Stage 3/6: Creating a Freader Hub

Now that you’ve finished building a Freader you can begin creating a Freader Hub. This should take 1 hour or less.

This step is concerned with the all-important central hub that collects and stores data from the individual Freaders. It’s built from a Raspberry Pi 3A+ which is a mini computer that acts as a programmer and WiFi server. A system can consist of one or many Freaders, but every system will need the Raspberry Pi based hub (the Freader Hub) to collect readings from the Freaders. Creating the hub involves downloading custom software from our server and then mainly plugging components together in a precise way.

* The cost of power banks vary enormously, so do shop around. In addition, the capacity of the battery depends on how long you wish to leave your Freader Hub running. Some users are happy with 2 or 3 hours of usage from a pound-shop battery, while others prefer that the battery lasts over a day - so finding the right balance may take some experimentation.

Instructions

3.1 Make sure you’ve got everything by laying it all out on the printable sheet provided here.

The next 4 steps (3.2 - 3.6) Involve copying the camera software to a micro SD card (up to 1 hour). This software contains the operating system for the Raspberry Pi 3A+ and everything needed for setting up and running individual Freaders. This bundled software is often referred to as a ‘disk image’.​

Downloading the software and installing it on the SD card can take a while, depending on things like the speed of your internet and the computer you’re using. ​

3.2 Download the disk image (a *.* GB file) from the following link (up to *hour download depending on the speed of your connection):

http://interaction.gold.ac.uk/freaderhub.img.zip

3.3 Take note of the location where the disk image is being saved on your computer. ​

3.4 Download an application called ‘Etcher’. This will copy the disk image to the micro SD card safely and easily (note: Etcher refers to the process of copying the disk image as 'flashing the drive'). ​

3.5  Insert the Micro SD card into your computer - using a micro SD adaptor* (your laptop may have a built-in SD card reader) or an external micro SD reader​.

* When using a micro SD adaptor, be sure that the copy protection switch is unlocked.

3.6 Using the ‘Etcher’ software - select the  disk image as ‘Image’ and the micro SD card as ‘Drive’, then press ‘Flash’. This step takes around 15 minutes.

Note: After Etcher has 'flashed the drive', Windows based computers will sometimes ask if you would like to format the SD card. If this happens, click 'no', otherwise the software will be deleted. ​

3.7 Insert the Micro SD Card into the Raspberry Pi 3A+.

3.8 Insert the CR1220 button battery into the RTC module. The ‘+’ side of the Battery should match the ‘+’ side on the RTC module.

3.9 Plug the RTC module into the end of header pins on the Raspberry Pi 3A+ as shown above.

3.10 Plug the larger end (USB-A) of the USB Cable into the Raspberry Pi 3A+ USB port.

3.11 Plug the smaller end (mini-USB) of the USB Cable into the Serial Programmer.

3.12 Join the Serial Programmer to the Freader Board with Jumper Cables by linking the 6 pins on the Serial Programmer to 6 pins on the Ada Fruit Huzzah Circuit Board. Connect the cables in the orientation shown. You should match the pin labelled GND on the Serial adapter to the pin labelled GND on the blue board.

Note: Here we show the Freader Board dismounted from the Bird Feeder and Freader Coil Assembly created in Stage 2. You have the option to do it this way as shown, or to continue these steps with the Freader Board attached to the Freader Coil and the Bird Feeder.

3.13 Finally power the Raspberry Pi 3A+ by plugging the Mini USB port to a 5V power source. You can do this by using a mains power adaptor or a portable USB Battery.

3.14 Your Raspberry Pi 3A+ has now become your Freader Hub. Please leave the assembly running like this in preparation for the next step.

You’ve now completed Stage 3/6 ‘Creating a Freader Hub’. When you’re ready please move onto Stage 4/6 ‘Registering a Freader with the Freader Hub’.