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Huzzah 8266 breakout i2s data - vs RX issues
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Huzzah 8266 breakout i2s data - vs RX issues

by Jonas_D on Sat Sep 14, 2019 5:30 am

Hi,
I am trying to connect a Adafruit HUZZAH ESP8266 breakout to a Adafruit I2S Stereo Decoder - UDA1334A to be able to play audio. The setup is like this:
ftdi-board <-> Huzzah <-> UDA1334 board. I suspect I am running into an issue with the dual use of the RX pin for UART vs i2s data pin.

SW: it seems i get everything working sw wise.
i2s_begin();
i2s_set_rate(44100);
and later in a loop: i2s_write_lr(sample, sample);

i2s word select and i2s bit clock are verified using oscilloscope and look correct. i2s data does not look correct. I have disconnected the cable from FTDI.

Any ideas what might be the issue would be much appreciated.

Jonas_D
 
Posts: 3
Joined: Sat Sep 14, 2019 5:19 am

Re: Huzzah 8266 breakout i2s data - vs RX issues

by Jonas_D on Sat Sep 14, 2019 9:24 am

Apologize if this should go in another section of the forum - maybe I can get a mod to move it?

Update: I believe the issue I am having is that the level shifter on the breakout board prevents the GPIO-3 being used as an output. Too bad since it is the only way to get i2s data from the 8266 afaik :(

Anyone who know a way to connect an i2s output from a Huzzah 8266 breakout? Or must I find some other piece of hardware?

Jonas_D
 
Posts: 3
Joined: Sat Sep 14, 2019 5:19 am

Re: Huzzah 8266 breakout i2s data - vs RX issues

by Jonas_D on Sat Sep 14, 2019 11:19 am

Finally managed to solve this. There are two things needed:

1) An external 10k pull-down resistor on the RX pin of the Huzzah breakout board. (This will make sure there is an output voltage outside the level shifter. It is just a series diode after all)
2) Disconnecting the FTDI - RX-pin efter programming.

Jonas_D
 
Posts: 3
Joined: Sat Sep 14, 2019 5:19 am

Please be positive and constructive with your questions and comments.