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Xassette-Asterisk RISC-V 64 SBC Features Allwinner’s latest D1s SoC and Sells for Less Than $10

Posted on 15 November, 202115 November, 2021 by Emmanuel Odunlade

Open-source embedded system framework has made processor and SBC innovation more fun and easy, offering many configurable architecture implementations. The RISC-V ISA based hardware, though not very economical, is still very much celebrated even after more than a decade of its existence. So far, we have seen it in a number of devices including the Allwinner D1 based Nezha RISC-V Linux SBC currently sold for a little over $100, and the SdtElectronics’s Xassette-Asterisk, an evaluation board based on Allwinner’s latest D1s SoC coming out for under $10.

Xassette-Asterisk SBC features Allwinner’s single-core RISC-V 64 SoC, F133/D1s, which runs at 1.008GHz with an inbuilt 64MB DDR2, and an operating input voltage of 5V supplied via a USB-C port or 3.3V via pin header. The SBC also features digital and analog interfaces including USB ports, micro-SD slot, LCD connector, and headphone interface in a compact 56×56 mm – 2 layer board. According to SdtElectronics, the SBC has been tested with an 800×480 parallel LCD even though the F133 manual reveals support for up to 1920×1080 parallel LCD. The board, however, does not feature GMAC and WiFi modules, which the designer claims are to reduce complexity and cost, but it still supports easy internet access. SdtElectronics also claims that networks can be shared with a computer via RNDIS Gadget, a USB Ethernet support protocol of Linux-Sunix.

Key Features and Specifications of the board:

1.008 GHz, 64MB DDR2, Allwinner D1s single-core 64-bit RISC-V chip
MicroSD card slot, 32 MBit SPI flash
40-pin LCD interface, 6-pin touch panel interface, backlight power
24-pin MIPI CSI interface
Headphone with mic jack (3.5mm), Line-in jack (3.5mm)
1x USB Type-C OTG port
1x USB Type-C host port (1)
34-pin GPIO header with SPI, I2C, UART, PWM, DAC, ADC, IR Tx, R, power (5V, 3.3V, and GND)
3-pin UART header (serial console usable)
Reset button
Power Supply:
- 5V via USB-C port
- 3.3V via pin header (Not supported by USB due to absence of 5V)
Dimension: 56mm x 56mm

The Xassette-Asterisk is an open-source hardware product based on the Linux OpenWrt framework. The project’s log added a few days ago claims that D1s only boots the Tina Linux with limited functionality. So, the root directory of the Linux system had been modified to run the Ubuntu filesystem. SdtElectronics also claims that the package manager alongside Internet access supports high software packages. Documentary on PCB and schematics is available on the Github repository.

The Xassette-Asterisk is not for commercial purposes, but its progress is logged at Hackaday In case you want to join the project and build your board. You might have to purchase the Allwinner processor from Taobao for about $5.5 too.

Seeed’s $799 Jetson SUB Mini PC Kit Combines Leetop’s A206 carrier board with a Xavier NX Module

Posted on 15 November, 2021 by Emmanuel Odunlade

Seeed Studio has launched a Jetson SUB Mini PC Kit designed for AI applications. The 130 mm x 120 mm x 50mm combines Xavier NX module with an A206 carrier board from Leetop.

The Jetson Xavier NX module delivers up to 21 TOPS and with 384 NVIDIA CUDA cores, 48 Tensor cores, Hexa-core Carmel 64-bit ARM CPUs, and two NVIDIA deep learning accelerators engines. The module is also said also offer 8GB LPDDR4x and 8-32GB eMMC 5.1, and preloaded with Nvidia’s Ubuntu-powered Jetpack SDK for tapping it’s AI capabilities.

The Leetop A206 carrier board on the other hand has a number of features including dual MIPI-CSI camera interfaces, a CANBus header, and 40-pin GPIO. The module also has a real-time clock with coin cell socket, a 15V/3A DC input, and a -25 to 80° operating temperature range.

The Jetson SUB mini PC also comes with a case, a heat sink, and a fan. There’s also a 512GB SSD, WiFi and BT, GbE, HDMI, DP, and 4x USB. The kit is ideal for high-performance compute and AI in embedded and edge systems. It is a choice platform for running modern neural networks in parallel and process high-resolution data from multiple sensors simultaneously.

Features and Specifications of the Jetson SUB mini PC include:

NVIDIA Jetson Xavier NX module with:
- 6-core NVIDIA Carmel ARMv8.2 64-bit processor with 6 MB L2 + 4 MB L3 cache
- NVIDIA Volta architecture with 384 NVIDIA CUDA cores and 48 Tensor cores
- 2x NVDLA Engines, 7-Way VLIW Vision Processor
- Multiple 4Kp60 encode, multiple 8Kp30/4Kp30 decode
- 8 GB 128-bit LPDDR4x 51.2GB/s
- 10 W | 15 W | 20 W
- Up to 14 TOPS @ 10 W, Up to 21 TOPS @ 20W
1x MicroSD slot
M.2 Key M socket fitted with a 128GB NVMe SSD
HDMI and DisplayPort
2x MIPI CSI-2 D-PHY lanes compatible with Raspberry Pi HQ camera and RPi V2 camera
Gigabit Ethernet
WiFi & Bluetooth via M.2 Key-E card (included)
4x USB 3.1 ports
USB 2.0 Micro-B
Header with GPIOs, I2C, I2S, SPI, UART
Power supply: 9 to 19V DC via power barrel jack
Dimensions: 130 mm x 120 mm x 50 mm

The mini PC kit comes with everything needed in terms of hardware and software already installed and set up. It is available for order at $799. Shipping already started on the 5th November this year. You will get it with an acrylic cover, an aluminum frame and two external antennas.

Other useful details on the Jetson SUB Mini PC Kit may be found on Seeed’s Jetson SUB and the A206 carrier board product pages.

STEVAL-L6986IV1 Synchronous Iso-Buck Converter Evaluation Board

Posted on 15 November, 2021 by mixos

STMicroelectronics’ evaluation board with dual isolated output is based on the L6986I

STMicroelectronics’ 38 V, 5 W synchronous iso-buck converter evaluation board generates two isolated voltages (approx. +18 V and between -4 V and -5 V), suitable for supplying IGBT/SiC MOSFET gate drivers or a single isolated voltage using a simple bypass. The board features the L6986I switching converter allowing a fine and adjustable primary output voltage and an isolated secondary output generated using a transformer.

The primary sink capability (typ. 1.9 A) allows appropriate energy transfer to the secondary side and enables a tracked soft-start of the secondary output. The control loop is based on a peak current mode architecture with the device operating in forced PWM. The 300 ns blanking time filters oscillations generated by the transformer leakage inductance and renders the solution more robust.

Pulse-by-pulse current sensing on both power elements implements effective constant current protection on the primary side. At the same time, the secondary output is protected against short-circuit events because of the primary reverse current limit. The secondary voltage is stabilized over current with a power transistor and a shunt voltage reference (TL431).

Features

Designed for iso-buck topology
4 V to 38 V operating input voltage
Primary output voltage regulation/no optocoupler required
1.9 A typical sink peak primary current capability
Peak current mode architecture in forced PWM operation
300 ns blanking time
8 µA I_Q-SHTDWN
Adjustable f_SW and synchronization
Embedded primary output voltage supervisor
Adjustable soft-start time
Internal primary current limiting
Overvoltage protection
R_{DS(ON) HS} = 180 mΩ, R_{DS(ON) LS} = 150 mΩ
Thermal shutdown

more information: https://www.st.com/en/evaluation-tools/steval-l6986iv1.html

LTC3337 Primary Battery State of Health Monitor

Posted on 15 November, 202115 November, 2021 by mixos

Analog Devices Inc. LTC3337 Primary Battery State of Health (SOH) Monitor provides accurate, real-time readings of battery cell discharge, voltage, impedance, and temperature. The LTC3337 is designed to be placed in series with a primary battery with minimal associated series voltage drop. This device integrates an infinite dynamic range coulomb counter that tallies all accumulated battery discharge and stores it in an internal register accessible via an I²C interface. A discharge alarm threshold based on this state of charge (SOC) is programmable. When it is reached, an interrupt is generated at the IRQ pin. Coulomb counter accuracy is constant down to no load.

To accommodate a wide range of primary battery inputs, the peak input current limit of the LTC3337 is pin selectable from 5mA to 100mA.

Coulombs can be calculated for either the BAT_IN or BAT_OUT pin, determined by the AV_CC pin connection. A BAL pin is provided for applications utilizing a stack of two supercapacitors (optional) at the output.

The Analog Devices Inc. LTC3337 Primary Battery State of Health Monitor is available in a 12-lead Lead Frame Chip Scale Package (LFCSP) with an exposed pad for improved thermal performance.

Features

8.0V to 5.5V battery input voltage range
100nA quiescent current
8 primary battery peak input current limits
- 5mA, 10mA, 15mA, 20mA, 25mA, 50mA, 75mA, 100mA
SOH monitor for primary battery
- Integrated coulomb counter (Q)
- Additional monitors for battery voltage (V), battery impedance (Z), and temperature (T)
Integrated ±10mA supercapacitor balancer
Primary battery current (BAT_IN) or load current (BAT_OUT) is counted
Programmable coulomb counter prescaler for a wide range of battery sizes
Programmable discharge alarm threshold with interrupt output
I²C interface
-40°C to +125°C operating junction temperature range
2mm x 2mm LFCSP-12 package

Block Diagram

Application Circuit

more information: https://www.analog.com/en/products/ltc3337.html

Diodes Incorporated AP22816/17/18 Power Distribution Load Switches

Posted on 15 November, 2021 by mixos

Diodes Incorporated AP22816/17/18 1A/1.5A/2A Power Distribution Load Switches are single-channel, current-limited, integrated high-side power switches optimized for Universal Serial Bus (USB) and other hot-swap applications. The AP22816/17/18 are available with both polarities of enable input and comply with USB standards.

The Diodes Inc AP22816/17/18 Power Distribution Load Switches feature a 1A, 1.5A, or 2A output current, fast short-circuit response time, and an integrated output discharge function to ensure completely controlled discharging of the output voltage capacitor. The switches offer a complete protection solution with reverse current blocking, overcurrent, overtemperature, and short-circuit protection, as well as controlled rise time and undervoltage lockout functionality. The 6ms deglitch capability on the open-drain flag output prevents false overcurrent reporting and requires no external components.

The AP22816/17/18 Switches are available in the standard Green and RoHS compliant TSOT25 and MSOP-8 packages.

Features

Input voltage range of 2.7V to 5.5V
Logic level Enable pin available with active-high or active-low versions
Protections:
- 2kV HBM, 500V CDM ESD Protection
- Overcurrent protection with auto-recovery
- Short-circuit protection with auto-recovery
- Overtemperature protection with auto-recovery
- Output reverse current / voltage protection
75mΩ On-resistance
Built-in soft-start with 0.6ms typical rise time
Fault report (FLG) with blanking time (6ms Typ.)
Thermally efficient low profile package
Level 1 per J-STD-020 moisture sensitivity
Finish–matte tin-plated leads, solderable per MILSTD-202, Method 208 terminals
Totally lead-free and fully RoHS compliant
Halogen and antimony free

Application Circuit

Block Diagram

more information: https://www.diodes.com/part/view/AP22816B

OSRAM Opto Semiconductors OSLON Square GH CSBRM4.24 Hyper Red LEDs

Posted on 15 November, 202115 November, 2021 by mixos

OSRAM Opto Semiconductors OSLON® Square GH CSBRM4.24 Hyper Red LEDs are optimized for horticulture. These LEDs feature a unique and innovative radiation pattern designed to illuminate plants evenly for uniform growth while reducing the number of luminaires required. The high-power GH CSBRM4.24 LEDs provide excellent reliability, a long lifetime, and low thermal resistance in a compact footprint.

The OSRAM Opto Semiconductors OSLON® Square GH CSBRM4.24 Hyper Red LEDs feature an ultra-compact 3.0mm x 3.0mm footprint ideal for high-density arrays.

Features

3.0mm x 3.0mm SMD ceramic package with silicon lens
150° radiation
Very low thermal resistance
Superior robustness for a long lifetime
100mA to 1400mA forward current (I_F)
1500mA maximum surge current (I_FS)
660nm peak wavelength (λ_peak)
646nm to 666nm centroid wavelength; 657nm typical (λ_centroid)
640nm dominant wavelength (λ_dom)
20nm spectral bandwidth at 50% I_rel,max(∆λ)
140° viewing angle at 50% I_V (2φ)
1.80V to 2.20V forward voltage; 2.00V typical (V_F)
Corrosion robustness class: 3B
ESD: 8kV according to ANSI/ESDA/JEDEC JS-001 (HBM, Class 3B)
Radiant flux: 1050mW typical @ 700mA; 526mW typical @ 350mA
Radiant efficiency: 74% typical @ 700mA; 80% typical @ 350mA
Photosynthetic photon flux: 5.69μmol/s typical @ 700mA; 2.88μmol/s typical @ 350mA
Photon flux efficacy: 5.72μmol/J typical @ 700mA; 2.89μmol/J typical @ 350mA
-40°C to +125°C operating temperature range

more information: https://www.osram.com/ecat/OSLON%C2%AE%20Square%20GH%20CSSRM3.24/com/en/class_pim_web_catalog_103489/prd_pim_device_5516891/

Bourns SRF7035A Common Mode Chokes

Posted on 15 November, 202115 November, 2021 by mixos

Bourns SRF7035A Common Mode Chokes are AEC-Q200 compliant and offer an 80V_DC rated voltage and -40°C to +125°C temperature range. These chokes feature a compact size and high impedance over a broad frequency range to suppress electromagnetic interference (EMI) coming into or leaving the system. SRF7035A chokes have shielded construction, separated winding, and a sector-wound configuration. Bourns SRF7035A Common Mode Chokes are ideal for use in DC/DC converters, switch-mode power supplies, and power system noise suppression in industrial, consumer, and other electronics.

Features

Shielded construction – low radiation
Separated winding
High current capability
Compact design
AEC-Q200 compliant
RoHS compliant
Halogen free

Specifications

4µH to 22.6µH inductance range
300Ω to 3000Ω impedance range at 1MHz
1.2A to 5A current range
80V_DC rated voltage
-40°C to +125°C temperature range
7mm x 6mm x 3.5mm dimensions

more information: https://www.bourns.com/docs/technical-documents/featured-product-bulletins/Bourns_IC2194_SRF7035A_NPR.pdf

TinyLoad – Simple Electronic Load based on ATtiny45/85

Posted on 15 November, 202115 November, 2021 by mixos

TinyLoad is a simple electronic constant current dummy load. The ATtiny measures voltage, current and temperature of the heat sink, calculates power, energy and battery capacity, controls the fan and displays all relevant data on the OLED. The button is used to switch between power/resistance and energy/capacity display.

The electronic load control circuit, which essentially consists of a potentiometer, an operational amplifier, a MOSFET and a shunt resistor, ensures that the same current flows regardless of the voltage applied.

For this purpose, a 100 milliohms shunt consisting of three 300 milliohms resistors in parallel for proper heat dissipation is located in the load circuit, via which the current is measured. The LMV358 rail-to-rail OpAmp compares this with the target value, which is specified via a 10-turn 10k potentiometer and a 100k resistor and accordingly controls the gate of an IRL540N logic level power MOSFET, which in turn adjusts the current through its internal resistance set in this way. The current measured at the shunt is also amplified by a second OpAmp and measured by the ADC of the ATtiny. The voltage is measured using a voltage divider. The temperature of the MOSFET is measured by a 10k 3950B NTC thermistor. If necessary, the fan is switched on via a MOSFET.

Measurements

For the most accurate measurement possible with maximum measurement resolution, both the 5V supply voltage and the two internal reference voltages in connection with the ADC of the ATtiny are used. First, the supply voltage and the 2.56V reference are measured using the 1.1V reference and corresponding calibration factors are calculated. For each pending measurement, it is first checked which of the three voltage references (5V, 2.56V or 1.1V) is most suitable. This is then used for the measurement via the ADC. For all ADC measurements, the ATtiny is set to sleep mode in order to avoid noise that is generated by the MCU (ADC noise canceler). To further increase the measurement resolution, 64 measurements are carried out in succession (oversampling) and the measured values are added up. The averaging is only carried out at the end of the further calculations in order not to lose any measurement resolution. The measurement accuracy depends essentially on the accuracy of the internal 1.1V reference. This can be calibrated manually if necessary.

Schematic

References

source: https://github.com/wagiminator/ATtiny85-TinyLoad

Logic NOT Function

The logic NOT function’s output state is NOT the same as its input state. The logic NOT function performs the inversion function on its input and outputs complement of the input. The logic NOT function output is false when its input is true, and true when its input is false. It is the simplest logic function having a single input and a single output.

The Boolean expression of a logic NOT function is represented by overline or bar (¯) over its input. This bar or overline denotes an inversion or complement of the state or input. The logic NOT function is performed by logic NOT gates and is sometimes referred to as inverters (as they perform inversion function). The symbol of a logic NOT gate along with expression is shown in the following figure.

Symbol of NOT gate — Figure 1: The logic NOT symbol

The output of the logic NOT symbol has a bubble (o) at the output which denotes an inversion of the signal and, therefore, is called an “Inversion Bubble”. The counterpart of an Inverter is a Buffer that does not invert the signal and performs just amplification of the signal.

Presentation of NOT Function using Switch

The logic NOT function can be illustrated with the help of the following diagram. In the figure, a lamp along with two switches is shown. The switches’ positions are inverse or complemented with respect to each other. The switch without bar or overline represents the logical input (X) and the switch with bar or overline is the inverted state of the input (X). The logical states of “0” & “1” represent a switch with “Open” & “Closed” positions, respectively.

Figure 2: Logic NOT function using switches with Lamp OFF

When the input is TRUE or switch (X) is in the close state then its complement switch will be opened and the lamp will remain OFF whilst the input (X) is in ON state.

Figure 3: Logic NOT function using switches with Lamp ON

However, when input is FALSE or switch (X) is in the open state then its complement switch will be closed and the lamp will turn ON whilst the input (X) is in OFF state.

From the above scenarios, it is clear that the lamp state represents an inversion with the respect to the input (X).

Logic NOT Truth Table

The truth table of a logic NOT gate is shown below.

Boolean Algebra Laws

In the Boolean Algebra, the complementation law involves logic NOT function and is shown in the following figure where it performs the inversion function.

Construction of Other Logic Gates

The logic NAND and NOR gates can be constructed by placing the logic “NOT” gate at the output of logic “AND” and “OR” gates, respectively. The NAND and NOR gates are termed Universal Logic Gates as they can be used to make any other logic. Similarly, cascading two logic NOT gates reverts back to the original input signal and this arrangement makes a Digital Buffer.

Figure 5: The NAND and NOR equivalents using logic NOT gates

Construction of Logic NOT Function

The logic NOT function is extensively used in digital circuits and is available in dedicated IC packages having multiple logic NOT gates. However, the logic NOT function can also be constructed using NAND or NOR gates as they are Universal Gates. The construction of logic NOT using NAND or NOR gates saves the space and cost of using separate logic NOT gate IC package. The following figure shows NOT function equivalents

Figure 6: The logic NOT function using NAND and NOR gates

Commercially Available Logic NOT Gates

The logic NOT gate is available in form of an I.C. package that contains multiple NOT gates. The I.C. packages come in both Transistor-Transistor Logic (TTL) and Complementary Metal Oxide Semiconductor (CMOS) families. A few commercially available logic NOT gates are given below:

TTL 74LS04 He NOT Gates
CMOS 4049 Hex NOT Gates
CMOS 4069 Hex NOT Gates

Conclusion

The logic NOT function inverts or complements the input signal. It outputs FALSE when input is TRUE and TRUE when input is FALSE.
The logic NOT gate is also called an “Inverter” because of its inverter function.
The logic NOT gate is used in the construction of Universal Logic gates such as NAND and NOR gates.
The logic NOT function can be implemented in digital circuits using NAND or NOR gates which eliminates the use of a dedicated logic NOT gate IC package.
The logic NOT gate is available in different TTL and CMOS IC packages.

Murata’s 32.768 kHz MEMS SMD Resonator

Posted on 12 November, 2021 by mixos

Murata’s MEMS SMD Resonator features an innovative, space-saving design with built-in load capacitors.

Murata’s MEMS resonators achieve excellent frequency, accuracy, and stable temperature characteristics without the use of active elements to correct the initial frequency and frequency shift by temperature. MEMS technology was implemented into this ultra-small resonator with very low ESR characteristics that are currently unachievable by quartz crystal resonators. This helps users reduce both power consumption and mounting space.

The device supports high-reliability, especially in high-temperature conditions, because it does not utilize organic adhesives inside of the package. For this reason, this device can be used in applications where good high-temperature performance is required, such as in industrial equipment and lighting.

The ultra-compact chip-scale package (CSP) incorporates the necessary load capacitance for the oscillation circuit. This enables a reduction in the total space used for the oscillation circuit, which reduces overall board size and costs.

Features

High reliability under high temperatures
Space-saving design (0.9 mm x 0.6 mm)
Ideal for embedding into ICs
Low power consumption

more information: https://www.murata.com/en-global/products/productdetail?partno=WMRAG32K76CS2C00R0