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‘iCard’ iPad video recording stand

At work recently we used a number of iPads to record student presentations for exam moderation purposes but there was an issue with holding the iPads correctly to film. All the cases seem to hold the screen slightly tilted – great for watching videos but rubbish for filming something happening directly in front of the [...] Read more – ‘‘iCard’ iPad video recording stand’.

Digital Clock: Adjustments to the Timekeeper Board

The first spin of the timekeeper PCBs was reasonably successful. There were a a few stupid mistakes – for example the 5v regulator output was not actually connected to the 5v supplying the rest of the circuit (no power!) and the carry-in/out pins on the separate timer sections were inadvertently connected to VCC rather than [...] Read more – ‘Digital Clock: Adjustments to the Timekeeper Board’.

Digital Clock: Timekeeper

I’m building a clock from 4000 series logic ICs – the likes of 4081s, 4029s and 4060s, amongst others. The device is split up into boards that handle different aspects of the clock. This is due to the board size limitations of Eagle, something I always find myself fighting with (KiCad is not an option [...] Read more – ‘Digital Clock: Timekeeper’.

Recording audio from a stethoscope

As part of my job at a medical school here in the UK I have to create short videos to demonstrate simple clinical procedures such as cannulation, checking blood glucose levels and taking a patient’s blood pressure the manual way – that is with an inflatable cuff and a stethoscope instead of one of the [...] Read more – ‘Recording audio from a stethoscope’.

Parsing simple USART commands

There’s code available for this article. Colin Brosseau forked this code, made it better and then combined it with Peter Fleury’s UART library – it is more portable and can be used on other microcontrollers. Check it out here. Good job Colin! Due to CameraSpark not having a traditional physical button & screen based user [...] Read more – ‘Parsing simple USART commands’.

Controlling a brushless motor with an ESC and Arduino

For a previous project I was looking at using Electronic Speed Controllers (ESCs) with an Arduino board to provide control of a brushless motor. The ESC is connected to the board via GND and Signal, the +5V is not needed, as the Arduino is getting it’s power from elsewhere. This code allows you to control [...] Read more – ‘Controlling a brushless motor with an ESC and Arduino’.

Counting milliseconds

There is code available for this article The Arduino libraries make use of a handy function to track milliseconds, known as millis(), but looking briefly at the code that makes it up there seems to be a lot of other code intertwined throughout. I want to learn to program AVR devices properly using C, not [...] Read more – ‘Counting milliseconds’.

CameraSpark PCBs have arrived

There are a four mounting holes – one in each corner – for desktop use but it has all been designed to eventually fit perfectly inside a Hammond instrument enclosure, thus explaining the copper free strips down the long edges. Everything on this board has been tested a million and one times on a breadboard [...] Read more – ‘CameraSpark PCBs have arrived’.

MAX7219 and 7-segment displays

There’s code available for this article. The MAX7219 Eagle part is available in the TidyEagle library. Maxim’s MAX7219 and MAX72221 chips are really rather handy when it comes to controlling a collection of 7-segment LED displays. They are also quite useful when it comes to controlling up to 64 individual LEDs when appropriately arranged. The [...] Read more – ‘MAX7219 and 7-segment displays’.

ADHU: Issues 1&2 Fixed

I’ve fixed a few of the niggling issues with AVRDude Hex Uploader and pushed them to the GitHub repository. AVRDude process call is now on it’s own “BackgroundWorker” thread, so the interface doesn’t curl up and die when AVRDude takes a little bit longer than usual. On first run the application should no longer warn [...] Read more – ‘ADHU: Issues 1&2 Fixed’.

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