Driving a LED array from a BeagleBone Black

Over a month ago, now, I had a brief play with my Beaglebone Black. It took me a while but I just about got to the point of flashing an LED. That was enough at the time, but now I want to do something more interesting. So I thought I’d start by doing some patterns …

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Using bit-angle PWM to drive GPIO pins

Although yesterday’s post was a reasonable introduction to bit-angle PWM, showing a pattern of characters on a console screen is hardly the most exciting or useful thing. So today I shall try to use the same code to drive something a bit more fun. I still had the “flowing water light” lying around, which I …

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Efficient software PWM with bit-angle modulation

It is a few months now since I last had a play with pulse-width modulation (PWM). At the time I was concerned by the amount of processing power used by the simplistic approach I had implemented, so I abandoned the exercise. Luckily, there are more efficient ways to do software PWM. One of the most …

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Driving a 7219 LED matrix from a Raspberry Pi

Flushed with my success in getting data displayed on my cheap LED matrix using a Bus Pirate, I decided that the next step was to see if I could get it working with a Raspberry Pi. Looking around for useful resources to get me started I found: Understanding SPI on the Raspberry Pi from Gordon’s …

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Building and testing a Raspi Robot board

I have had a kit of parts for a RaspiRobot board in my “to do pile” for a while now. Today I had a bit of spare time so I followed the construction instructions and put it together. Step one was to check I had the right bits. I opened the packet and laid the …

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Think you know FORTH? then why not enter a competition?

It’s nice to see old favourite programming languages getting a bit of love. “Circuit Cellar” magazine seems to be running a weekly “spot the bug” competition, and this week (week 2) it looks like a bit of FORTH. It doesn’t say much about the program, but it is heavily commented (much more so than most …

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First steps with Beagleboard Black

I have had a few weeks off from electronic tinkering and from posting here, but I’m hoping to ramp up my post schedule again. Today I picked up my new Beaglebone Black. On “paper”, both this and the Cubieboard seem to be serious competitors of the Raspberry Pi. They are around the same price, and …

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Code Warrior, Eclipse, and Freedom boards

As you may recall, I have plans to use a Freescale ARM development board (such as a KL25Z, or a K20D50M) as an I/O interface for at least one Raspberry Pi project. These boards are a bit like a super-Arduino: small enough to fit in the archetypal mint ton, bristling with pins for digital, analog, …

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txtzyme on Raspberry Pi

After my previous post on delimiter-free languages it occurred to me that the idea of txtzyme has merit for communication between some of the devices I have to hand. Some while ago I spent some time producing some bare-metal code examples for the Raspberry Pi (flashing morse code, GPIO control and uart stuff, for example), …

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Delimiter-free languages – bus pirate and txtzyme

A few weeks ago I was experimenting with the clever little “bus pirate” board and its odd control language. A little later I was reading an article about some of the fun things Ward Cunningham has been getting up to with electronics, and I came across “txtzyme.” Thinking further on the similarities between the two …

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