The changes include
- Board length increased by 0.25" to 2" x 3.5"
- Resistor patterns lengthened to allow resistors to lay flat
- Clearance around daughterboard connectors increased
- USB Connector (for power only) changed to a mini-B
- Separate terminal block location for power input
- 3-Pin connectors rotated, with patterns for keyed connector
- Pads added near 3-pin connectors to allow addition of pull-up or pull-down resistors
- S1 and S2 pads allow vertical or right-angle switches
- LED pads allow vertical or right-angle LEDS to be used
- Solder jumper pads re-arranged
- Access to ends of PIC location improved for removing PIC from socket
- Portpin A2 routed to ICSP connector, pin 6.
- Portpin A3 routed to LED4. It had shared B2 with UART connector pin 6.
- Solder jumper added for the UART power connection
I think most of these changes are self-explanatory. Changing the switch and LED patterns allows right-angle parts for accessible controls in an enclosure like I used for the signal Generator. Adding the patterns for pullup/pulldown resistors to the 3-pin connector locations allows for applications like a Dallas OneWire sensor pullup resistor. If a UART-USB adapter is used, the option to disconnect its power connection is handy if power is supplied by another source.
The mini-USB connector is surface mount with through-hole mounting ears. The mounting ears keep it in place and the solder pads are large, so it should not be too difficult to solder. The the exception of this connector and optionally the switches and LEDs, the parts list is the same as for the original board. The daughterboard connector spacing is unchanged.
Any comments are greatly appreciated. I hope others will find this board as useful as I do.