Tuesday, 19 July 2016

Watchdog Timer for the Raspberry Pi

Like all PCs the Raspberry Pi is likley to hang up during operation. In an unattended application where the program automatically starts this can be a problem as there is no one around to restart the RPi. If there is no keyboard or HDMI monitor this is by power cycling. The Raspberry Pis internal watchdog timer has a poor reputaion - there are many comments about it being unreliable. This post presents a simple external watchdog timer.

Monday, 25 April 2016

Upto 64 programmable digital I/O for the Raspberry Pi

The newly launched Custard Pi 4 provides 8 digital I/O per board. Each board can be set to one of 8 seperate I2C addresses. When you use 8 Custard Pi 4s you can get upto 64 digital I/O with each pin individually programmable as an input or an output.

Tuesday, 12 January 2016

Remote Mains Switch with >100m range

I wanted the capability to switch a flood light fitted outside the garage from the Raspberry Pi. With the Raspberry Pi connected to the internet this would give me the ability to remotely switch this light on from anywhere in the world. I had a look at wi-fi enabled power sockets but none of them had the range I was looking for. This project shows how to use the Dual Remote Relay Tx & Rx to do this as this has a range well in excess of 100 metres.

Friday, 27 November 2015

Remote Controlled Dual Relays using FM Radio Modules

Remote control of pumps, heaters, lights and other appliances is often a requirement in Home Automation, Building Control or Automation of Industrial Control processes. Traditional radio modules can often disappoint by having poor range or being prone to interference. FM Radio Modules when compared to much cheaper AM modules gives superior performance in both these areas. This post is about a remote module that has two independent relays for remote switching ON and OFF of appliances.

Monday, 19 October 2015

Remote Temperature Monitoring

This post shows how to use the Dual Analogue Radio Transmitter (DART) and the Universal Radio Receiver (URR) to monitor the temperature of one or more freezer.

Thursday, 8 October 2015

Using the Dual Analogue Radio Transmitter (DART) and Universal Radio Receiver (URR) for Home Automation

When putting together a Home Automation System together it is often necessary to gather analogue data. This could be from temperature / humidity sensors or to measure battery voltage. Often these are remote to the computing module which could be a Raspberry Pi, and Arduino or a PC - for example when gathering data from a weather station on the roof of a building. 

Tuesday, 7 July 2015

Connect 2 Custard Pi 3's to a Raspberry Pi and get 16 analogue inputs

The Custard Pi 3 plugs into the Raspberry Pi GPIO (A, B, B+ and 2) and provides 8 analogue inputs using the SPI bus. This post shows how you can connect 2 x Custard Pi 3 to a Raspberry Pi and get 16 inputs. (There is soldering required).