Monday, 24 February 2014

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".

Tuesday, 18 February 2014

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.

Monday, 16 December 2013

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.

Wednesday, 20 November 2013

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.

Monday, 7 October 2013

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.) 

Monday, 30 September 2013

From Prototype to Product - book aimed at graduate electronic engineers

Electronic product development is a specialist field. It requires not only a good understanding of the technology - it demands a thorough knowledge of the whole process of taking an electronic design through the various stages and making it available for sale. 

Sunday, 14 July 2013

Using functions in Python to control the Custard Pi 6 relay card for the Raspberry Pi

Having designed an 8 relay card for the Raspberry Pi using the IIC bus, I had to come up with a way of testing this and providing users with a way of easily using this. I am not a programmer - but as an electronics engineer I have had to work alongside programmers and even had to make minor modifications to programs. This post describes my experiences with this project using the MCP23008.