This week we received a batch of PCBs and amongst them was the latest revision of our USB TFT breakoutboard. This board is the first board that features a new ICSP footprint, which occupies less space on the PCB and should improve testing and programming times at Seeed.
The footprint consist of a key hole and 5 small pads. Each pad carries an ICSP signal (/MCLR, V+, GND, PGC and PGD). One of those pads has a small hole, which helps to align the probe better. The spacing between the pads is the bare minimum required so the pogopins wouldn’t touch.
The design is based on little pogopins we found on our geek tour in Shenzhen, China. Due to the lack of a datasheet, we measured the pogopins precisely and made our own.
We were eager to while away the winter doldrums by hacking on this board, but after soldering it we realized there’s no adapter for the new programming header yet. We needed a way to program it quickly.
We hacked this programming adapter together with a couple of pogopins. Here’s the final result alongside the regular .1″ programing header we normally use. The first person that guesses the datasheet on which this photo was taken will receive a free PCB of the USB TFT breakout!
To make the adapter:
- First we used nail polish to make the outside of each pin less conductive
- Next we carefully aligned the pins on a piece of tape and glued them together with hot-glue
- Hot-glue is fantastic stuff, but it cooled too quickly and everything got misaligned No worries, we just reworked it into submission with our trusty hotair station.
Not the most repeatable process, but a PCB and laser cut acrylic programming probe is on the way. We expect it will be much more elegant.
After the glue set we tried out the new programmer. Amazingly it worked right away the first time and without any hassle!