For the Gnome Street Gnome event I wanted to be able to run the workshop without the need for lots of HDMI monitors and keyboards. I also wanted the simplest set-up possible as I knew I'd likely need to do it multiple times. The organiser provided me with a pile of Pi3, each with an SDcard containing noobs.
I used the latest full Raspian image and flashed it to the SDCards using my laptop and Win32DiskImager. The image contains all the software needed pre-installed so saved me downloading more.
The raspberry pi 3 will happily run without a keyboard and monitor but I needed to configure the WiFi adapter before we could connect to them. The easiest way to do this would be to use a keyboard and monitor to do the setup.
As I did not have this, I used the console which can be accessed via a serial connection attached to the TX and RX pins on the Pi's header. I used a USB to TTL module, checking that it was 3.3v compliant. Mine was a CH340 based module and seemed to work fine. I connected TX, RX and GND, and powered the board from a second USB port or supply. Some boards also provide 5v power so check your documentation. On the PC you run a serial terminal such as Putty and connect it to the serial port, you can then access it in the same way you'd do from a command prompt on screen or SSH remotely.
To configure the WiFi I edited the wpa-supplicant config file, I then used the raspi-config tool to change the host name.
Node-red was already installed so it was set to run on boot using:
sudo systemctl enable nodered.service
Finally the boards were rebooted and we ready for use.
To make accessing the node-red designer straightforward, I installed the Bonjour software on the Windows laptop. This allows connection via http://raspberrypi.local:1880 rather than needing to know the IPAddress, this should not be needed if you are accessing via a Mac, Linux PC or tablet. The service part of this capability is already installed in the image.
Whilst researching this, I realised that there's quite a few steps that have been improved over the years which made my job a lot simpler than first thought.
I also tried the Raspian Jessie Lite version, that also works but you will need to install Node-Red and it's dependencies.
It was a good thing that I did not have to install anything during the workshop as the art centre WiFi required you to accept terms and conditions. I only realised this when we tried to play a WAV file of a police siren and all we got was noise. We had downloaded the file directly onto the Pi using WGET. I opened the file to see if it was corrupt and realised it was HTML! We got around this by downloading the files on PC and coping them over using WinSCP.
- Install Raspian on SDcard
- Configure to connect to WiFi
- Set unique host name
- Configure Node-Red to auto start