Installing software on the RPi 2 for testing the receivers:
Install node and node-red
$ curl -sL https://deb.nodesource.com/setup | sudo bash –
$ sudo apt-get install -y build-essential python-dev python-rpi.gpio nodejs
$ sudo npm install -g –unsafe-perm node-red
src [http://nodered.org/docs/hardware/raspberrypi.html]
Mainly using node-red in the first instance to test the serial port stuff as it’s so quick and easy. Will end up using python for the final version.
Working out power for all 7 readers:
Tested in the lab with a variable power supply.
each reader uses about 300mAh at 9v (they are usually powered by a 9v alkaline battery)
For 7 I need a 3A 9V plug-in power supply, and can then wire they all together into one source.
Ordered one plus a load of speaker cable to extend the power of each reader.