While I still didn't get to get the camera modules to stream any video, I worked a little bit on the servo controller and mechanical parts of the robot.

For one, I discovered why all the frequencies were half what I expected from the code -- I selected the 5V, not 3.3V board in the Arduino IDE, so the code was compiled for the wrong model. Selecting the right board fixes all those issues.

Another thing is the voltage monitor. I added a simple voltage divider on two resistors, and connected it to one of the analog pins on the servo controller. Now I can shut down the servos if the battery voltage reaches a critical level.

I also painted the servo horns at the ends of the legs with some rubber paint, hoping that will let them get a better grip on the floor. Unfortunately, it seems to have very little effect.

Finally, when testing the new servo controller code, I must have shorted one of the cables, and my servo controller released blue smoke. As you all know, those electronic components are actually powered by magical blue smoke inside, and if you release it, they stop working. I'm considering using a 5V one now, because I've run out of 3.3V replacements...

Update: So, after some research, it turns out that the part that got fried is... the on/off switch. Phew. That's literally the cheapest part, so I'm lucky.