Sunday, 1 May 2011

Servo board PCB layout update

Just a quick update on the 20-channel USB servo board with eeprom playback:
this new PCB layout includes the eeprom chip (Atmel's AT45DB041D). Another slight change to the earlier design is that the USB 5v/power supply now goes to the 5V output pin of the regulator rather than the input. This allows the user to connect 4xAA (or 4xAAA) batteries to create a 6V supply or even use a single PP3 (9V) battery to run the device, but safely connect the USB cable at the same time. The original design required the user to disconnect the batteries before connecting the USB cable to download more data to the device. With this new layout, the batteries can safely remain connected and the board still be connected to a PC to download more data.
(a future board with 3.7V rechargeable lipo is in the planning stages but is still some way off!)

Note in this silkscreen and current version of firmware, the servo pin numbering is a little peculiar. This will be addressed in the final version of the firmware!