Monthly Archives: February 2021

A simple VCO (voltage controlled oscillator) for audio

It is possible to generate square waves suitable for audio output using a battery, Schmitt Inverter, capacitor, small speaker, and resistor. A highly recommended option is to use an OPAMP to boost the signal. Here’s a video demonstration: I’m actually … Continue reading

Posted in Uncategorized | Leave a comment

#RaspberryPi bare metal: progress on Terrible Allocation Table

So, I’ve got the SD card working on a Pi 0 bare metal. Cool. FAT32 is a bit trickier. I found someone’s project, but I couldn’t get it to work. So I was pondering whether to try to fix it, … Continue reading

Posted in Uncategorized | Leave a comment

#RaspberryPi 0: PWM hard-coded bare metal audio working

I’ve been experimenting with PWM on the RaspberryPi again. I managed to get a hard-coded sample working, which you can view here. This is pretty cool, because my rough-around-the-edges bare-metal “unikernel”, Crunky, is showing its usefulness to me. Porting the … Continue reading

Posted in Uncategorized | Leave a comment

#RaspberryPi Pico I2C SSD1306 OLED display updated

Thanks to a pull request from Joe Jackson, an example bitmap display is given for my Pico SSD1306 OLED 128×64 and 128×32 I2C display (see here). My code isn’t perfect, but at least it works. You can do bitmaps and … Continue reading

Posted in Uncategorized | 3 Comments

#RaspberryPi Pico: A piano “synthesiser”

After having made an atrocious synthesiser, I thought it would be good to up my game and create a slightly less atrocious synthesiser. This time, instead of using the serial port, I thought I’d actually make a synthesiser. It is … Continue reading

Posted in Uncategorized | Leave a comment

Inside C++ is a Turing Incomplete language waiting to get out

OK, I lied. I’m just clickbaiting. It ain’t waiting for that. But I have something to say about the concept … There’s an esolong (esoteric programming language) out there named something like “Froogle”. That’s not it’s name, but it’s something … Continue reading

Posted in Uncategorized | Leave a comment

#RaspberryPi0 bare metal C++ (mostly working)

I’ve been able to get my Crunky “unikernel” to compile C++. It has stdlib working (string, vectors, etc), class initialisation, and so forth. The big sticking point is exceptions. You can throw exceptions, but it will cause a crash. Linking … Continue reading

Posted in Uncategorized | Leave a comment

IG Holdings

A few days ago IG stated that it is having service difficulties due to an unprecedented high volume of trades and new accounts. Something to do with Gamestop and another company, I figure. I have an IG account, and trade … Continue reading

Posted in Uncategorized | Leave a comment

Creating an poor man’s Schmitt trigger inverter and oscillator circuit using a #RaspberryPi Pico

In my “#RaspberryPi Pico – let’s make an atrocious synthesiser“, I said that I wasn’t particularly happy with the results. The ADC readings were prone to significant fluctuations. I’ve asked about it on the Pi Forums, and apparently that’s to be … Continue reading

Posted in Uncategorized | Leave a comment