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.
Tuesday, 14 March 2017
Monday, 26 December 2016
Tuesday, 19 July 2016
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
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
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 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
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.