After proving that the breadboarded circuit worked as expected, I charged up the Roomba battery and soldered up the Roombaduino circuit.
This time, I was using double-sided perfboard which has its pros and cons ( for me ).
The pros are that the perfboard is better quality than the paper single-sided board and that the pads are less likely to melt and detach when I solder.
The con ( for me ) is that because the pads are double-sided, the solder flows through to the other side. So, if I’m not soldering a component and I want to lay down a power rail, the solder forms in a bump on the other side of where I’m soldering the rail.
I’m sure other people are perfectly happy with it but it doesn’t work for me so I’m going back to single-sided.
I soldered up 3 parts to the circuit.
Firstly, the connection from the Roomba to the circuit through a 5v power regulator. This allows the Nerduino to be powered from the Roomba without needing a separate power input.
Secondly, the 5v to 3.3v power regulator to provide power to the wireless transceiver.
Thirdly, the connection from the Nerduino to the wireless transceiver using the SPI pins.
While the circuit looks compact on the front, I’m still not happy with my wiring ( but I don’t want to take it apart again – maybe in the future ). I need to be more methodical about how I wire stuff to make it more tidy.
What I *am* pleased about is the shield-like design so that the connection to the Nerduino is done through pins and the Roombaduino circuit can stack on top.