ivanenko made a VXO-based synthesizer:
To make a VXO to mix with a ~7 MHz VCO, you’ll need a crystal that is higher in frequency than the highest frequency you want to synthesize. Some rummaging revealed a bag of 21.4773 MHz crystals that I could divide by 3 to garner 7.159 MHz.
To afford a reasonable delta F, three were placed in the super VXO fashion and I applied the smallest amount of series inductance that would ensure a reasonable delta F with solid frequency stability.
VXO – based PLL frequency synthesizer for 7 MHz – [Link]
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