Microcontroller revision history
Revision 0 Original
Revision 1 4/4/05
Note: this revision makes only one change that affects the operation of the Rev 0 board. It revises Encoder 1 wiring to work properly. Encoder 1 is not currently used on the Rev 0 board because of the problem. Instructions will be provided to make this correction on the Rev 0 board.
Revised layout for pullup resistors on MOT0, MOT1 & MOT2 to accommodate 1/4 watt resistors.
Moved the "PROG/RUN" silkscreen legend to copper top layer so that it can be seen (without silkscreen) and reversed it to "RUN/PROG" to indicate switch positions properly.
Added provisions for a two pin header terminal in parallel with the RUN/PROG switch so that an external switch can be attached. (leaving board switch in open position).
Moved power LED ground trace farther away from board mounting hole.
Corrected wiring on board for the battery monitor circuit.
Added I2C pull-up resistor mounting pads.
Added ground to pin T2 of accelerometer mounting for PicoTilt board for period setting resistor.
Moved Encoder 1 A input from pp3 (H1-18) to IRQ (H1-46) note: using PP inputs for two encoders had caused some errors reading both encoders simultaneously. Having each on a separate interrupt should work. Recommend using ENC 0 & 2 for the two differential drive motors since they operate the same and ENC1 for another function since it works a bit differently (captures on trailing edge rather than leading edge).
Added two holes for optional hold down plate on USB chip.
Revision 2 1/3/06
Added 2 grounds to 10 pin accelerometer layout. implements mod 001 to earlier boards.
Added better jumper pads for RC motor drive selection. implements mod 002 to earlier boards.
Revision 3 1/12/07
Added a 7 pin header to allow installation of an alternative rate gyro module
replaced hardwire jumpers to select power voltage on RC ports with IDC pins and jumpers.
Added silkscreen identifiers for each output port.
Went to lead free PCB.