A few months back, I bought myself a cheap SR04 ultrasonic rangefinder (Datasheet: http://goo.gl/LBZeDG), as per off the magical eBay (Example – Link will expire: http://goo.gl/h9j79O). 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 […]
Well in light of my recent hardware addition, I’ve decided to convert the basis of my HD44780 code into a standalone library. I’ve also added the ability to print signed integer numbers with padding with my whole code including examples compiling to < 3.5k at O0 optimization! Snazzy or what, with O3 optimization, I’ve managed […]
And voila! As I said in one of the last two posts (Initial post: https://hsel.co.uk/2014/08/14/stm32f0-discovery-board-and-the-hd44780-lcd/ and integrating a charge pump for backlight control: https://hsel.co.uk/2014/08/14/stm32f0-discovery-board-with-hd44780-and-integrated-charge-pump/), 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 […]
The HD44780 requires a large voltage difference between Vcc and Vo to get a good contrast on the screen. When running at 5v, this difference can be pretty pretty easily achieved by merely putting a resistor between Vo and ground, dropping a certain voltage across it. However, when running at 3v, this voltage difference isn’t […]
As with nearly all of my posts, this one too starts with a really cheap eBay buy (£1.25, example: http://goo.gl/oLn3pG – Link will expire!). The HD44780 LCD (Datasheet: http://goo.gl/zQDnLh) is a pretty versatile component supporting 16 characters and 2 rows, implementing some cool functions like display shift and text scrolling. It uses an 8bit or […]
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: https://hsel.co.uk/2014/05/29/hmc5883l-magnetometer/). I’m really not a fan of the I2C implementation on the STM32F0 discovery board as many things don’t seem particularly apparent at […]
Well! I’ve been looking to further develop my VGA controller on my CPLD. So as per, I’ve been researching into methods and what not and found out that 800×600 at a refresh rate of 72Hz uses a standard pixel clock of 50MHz! This is obviously in comparison to many other VGA modes which seem to […]
As mentioned in the previous post (https://hsel.co.uk/2014/08/08/designing-a-trianglesquare-wave-vco-part-1/), the maths and somewhat lesser interesting theory will be discussed in this post! Now just as a disclaimer: I’ve just completed my first year of university and we do cover the shockley equation, we don’t however cover lambert W function and I don’t want to use an interative matlab […]
Its rare that I ever really dabble in any form of analog circuit design nowadays but I was a bit bored at work during my break and decided that it’d be fun to try and make a triangle/square wave VCO. I’ve been studying a lot about PLL’s lately and VCO’s are extremely important in the […]
Yes! Today, the big moment arrived any my sexy ass piece of Phobass (MDF) arrived! I’ve never dabbled in 3d design in my life but with the help of a willing manufacturer and a bit of time to learn how to use Inkscape, I managed to do a full design for a fairly good price! […]
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