Late on Sunday after having a wonderful Father’s day dinner with my Colorado family, I sat down in my shop and decided that I was going to tackle the wiring nightmare. I decided that the best way to manage the tangle of wires was to use an Arduino proto shield.
This is a rather simple circuit board; it ties into the existing headers, gives you solder pads to experiment with, and you can stack another shield on top. I fit this shield between the Arduino Uno and the motor control shield. I had to add some resisters to the board, one 330 ohm to limit the current to the blue LED button, and three 10k pull up resisters for the bumper inputs. One of the things that it important about adding switches to a micro controller is that it only understands 5v and ground. A floating input will cause all kinds of noise and may give false switching.
I normally use 1.25x readers, but for this project I brought out my 2.5x super magnifiers that I bought at Walgreens. In this photo you can see the tangle of wires that need to be routed and landed on the circuit board. You also will notice the Ultrasonic range finder on the front right. Each sensor uses three wires including the switches. The LED button needs four wires. Add in the battery and two motor wires and you can see how keeping the wires in check will be a challenge. I used as much ribbon cable as I could; it looks much neater, and is colour coded to help me remember what goes where. In general I use black as – and red as +. I tried to keep all sensors as yellow or orange. The LEDs I used a colour that matches the colour of light the LED will put out. Keeping to a colour convention really helps.
Next up: mounting the motor control shield and any final touches.