FlappyDuino – Arduino Day 2014 celebration

March 29 2014 is Arduino’s 10 years birthday, also the World’s Arduino Day. In conjunction with the global celebration, SG Makers in partnership with IDA is organizing a whole series of events for Singapore Arduino lovers. And I was invited to showcase some Arduino projects. Continue reading “FlappyDuino – Arduino Day 2014 celebration”

HOWTO: Write a display driver for SEGGER emWin

One lucky day you wake up to find your dream of creating sophisticated graphics user interface for MCU projects comes true, because STMicroelectronics has released a free version of SEGGER emWin for STM32 line of ARM controllers. But your excitement is quickly balanced by the frustration that your favourite LCD panel is not supported. That is a typical day of mine, and my favourite LCD is a 2.6″ 400×240 IPS panel, model TFT1P5971-E by Truly. This post is about how to make the LCD usable with emWin. Continue reading “HOWTO: Write a display driver for SEGGER emWin”

JTAG adapter for Arduino Micro

For the holiday season I get myself an AVR JTAGICE3. Holding the new shiny emulator and a bunch of Arduino boards, what shall I do? Of course to hop onto the all-hail Atmel Studio and ditch the toy-alike Arduino software. Reason being? Debugging Arduino code with serial console is no fun. I need my single steps, breakpoints and watches back. In fact the Arduino boards seems to be more valuable (to me) without the software. The onboard ISP connector seems to be standard and it “just works” with JTAGICE3. Well, I had this “just works” impression until I tried it on the new Arduino Micro board… Continue reading “JTAG adapter for Arduino Micro”

FT230X charger detection investigation

I bought some FT230X (FT230XS) USB-USART bridge chip recently for a new design.  FT230X is not only cheaper than the traditional FT232RL, but also offers a new fancy “USB charger detection” function. This interests me because I’m quickly running out of desk space and power socket. I wish the new device to be solely powered by USB and/or battery.

Continue reading “FT230X charger detection investigation”

Hacking a cheap LED voltmeter

I’m planning to build a EEVblog-ish constant dummy load for battery and power supply testing. Dave in his build used a LCD voltmeter for the display. In the senseless pursuit of difference, I tried other display solutions including character LCD, graphics LCD, OLED, TFT, AMOLED, IPS, which resulted in several previous blogs but nothing ends up to be satisfactory. Along with the complexity grows exponentially from one  solution to another, I slowly start to feel the importance of KISS concept, keep it simple stupid. All I need is just a number display, nothing fancy, nothing pricey, nothing takes my attention away from the analog circuitry. I decided to go back to the basic 7-segment LED display. “Simplicity is the ultimate sophistication”, how elegant it is! Continue reading “Hacking a cheap LED voltmeter”

Opensource STM32 development

In an upcoming project I need a micro controller that operates: 1x 16-bit DAC (SPI); 1x 24-bit ADC (SPI); 1x 8-bit parallel LCD; 1x rotary encoder; 1x PWM fan; 1x fan tachometer; 1x temperature sensor (DS18B20); 2x analog switches; 1x uplink UART; 4x push buttons, and some voltage monitoring for various power rails. To my estimation these peripherals require about 40 pins. Considering the additional clock, power and programming/debug lines, the minimal pin count I’m going for is 64. So I went to element 14 parametric search to look for a suitable chip.

Continue reading “Opensource STM32 development”

Poorman’s OLED test jig

During last (Chinese) year end shopping frenzy I grabbed some OLED display panels, hoping to boost the presentation of my projects.  The panel model is UG-2864ASGGG14, made by “WiseChip Semiconductor Inc.” in Taiwan. Unlike typical LCD modules with complete interface board and 0.1 inch pitch pin headers,  this is a bare panel comes with only the glass and flex PCB connectors.  Continue reading “Poorman’s OLED test jig”

MF70 CNC PCB milling

During a recent shopping mania I grabbed some old AMOLED screens at very cheap price. The seller is an electronics hobbyist. He is kind enough to provide an adaptor board that generates required bias voltages for the screen. Unfortunately the board uses 2×12 DIL header, pain in the arse for breadboarding. I realize this is a perfect opportunity to test drive my MF70 CNC for PCB milling. So I quickly fire up Eagle and create a DIL to DIP adaptor. Continue reading “MF70 CNC PCB milling”

Saleae Logic PWM generator

In a recent project I need a 3.3V PWM signal generator. Initially I think the fastest  way to do it is using an Arduino and write a simple program with analogWrite() function. But I’m too lazy to setup the breadboard… so I tried google.

Soon I come across a free software called “PWM Logic“. Supposedly it will turn Saleae Logic Analyzer into a PWM generator. An original Saleae Logic is somewhat too steep for my pocket right now. But I do have a cheap Chinese clone lying aroung. So I hook it up. Not surprisingly it does not work. Continue reading “Saleae Logic PWM generator”