After much iteration on the firmware for the keyboard, I decided on finally assembling the device, in spite of not being completely finished. It will continue to be a work-in-progress, but I need to move on to other projects for now. Once I finish some other projects, I’ll come back to this one.
Parts for the Job
![ABS plastic cover](http://142.93.194.197/wp-content/uploads/2017/02/WP_20170113_16_09_19_Pro-1-300x169.jpg)
Thankfully, I already had all the parts I needed by this point: hardware odds and ends, a AA battery holder with a switch, glue of various sorts, and a 3D printed ABS plastic cover (courtesy of my father, who is really into 3D printing now). We designed the cover with a slot for the TFT headers, as well as for the mounting holes. Additionally, the cover needed a small indentation for the SD card holder which protruded from the bottom of the TFT’s board.
Assembling the Main Electronics
![Assembling PCB and TFT, from the bottom](http://142.93.194.197/wp-content/uploads/2017/02/WP_20170113_16_12_43_Pro-1-300x169.jpg)
I designed the revision “B” keyboard toy boards with mounting holes to match the TFT board’s mounting holes; and instead of the complicated wire harness, I opted to put a female header on my board to exactly match the header on the TFT. The boards could then sandwich the cover through the header slot, and I could secure them with machine screws, nuts and nylon washers. I went with nylon washers for the bottom to ensure that the hardware wouldn’t come into contact with and pads on the PCB and cause shorts.
Glue!
![Assembled device, from the front](http://142.93.194.197/wp-content/uploads/2017/02/WP_20170113_16_12_37_Pro-1-300x169.jpg)
Before gluing and assembling the case and cover, I drilled another small hole in the keyboard cover, since I would need to wire the battery holder to my PCB, now effectively inside the case. After plugging the keyboard and battery holder wire harnesses into my main PCB, I superglued the ABS cover onto the hole in the keyboard cover. Once that was semi-secure, I superglued the battery holder onto the back of the cover. I needed to carefully choose the position and orientation so that both the switch and battery were still accessible.
The Finished Product
![Fully assembled keyboard toy](http://142.93.194.197/wp-content/uploads/2017/02/WP_20170113_18_03_55_Pro-1-300x169.jpg)
The only thing left now was to add batteries and test. It was a success! It also seems to hold together fairly well. We’ll see how long it holds up now that the kids are playing with it.