Earlier this month I took on building, tuning and shipping the last 100 Public Radios we had in stock. In all of the chaos of fulfilling our Kickstarter campaign, I never managed to post a clean video of what the tuning process looks like.
You start by scanning the shipping label. The Raspberry, which is part of our little custom tool, then goes into the database and finds that customer's frequency. Then, you scan the barcode on the radio, and then you drop the radio onto the pogo bed to flash the mcu. The beep you hear at the end of the process is when the Pi acts briefly as an FM transmitter, broadcasting a 1K tone over that particular radio's preset station. That way we know it's been tuned properly, and the speaker is fully functional. Lastly, the Pi updates the database in our google doc. Rinse, wash, repeat.