Otto: Electronics

The first stage of building a dancing, obstacle avoiding robot was to build the body and legs using my 3D printer. The second was to test the electronics before assembly. This would prove to be more eventful than the printing.

I was least sure about all the electronics. They components arrived and… they sure looked okay. I didn’t think the buzzer looked quite right — it looked too big, but I figured that it even if a little lose it should make something approaching a buzzing noise.

The computer itself arrived poorly packaged, with a bunch of the pins bent. I managed to right them without breaking anything.

Arduino Nano, IO Shield, obstacle detection (eyes), motors

And talking of breaking things: I plugged in the Arduino and… nothing. Eventually I realised that I needed to install a Serial-USB device driver. The Otto download came with a CH341 (as it’s creatively called) driver so I installed it, rebooted and… well, when you see text scrolling up the screen when you boot your Mac, either you accidentally jabbed command-V or something bad is happening. In this case, the latter.

Anyway, after a fair degree of panic and dread at the idea of finding and installing another kernel driver from a random website, I found one that seemed to work.

I tried the Arduino before bundling it into the plastic body just to make sure I had the fundamentals down. I plugged in the IO Shield and one of the motors. I press “Upload” in the Arduino app and… seemingly nothing at first. Then blinking. Then the motor started whirring rhythmically.

I picked out a few other example apps and tried those. The best one, at least in the sense that it proved that I was doing the right thing, just blinked one of the boards LEDs. It looked like it worked, so I changed the delay from one to two seconds and saw that that worked too.


Now all the bit are made and shown to be more or less Known Good, it’s time to assemble Otto.