Test and Troubleshoot

Step 9: Test and Troubleshoot

As I mentioned, testing is important after every step and sub-step.

Bits of trouble encountered:

We blew a couple Max chips in the process by connecting a 9V battery to the voltage regulator, so we downsized to using 2 AA batteries, which work much better.
After soldering the LED board, the whole circuit stopped working altogether. After ascertaining that the Arduino still worked (blink that pin 13 LED to test), we checked all the connections from the Max chip to the power supply (pins 4, 9, 18, and 19). This got the circuit on again, though it wasn't working correctly.
To get the circuit working correctly, we labeled each LED with the Max pin number to which it is connected. (You'll see an example of this in the third picture below.) We took notes on which lights weren't working right, and which pins were the issue. We had a lot of issues with pin 17, for two reasons: it has a lot of incoming connections, and it's right next to pin 18, which has a lot of connected resistors.
As we pointed out, it is very crowded from pin 14 to pin 23 on the Max chip, and you will likely have trouble with lights connected to these pins. We had to cheat a little and use tape and hot glue to separate the connections between pins.