ESP32: e-ink + BME680 via SPI not working

[T3N0N]

Hello,

first time using GxEPD2.

i took a look at the example hello world for my 2.9 waveshare v2 display (black & white). Its working.
https://pastebin.com/AvPErxT3
I changed it so i only have .ino file (better for me to use as a beginner)

Its working.

Then I added a BME680 via SPI, used the example code, it works:
https://pastebin.com/B8009AM5

But when I combine the codes the display isn't working anymore:
https://pastebin.com/hYLvg9mD

After troubleshooting, simulating values and disabling lines I figured out the problem is bme.begin():
https://pastebin.com/VPUrj4VC (line 133)

as soon as bme.begin() is called the display is staying white.

Here is a more detailed description of everything:
https://www.reddit.com/r/arduino/comments/1m2f7kw/help_esp32_eink_bme680_via_spi_not_working/

[G6EJD]

Check your use of GPIO pins. Determine which are used for the I2C bus and SPI bus, there will be a conflict.
You can start the I2C bus on different pins (the ones your using) with bme,begin(SCL, SDA);

[G6EJD]

Immediately I note that you're using bme.begin(); which starts the I2C bus which in-turn uses pin-21, so there's your problem, move the CS away from 21 and then you won't get the conflict.

[G6EJD]

Then you need to define the BME spi bus like this:

bme(BME_CS, BME_MOSI, BME_MISO, BME_SCK);

[G6EJD]

Nothing to do with the SPI bus, it's because you're starting the I2C bus with BME.begin which immediately locks pin 21 and stops your SPI bus from working. Study how to use the BME devices on an SPI bus the Adafruit BME library is a good starting point, or just use the I2C bus! No-one uses the SPI bus for the BME devices.

[T3N0N]

@G6EJD thanks for your answers and time.

I changed the BME_CS to 0 and checked with the same code. Same issue.

Then i checked again regarding bme.begin().

As far as i understand.

bme.begin() verifies what is used (I2C or SPI)

depending of what is used:
Adafruit_BME680 bme; // I2C
Adafruit_BME680 bme(BME_CS, MOSI, MISO, SCK); // Software SPI

in my code i already used
Adafruit_BME680 bme(BME_CS, MOSI, MISO, SCK);

I now just used I2C and everything works well. Used 21/22 for SDA/SCL

Will look into SPI another time when I need it again.

Thanks for your support!

Here my current working code:
https://pastebin.com/MVemsM0C

[G6EJD]

Bme680 on the SPI bus will work if you instantiate the SPI bus object correctly. Good to hear you got it working.

GPIO 0 is a strapping pin and for some boards is used for the serial
Port got programming.