Tuesday, 3 May 2011

USB servo board eeprom

The little eeprom chips arrived today. I forgot that they were SMT when I designed the USB servo board for PCB manufacture, so the board has an 8-pin DIP socket, and the eeprom chip is SMT. Bugger!

To get around this, I created a simple SMT-to-DIP converter for 8-pin chips:

The SMT chip goes to the left of the 8-pin DIP connectors. I'll put two rows of 4 x 0.1" header pins where the DIP chip would normally go, effectively turning the SMT chip into an 8-pin DIP.

SMT_to_DIP_8PINPrint at 100% no scaling in landscape orientation to create your own press-n-peel transfer to make this SMT-to-DIP converter

If you're making one of these yourself, note that the PCB design has been mirrored (normally we don't bother mirroring designs, as they are reversed on the bottom of any through-hole mounted board anyway). With this design, however, the copper part of the board will be face up, with the SMT chip soldered onto the copper side (rather than the through-hole components being mounted on the top and soldered underneath).
Because of this, the design is mirrored (but when you use press-n-peel/toner transfer to get the image onto the copper board, it'll end up the right way around).

Dont forget to mount the pin headers on the bottom (non-copper) side of the board, with the shorter legs soldered to the top (copper-side) of the board.

The usb servo board was designed to accommodate either a regular 8-pin DIP or our modified SMT-to-DIP board