I'm yet to figure it out. Would have been better if people at bosch could provide us with some more details on this.
I sent a email to the Bosch Customer support and their response was the following (Quoting from the email below):
Thank you very much for your inquiry and your interest in our products.
We have deployed an online community to support developers and customers:
The Bosch Sensortec Community includes a MEMS Sensors Forums, a comprehensive Knowledge Base and a Frequently Asked Questions section. Therefore, we kindly ask you to visit the community and post your question in the MEMS Sensors Forum where our experts will answer your question.
The 8x BME688 are connected via SPI. The chips selects of each are connected to an I2C GPIO expander. So in order to communicate, before and after the SPI transaction, the appropriate chip select has to be set low/high. We are currently in the process of refining the code to be extendable to the wider audience. In the meantime, please find information to get started.
- TI TCA6408 I2C-GPIO expander or I2C address 20h.
- NXP PCF8523 RTC with backup coin-cell on I2C address 68h.
- SD card connected via SPI using a chip select connected to the ESP32's pin 33.
- 2 buttons connected to pin 14 and 32 of the ESP32 with active low. (requires and pull-up from the ESP32.
Thanks for the details. Using this, I'll be able to successfully communicate with the BME688 sensors from any microcontroller.
Glad to hear that you guys are working on more generic/open firmware for the bme board.
Is the source code for the esp32-huzzah board available yet? Like I could only find the bin file.
I am too currently trying to communicate with the BME688 development board w/o using the Bosch AI software. Would you be interested in exchanging some experience on the way? Write me here (you find my email in the link): http://tinymailto.com/nkdnnlr