Posts Tagged ‘electronics’

Build your own Digital Scale with this DIY Kit

December 11th, 2017 4 comments

Electronics DIY kits are easy to find from either Arduino kits, or robotics kits, to oscilloscope kits among others. But I can’t remember ever seeing digital scale kits, maybe because I did not look for it, but that’s exactly what I found on ICstation for $27.99 for scale that can measure weights up to 10 kilograms with a reported one gram accuracy. The DIY scale can also be pruchased on eBay for $29.99.

Main items in the (Trans–CRS–162DZC) kit and features:

  • MCU – STC MCU Limited STC89C52 8-bit (80C51 compatible) MCU in 40-pin DIP package
  • RTC – DS1302 8-pin DIP chip + CR1220 socket and battery
  • EEPROM – AT24C02 serial EEPROM (DIP chip)
  • Display – LCD1602 16×2 digit display
  • Keypad – 4×4 matrix keypad
  • Sensors – DS18B20 one-wire temperature sensor, “C3 high precision” 10kg strain pressure sensor
  • Boards – HX711 load cell amplifier module, printed circuit board for the MCU, RTC, EEPROM, etc…
  • Misc – Buzzer, transistors, various passive components
  • Enclosure and accessories
  • Power Supply – 5V DC
  • Dimensions – 15.2cm x  14.1cm x 6.5cm (assembled)
  • Weight – 500 grams

Follow the assembly guide to build the scale yourself, and you should be good to good to use your own scale/clock/alarm/thermometer toy.The scale could also be the starting point to make your own design either programming the STC89C52 micro-controller with your own program (AFAIK source code is not available so you’d have to start from scratch), or possibly “IoTize” the scale by replacing the MCU by a Bluetooth or WiFi (ESP8266) module.

Categories: Hardware Tags: diy, electronics, sensor

MeanWell Mini Switching Power Supplies May Be Useful for Development Boards

December 11th, 2017 10 comments

While some people or organizations with lots of boards may use high-end USB hubs to power and control them, most people likely use wall adapters to power their development boards like Raspberry Pi 3, ASUS Tinkerboard, Orange Pi PC, and so on.

At least that’s what I do, except in some cases when I suspect power issues, and I go with a more powerful SMPS (switch mode power supply). I don’t use it often because it’s a large brick and expose 220V. But the other day, as I attended Chiang Mai Maker Party, I found one maker uses some tiny (and cute) power supply from a company called Mean Well to power his Raspberry Pi boards.

The model used above with RS-15-5 with takes 100-240VAC 0.35A input, and output 5VDC up to 3A. The power supply include AC Neutral, AC Live, Ground, DC V+ and DC V-  pins where you can insert the wires/cables and fastened them with a screw. You’ll find the complete specifications here. Unless you can put the power supply into an enclosure, this type of power supply may not be recommended if you have young kids running around, in case they fiddle with the mains connections.

The company meant well… when they designed the nomenclature of their power supplies, as the first number stands for the wattage, and the second for voltage. So for example, if you want a 25W power supply with 5V output, you ‘ll find RS-25-5 model. In the datasheet linked above, they have 15W power supplies from 3.3V to 48V.

RS-15-5 power supply pictured above can be purchased for $8 on Amazon US, and plenty of sellers offer it on Aliexpress or eBay. More models can be found on their website.

Sigrok Compatible ZeroPlus Logic Cube LAP-C USB Logic Analyzers Support up to 32 Channels, 75 MHz Bandwidth

December 4th, 2017 1 comment

Back in 2015, I discovered USB123 USBee AX PRO, an ultra cheap logic analyzer (now $5 shipped) with 8 channels, and up to 24 MHz. I purchased one at the time, and successfully tested it with Sigrok & Pulseview open source tools that now work in Linux, Windows, Mac OS, FreeBSD, Android, and several other operating systems.

As I read through my list of RSS feeds today, I noticed Peter Scargill had tested ZeroPlus Logic Cube Lap-C 322000 logic analyzer also connected to your PC via USB, but with better specifications including 32-channels, and 75 MHz. Peter used the company’s Windows software (ZEROPLUS Logic Analyzer LAP-C_Standard_V3.14.03), but a quick search confirmed ZeroPlus Logic Cube Lap-C family is supported by Sigrok.

Click to Enlarge

LAP-C 322000 is the top model from the family with the following hardware specifications:

  • Sample Rate – Internal clock (timing mode): 100Hz~200MHz; external clock (state mode): 100MHz
  • Bandwidth – 75MHz
  • Working Range – -6V~+6V
  • Accuracy – ±0.1V
  • Memory – 64Mbit, i.e. 2Mbit per channel with up to 512Mbits with compression enabled
  • Trigger – Condition: Pattern/Edge; 32 channels; trigger count: 1~65535
  • Phase Errors: < 1.5ns
  • Maximum Input Voltage: ±30V
  • Impedance:500KΩ/10pF
  • Power Supply – 5V/500mA via USB port
  • Safety Certification – FCC / CE / WEEE / RoHS / REACH

Click to Enlarge

The hardware is based on ZEROPLUS ZP-322MB-5 which is believed to be a custom ASIC from the company, Genesys Logic GL660USB (USB2.0 to IEEE-1284 / DMA bridge), Cypress SRAM, and various other chips as explained in the sigrok page.

The company’s software supports Windows 2000 to Windows 10 with plenty of features (Waveform display, filter, filter delay, trigger delay, protocol analysis, etc..), and you can read a detailed review of the device used with the Windows software if you are interested. If you prefer open source software, or run another operating system Sigrok should be a worthwhile alternative.

ZeroPlus Logic Cube LAP-C 322000 is not a low cost part as it goes for $1,599 on Amazon, but other models with the same 75MHz bandwidth, only 16-channels, a lower clock speed (up to 100 MHz), and less memory (512Kbits) such as Zeroplus LAP-C 16032 can be purchased for about $135 on Amazon or eBay. More details should be available on ZeroPlus website.

Detect Lightning with Those AMS AS3935 “Thunder” Boards

November 24th, 2017 1 comment

Launched in 2012, AMS AS3935 Franklin lightning sensor  is – at its name implies – a lightning sensing IC. The chip was designed for low power, portable or fixed wire-line applications, and beside detecting electrical emissions from lightning activity, it can also provide an estimation of the distance to the head of the storm from 40km away down to 1km, while filtering out other signals from motors, microwave ovens, etc…

Click to Enlarge

The chip interfaces via SPI or I2C to the host processor / micro-controller, and comes in a small MLPW-16 (4x4mm) package. Price is $3.55 per unit for 1k orders. Applications include wearables, golf carts, pool safety, portable GPS, bike computers, weather stations, uninterruptible power supplies, smart grid systems, environmental monitoring systems, etc… Basically, AS3935 can be used either for weather monitoring, or safety applications.

I’ve found two maker boards with the chip: MikroElectronika Thunder Click board compatible with MikroBUS socket (available now), and SwitchDoc Labs Thunder Board recently launched on Kickstarter, but that may be easier to use since Raspberry Pi and Arduino kits are offered.

MikroElectronika Thunder Click Board


  • On-board modules – AS3935 lightning sensor IC; MA5532 coil antenna
  • Detection – Distance to the head of the storm from 40 km down to 1 km in 14 steps; Detects both cloud-to-ground and intra-cloud (cloud-to-cloud) flashes
  • I/Os –  GPIOs, and SPI
  • Supply Voltage – 3.3V or 5V
  • mikroBUS socket compatible
  • Dimensions – 42.9 x 25.4 mm

You’ll find documentation and examples on the product page, where you can also purchase it for $35.  The board is ideal if you own a board with a mikroBus socket such as Hummingboard Gate, or Microchip Curiosity, although MikroElectronika sells MikroBus adapters for Arduino and Raspberry Pi boards. Note that the sample are for Microchip PIC32, so you’d have to adapt the code to your own platform.

SwitchDoc Labs Thunder Board and Kits

Specifications are basically the same as for Thunder Click boards, except it exposes two Grove connectors for Seeed Studio modules, and it interfaces to the host processor via I2C instead of SPI, and include 3 I/Os for interrupt and 2 analog inputs on the header.

But if you want something really easy to get started, the IoT Kits for Arduino or Raspberry Pi Zero W are the way to go. They are plug-and-play with an LCD display showing lightning info and a buzzer sound the alarm when lightning is detected, customizable thanks to open source software, and can be connected to the Internet over WiFi.

The Arduino kit includes:

  • The Thunder Board
  • Grove Mini Pro LP Arduino @ 16MHz
  • Grove WiFi Interface, LCD Display, and Buzzer
  • Grove cables
  • USB cable for power
  • FTDI cable for Programming
  • 3D printed enclosure or files depending on selected perk

The Raspberry pi kit includes:

  • The Thunder Board
  • Grove Temperature and Humidity Sensor, LCD Display, and Buzzer
  • Pi2Grover for Raspberry Pi
  • Grove Cables
  • 3D printed case or files  depending on reward

You’ll need to add your own Raspberry Pi board to the second kit, preferably Raspberry Pi Zero W.

The kits can transmit data to Pubnub over MQTT, which then displayed on Freeboard Internet dashboard as shown below.

Since lightning only occurs during thunderstorms, it would make testing problematic, or at least very slow, if you just had to wait for natural occurrences. So the company also made the Thunder Lightning Simulator board based on Arduino.

The Kickstarter campaign has already surpassed it funding target with over  $5,000 raised, and 12 days to go. A pledge of $23 should get your the Thunder Board, a $75 pledge is asked for respectively the Arduino and Raspberry Pi kits with 3D printed file, while $170 is needed if you want a complete Arduino kit with case and simulator. Shipping adds $3 to $30 depending on rewards and destination. Delivery is scheduled for next month.

Hantek PSO2020 is a $53 USB Oscilloscope Pen

September 15th, 2017 2 comments

I previously covered IkaScope & Aeroscope oscilloscope probes that are both portable and connect wirelessly to your mobile device or computer over respectively WiFi or Bluetooth. The former has slightly better specifications and sells for 300 Euros, while the latter goes for $200 US with 20 MHz bandwidth and 100 MSps capabilities. Several people mentioned it was more expensive than they were prepare to pay, but I’ve been informed about another portable solution: Hantek PSO2020 oscilloscope pen with about the same key specifications as Aeroscope 100A, except it relies on a USB port instead of a wireless connection. This also means it does not need a battery, and sells for much less at $53.20 including shipping.

Hantek PSO2020 specifications:

  • Analog Bandwidth  – 20 MHz
  • Sample Rate – 96 MSps
  • Host Interface – USB 2.0 port
  • Input Range – +/-50 V range
  • Input Sensitivity – 20mV/div to 50V/div
  • Offset Range – +/- 20V to +/- 40V offset
  • Input Impedance – 1MΩ
  • Voltage Resolution – 20mV/div to 20V/div
  • Sample Resolution – 8-bit
  • Time Resolution –  1ns/div to 5000s/div
  • Memory Depth – 1 million points
  • Protection Input Level – 100V (DC+AC peak)
  • Misc – Rotary button to change voltage/time division; voltage, offset, position, time, plus, minus, and R/S buttons; LED
  • Dimensions – N/A

The oscilloscope ships with a “witch hat”, and a CD ROM with documentation and software that works on Windows XP and greater operating system, and supports various features including math functions like FFT or Hann function, cursor measurements, and so on. You can also download those directly from the manufacturer’s product page. The device is not listed in Sigrok wiki, but other Hantek USB oscillopes are, so it might be possible to use with Sigrok open source tool. The pen has been available at least since 2015, but I could not find any (detailed) independent reviews, however the video below shows how PSO2020 in action while connected to a laptop running the Windows based tool.

It’s fairly large so I’m not sure it’s that convenient to use. Having said that people who bought it on Aliexpress appear to be pretty happy with their purchase. The few “reviews” left on Banggood are also good.

Thanks to Theguyuk for the tip

IkaScope WiFi Oscilloscope Probe Works with Windows, Linux, Mac OS X, Android and iOS

September 13th, 2017 11 comments

Last year, I wrote about Aeroscope, a portable Bluetooth oscilloscope that looks somewhat like a Stabilo Boss highlighter pen, and sends measurements over the air directly to your Android and iOS tablet or smartphone. It was introduced through a crowdfunding campaign which eventually failed, but Aeroscope can now be purchased for $199 on Amazon US or their own website. If you’d prefer WiFi over Bluetooth, and would like something that also works on Windows, Linux, and/or Mac OS X, IKALOGIC has just launched IkaScope WiFi oscilloscope probe compatible with all popular mobile and desktop operating systems.

IkaScope WS200 specifications:

  • Analog Bandwidth  – 30 MHz @ -3dB
  • Sample Rate – 200 MSps
  • Connectivity – 802.11 b/g/n/e/i WiFi @ 2.4 GHz configurable as access point or station
  • Input Range – +/-40 V range CAT1
  • Offset Range – +/- 20V to +/- 40V offset
  • Input Impedance – 10MΩ || 14pF
  • Input Contact – ProbeClick intelligent probe tip that will only start measurements upon contact
  • Voltage Resolution – 100 mV/division to 10 V/division
  • Sample Resolution – 8-bit
  • Max Refresh Rate – 250 fps
  • Memory Depth – 4K points (4x 1000 points for burst buffers)
  • Protection Input Level – 253 VAC 1min
  • USB – Isolated micro USB port for charging only
  • Misc – Power/Charging and WiFi status LEDs
  • Battery – 420 mAh battery good for about 1 week battery life with daily regular use.
  • Dimensions – 161mm long

IkaScope specifications are slightly better than the ones of Aeroscope when it comes with analog bandwidth and sample rate for example, but the battery capacity is lower. However,  the latter is likely more than compensated by ProbeClick technology that will only measure when a contact is detected, hence saving power during idle times. One advantage of WiFi over Bluetooth is that it allows for a higher refresh rate up to 250 fps.

The probe ships with a ground clip and a USB charging cable. OS support will be brought step by step starting with Windows, but Linux, Mac OS X, iOS, and Android will all be supported by November 9th if the schedule’s deadlines can be met, and all desktop OK will be supported by the end of September before shipping. More details about the software can be found in IkaScope knowledge base.

IKALOGIC has started taking pre-order for IkaScope for 299 Euros excluding VAT and shipping scheduled by the end of the year. “EARLYBIRD” coupon valid until the 20th of September will power the price by 10%.. Some more information, and the purchase link are available on the product page.

HTTM Backlit Capacitive Touch Switch / Button Sells for about one Dollar

July 27th, 2017 1 comment

You may have some project that requires buttons to turn on and off devices, or perform other tasks like navigating a user interface or playing games. One interesting and inexpensive solution for this could be HTTM (HelTec Touch Model) capacitive touch buttons that include three pins for power, ground, and the button status, as well as a backlight. You’ll find them on many websites, and one of the cheapest option is a pack of 10 buttons going for $9.91 on Aliexpress.

HTTM button specifications:

  • Voltage input range: + 2.7v to + 6v
  • Signal output – Voltage: + 3.3v; Current up to 500 mA
  • Header – 3-pin with GND, VCC, and OUT
  • Backlight color – red, blue (cyan), or yellow
  • Dimensions – 20.4 x 16.6 mm
  • Operating temperature range: -30 ℃ to + 70 ℃

You’ll find more details on the manufacturer’s product page including a user manual (Chinese only), and their DIYtrade page implies they may have versions with up to four keys:

HTTM is HelTec Touch Model shorthand;
□ → Number of keys: S- single key, D- double keys, T- triple keys, F- four keys;
◇ → Version attribute: C- conventional version, S- Special Edition (customized version);
△ → backlight colors: B- blue, R- red, G- green

But I could not find any of those. The company (Chengdu HelTec Automation Electronics Technology Co. Ltd) also makes some OLED displays, which may be worth checking out.

I learned about HTTM button via Pete Scargill’s blog, and he shot a video showing how to use the switch directly connected to a relay board (The demo starts at the 1:50 mark). Since it’s using capacitive touch, he explains you could place one or more buttons inside a box, and it would still work. Those buttons are also likely more durable than mechanical switches.

TinyLIDAR is a $15 LIDAR MCU Board based on STMicro VL53L0X Time-of-Flight Ranging Sensor (Crowdfunding)

July 23rd, 2017 4 comments

LIDAR (Light Detection and Ranging) technology is used in autonomous car, drones, and some smartphones, in order to get an object position just like RADAR systems, but instead of using radio frequencies, it relies on infrared signals. High speed, long range LIDAR systems can cost several hundred dollars, but if you’d like to experiment with the technology, or your project would work just fine with 60 Hz scanning and a 2 meter range, tinyLIDAR could be a fun board to play with using Arduino compatible boards.

TinyLIDAR specifications and features:

  • LIDAR Sensor
    • ST VL53L0X Time-of-Flight (ToF) ranging sensor
    • 940nm laser VCSEL
    • Up to 2 meters range
    • Up to 60 Hz sampling rate even with Arduino UNO board
    • Up to 3% accuracy with mm precision
  • MCU – Unnamed dedicated 32-bit MCU (likely STM32) used to abstract the ST PAL API into simple I2C commands
  • Host Interface – 4-pin I2C header; re-configurable I2C address and operation modes
  • Misc – Blue LED, low profile reset button
  • Power Supply – +3 to +5V
  • Power Consumption – 10uA typ. Quiescent Current in single step mode
  • Dimensions –  25 x 21 mm (2x M2 mounting holes)
  • Weight – <1.5 g

Some of they advantage of the board against competing solution include lower power consumption, higher sampling rate (up to 60Hz), as well as lower memory and code footprints with 2604 bytes of program storage space and 252 bytes RAM with distance reading sketch in Arduino UNO compared to  6480 bytes / 414 bytes using Pololu VL53L0X library with a generic VL53L0X sensor board ($14) thanks the MCU in the board. They also claim the board is simpler to use thanks to their I2C command set. The company only showed 3D rendering of the board, but they do have working samples, as showed in the demo below with instructions available in

The Arrow Electronics certified project launched on Indiegogo with a $3,000 funding target. A $15 pledge will get you one tiny LIDAR, but you may as well as commit to three boards for $39. Shipping adds $5, and delivery is scheduled for October 2017. If you’d like to get such solution earlier, without built-in MCU and the advantages it brings, beside the $14 Polulu module linked above, you’ll also find a VL53L0X board working within  2.6 V to 5.5 V range on Aliexpress for $8.92 shipped.