So for the second year we intend to run the robot as a Wifi access point to allow us to connect via ssh and check/debug Tractor Bot. Phil was a bit concerned that the Pi 3’s radio could not run as an access point however he came across this handy guide and we can now connect either to the Pi as an access point or allow it to connect to any of the Wifi networks it knows about.
It works really well and means that Tractor Bot can be run headless very easily.
Pi supporting two wireless interfaces, one using the internal radio as an access point and one using an external dongle bound to Phil’s router. Not to mention a hard line to the same network.
So we now have all the challenges bar the golf sorted, which Keith is working hard on.
Jon is taking care of the leads required for the final design and Phil is going to be cutting the perspex for the body.
We need a bigger laser and more hours in the day…
Early on in the proceedings Jon had suggested we build a maze full size for testing (along with twin robots). So armed with wood, glue and screws he built a maze and even made it in bits so that it fit in his car! At least one pair of jeans paid the price due to the very foamy Gorilla glue. Anyway his hard work paid off…..
This is completely autonomous using three ToF sensors.
The small OLED display was working well for each challenge, allowing the operator to select the challenge by way of a small graphic menu. This is it in extreme close-up.
Jon designed a bitmap editor to create the mini icons and then we painstakingly joined the dots. You can find the editor here: https://leachj.github.io/OLED_Pixel_editor/
So with a couple of challenges down and a reasonable remote control we were feeling fairly happy then we realised that we had less than a month to go! The Pi Party had taken out some of our development time so we had to press on. Keith got on with designing a catapult for the skittles challenge.
Rapid prototyping meant that one email to Phil containing the DXF’s for the laser cutter and the design was being put together for review that evening.
But we still had the golf challenge to put together something for…..
While there has been lots of cutting and 3D printing to do, Phil had also agreed to code the line follower challenge. With TractorBot I we had experimented with the Open CV computer vision software but the results were disappointing. However, with Pi 3 power we thought we might be able to get a Pi Camera to perform the line following duties at reasonable frame rates. Initial trials were encouraging and Keith designed a servo controlled camera case for the front of TractorBot.
The idea being that when the line follower choice was made from the menu, the servo would activate and the line would be illuminated by a Blinkt in the nose. After a few attempts and a lot of tuning we were happy with the result. https://youtu.be/Yrbg0VhtKmk
This is a graphic (sorry) illustration of how far the Pi has developed in just a few years.