Measuring Power Using a Current Clamp

This post shows hot to use a current clamp to measure current and power using an op-amp based rectifier, and A to D and the Raspberry Pi. This is an extract from the e-book on Interfacing the Raspberry Pi to Analogue Signals.

Playing tunes with the Raspberry Pi

This project uses the Raspberry Pi GPIO to generate various musical notes. We are going to get the RPi to play a pre-programmed tune. This is one of 10 projects that can be made with the kit here and e-books is available for the Amazon Kindle here

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.

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.

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.

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.

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.