Fixing switch bounce in firmware

I have been involved in many products where a poor understanding of switch bounce has led to a design that had problems in the field. To learn how to deal with this the engineer has to understand exactly what switch bounce is. Although I refer to this as switch bounce, it relates to reading any input.

Custard Pi 8 project for the Raspberry Pi - Electronic Dice

This project is ideal for schools and colleges to demonstrate using the Raspberry Pi in an electronics project. It uses the GPIO and also can be used to teach students to solder conventional and SMT devices as well as wires.

Custom metal enclosures for products - an alternative to injection moulding

Many designers rush to injection moulding when designing enclosures for electronic products. Often there are many other alternative options. Here we consider custom metal enclosures with a case study  using the PAT-IT Portable Appliance Tester. More examples can be seen in the book "From Prototype to Product - a Practical Guide for Electronic Engineers".

Weighing scales project using a Load Cell and Custard Pi 3

This is an experimental project using a Load Cell and the Custard pi 3 to produce weighing scales. A circuit to amplify the signal and sample code is also presented.

Custard Pi 7 - Hardware Hackers interface to the Raspberry Pi

This post presents information about the Custard Pi 7. This has relay and open collector outputs, 8 bit general purpose pins that can be programmed as inputs and outputs, 4 analogue inputs and 1 analogue output and an LCD interface. It also has a prototyping area which icludes layout for a SMT IC. All of this is provided using the I2C interface which leaves all the rest of the pins on the GPIO to be used for other purposes if required.

Custard Pi 6 8 Relay Card for the Raspberry Pi

This post describes the Custard Pi 6 circuit. It shows users how to customise this PCB assembly for different purposes. For example, the board can be fitted with fewer relays to save cost or supplied from a single 5V supply.

Electromagnetic Compatibility (EMC) - a brief for electronic engineers

All electronics engineers involved in product development should have an appreciation of EMC. Many product designs have hit problems due to an inadequate understanding of this. The most recent example of this was the delay to the launch of the Raspberry Pi in 2012. The product launch was delayed for many months while all the required EMC testing was carried out.

(This is a chapter from the book "From Prototype to Product". For more information or to buy the book, follow the link.)