STM32F0 – Software capacitive touch

Capacitive touch is “rad”. By utilizing one of the simplest physical characteristics of an object – charge storage, one is able to measure the presence of a grounded object including touch and pressure. There are a couple of capacitive touch libraries that I’ve seen around but many require dedicated hardware, for example the TSC peripheral […]

Eon Ultra – It livessss!

Wahooo! After a lovely christmas visit from the girlfriend, I can get round to applying my new postal arrivals – some 680nF capacitors, some 100nF capacitors and some 10M resistors; the last few items required to get the LCD working. Full backlight brightness with status LED’s in saw and triangle modes. All that is left […]

Designing a 555 timer wannabe

As I’ve previously said I’m not actually very good at analog design – due to a mixture of not really being taught past the basics and maths not being my strong point! Nonetheless, I enjoy doing it and when the circuits I design work as I intend, its a great feeling of achievement, much more […]

Interfacing the HC-SR04 ultrasonic distance sensor and the STM32F0 Discovery board!

A few months back, I bought myself a cheap SR04 ultrasonic rangefinder (Datasheet:, as per off the magical eBay (Example – Link will expire: As you can imagine, these things are ridiculously cheap at a mere 99p inc. p+p. How that is even profitable, I’ll never know! They’re actually pretty nice devices and allow for […]

HD44780 LCD with PWM LED Backlight control

And voila! As I said in one of the last two posts (Initial post: and integrating a charge pump for backlight control:, I’ve now included a generic LED backlight PWM controller using one of the standard GPIO pins. I’m using GPIOA Pin 6 to drive the LED backlight and I’ve integrated a 4bit (16 step) backlight […]

STM32F0 Mini tutorial – Using the I2C peripheral to communicate with a HMC5883L digital compass IC

Well! I’ve had a fair few requests in the past few weeks about how I got the HMC5883L digital compass IC working with my STM32F0 discovery board (as shown in a previous post: I’m really not a fan of the I2C implementation on the STM32F0 discovery board as many things don’t seem particularly apparent at […]