Link maker

the return of the zombie bluefruit ez-link! “Adafruit Industries – Makers, hackers, artists, designers and engineers!

many years ago we developed and sold a pair of products called ez-key ( and ez-link ( product/1588) which implemented Bluetooth Classic HID and SPP respectively. they were popular because we actually did the ‘right’ two – with SPP having control lines for remote programming of boards that would normally use the RTS/DTR/CTS lines for auto reset control.

to do the initial development we had to source CSR chipset BT modules, get them FCC certified, and then develop for them using the very nasty and totally nasty CSR firmware package and IDE. then our module supplier went out of business and everything became extremely tedious to replace and recertify and we ended up breaking the line.

however, maybe we can bring it back from the dead with ESP32 pico modules, small enough to make tiny boards and with classic BT support and no nonsense sdk. best of all, there is a version of the pico that can use external antennas for long range bluetooth!

here is a return to the classic: it is much smaller, but has the same pinout and the same capacities. the LED pair is now a neopixel so we can have more states. the hardware uart on the esp32 is what we use for rx and tx. the pair button uses gpio 0 so we can use that to program the board itself if we want to update the firmware. we attached gpio 15 to ground, which should disable the boot message so it’s a clean uart pipe on SPP. we’ll see if it works!

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