Can't scale up BlinkM network.

Hi Rob,
The startup light script that comes default on BlinkMs will cause each BlinkM to draw 60mA as it goes full white. This means 35 BlinkMs at once would draw 35*60mA = 2100mA, which is greater than your power supply. This is likely your problem.

You can program each BlinkM's startup behavior with the "Set Startup Parameters" ('B') command. An example command byte string to not play a script on a startup is "{'B', 0,0,0,10,0}". The first zero is the most important one: it controls whether or not a script is played. The '10' in there sets the default fade speed for any subsequence fade commands. The datasheet contains more details.

If you've set the startup mode to not play a script and it's still not working, how long and what type is the cabling you're using? I2C networking wasn't meant to go beyond a single PCB and we're all just lucky it works at a few meters. If you have strange or really long cabling, you might run into issues. For cabling, I've had success with standard ribbon cable and IDC connectors as described in my BlinkM Cylon post. Your pullup resistors should be no smaller than 4.7k. If you make them too large, the I2C devices can't pull the lines down.

You are working on one of the largest BlinkM networks I know of (I've only built ones up to 24 BlinkMs). Let us know how things work out!