Friday, December 23, 2016

Gherkin Assembly

Gherkin assembly notes

Test fitting all the parts together before soldering anything. You may need to trim/grind some parts to make them fit.

Board assembled with diodes and optional resistors.
Choose appropriate value resistors for the LEDs you are using.
100Kohm and 100ohm resistors for MOSFET.
Diodes are polarized, align the black stripe with the stripe on the board.

Bottom of board with SOIC-8 MOSFET and socket.
This socket was a 28 pin socket I trimmed down to 24 pins. Also the cross supports were cut off since the plastic PCB pins from the switch would press against them.

Here's a nice video on soldering SOIC parts: https://www.youtube.com/watch?v=fq8A95AQFYU
There is a dot instead of a line on the Gherkin PCB.

This is a low profile socket. You can see the pins of the switch will touch the Pro Micro. They will need to be trimmed after soldering.

Full height socket. There is enough clearance to not need to trim the pins. There is also enough height for Holtite sockets. You may need to take a Dremel grinder bit to make some grooves in the socket so the Holtites don't touch the inner wall of the socket.

Pro Micro with diode leads soldered on to make it socketable

You can see what it looks like when soldering the diodes pins in this post. http://www.40percent.club/p/socketing-pro-micro.html

Pro Micro installed. Don't install upside down, it will short out.

The unused pins from the Pro Micro are broken out to the pins below. You may want to attach some wires or a small switch to GND and RESET ( pins 8 and 9 ) to make it easier to get into the bootloader.