HackerHotel2019Badge/Hardware

Mostly a straight up copy of SHA2017Badge with added IR and I2S Audio.

IR

940nm IR transceiver

Audio

I2S PCM5102A DAC

Errata

Resistor in the way of flashing

We connected our IR receiver to GPIO12 and added a pullup. That caused an issue because by default that pin is a setting for the EEProm voltage selector. During the Hh2019sweatshop we removed the pullups. We hope to set the pullup in software, but are not sure it will work. In the meantime we also found that we could burn a few fuses so that from now on it just works!

./espefuse.py --port /dev/ttyUSB0 --baud 115200 set_flash_voltage 3.3V

We have done this for you already, so only do this if you have similar issues with a different product.

Audiojack reversed

We made another booboo: the audiojack has some reversed pads. (we accidentaly rotated the footprint)

PCM5102	3.5mm Jack
Right	Right
Left	GND
GND	Left

TODO: soldering pictures!

So Left and GND are reversed. This results in a weird sound on headphones. We fixed it partially in software for passive headphones. For active headphones and amplifiers a hardware mod is required, reversing the two pins.