At long last I managed to get the radio controls for the Mountain Wheelchair to work!
It’s taken so much and time and effort to get this to work. Not wanting to get too technical, I basically needed a way to convert an RC Receiver 1-2milisecond pulse to an analogue 0-5volts. I tried all sorts! In the end I found a very elegant, simple and cost effective solution from an American company called Astro Flight. There were some issues with the shipping but once the item arrived it was a very simple plug-and-play and at last, the mountain wheelchair has a working radio control system.
As I’ve said before, it was extremely important to get this working because it will allow me to drive the wheelchair into the mountains without needing to be concerned for the safety of the driver.
After finding that my home-made radio controls didn’t quite work, I added some capacitors this morning and it’s made a huge difference. Previously, whenever the motors turned, the receiver lost connection to the transmitter and it developed a “mind of its own”. I thought it might have something to do with the motors draining too much power and I was right, the capacitors have fixed the problem, almost. The capacitors I’ve used are just some that I had lying around. One is for a 20v circuit, the other for a 50v circuit, whereas the battery I’m using is only 9v. For the moment, the motors do as they are asked and turn in the right direction, they just don’t have much power. Hopefully when the new capacitors arrive I’ll have a fully working system. Fingers crossed…
I managed to build a radio control transmitter and receiver on Saturday night, attached it to the small prototype and woohoo – one side worked! The next morning I was able to locate the problem, replace one of the integrated circuits and now both sides work, with forwards and reverse… sort of:
The green light on the receiver shows that it has a connection to the transmitter. If the light goes off then it means it has lost its connection. I’m not sure why it’s losing connection at the moment but I would hazard a guess that the motors are drawing too much power and there’s not enough left for the receiver, so it’s thinking caps on and back to the drawing board for this project.