The MPU9250 is quite old, I am surprised you are using it for a new project. The problem with it is, the MPL software is on your host processor, which means any missing gyro data can mess the whole algo. Also, it is VERY sensitive to mag calibration, if it is not calibrated correctly, your reading ...

Today you can take a Bosch BMX160 or Invensense icm-20948 (or similar chips) that do all the fusion and filtering and queue onto a hardware fifo inside the chip, and fires a GPIO when the fifo hits a percent mark. Here you can not miss any data. If you are collecting each raw sample manually, this ...

Well, why don't you write to Cadence and Xtensa team to reveal full esp32/lx6 documents for technical reference and assembly manuals. You can try RMT of ESP as it behaves similar to SPI and has full-duplex behavior. Like I said we have to wait for Cadence people to give us full docs and relevant as...

Ad. FreeRTOS: I don't have hardware by myself now so I cannot give some real data to show if it's too heavy or not. I don't want to blame you for using FreeRTOS generally - I ment this thread to be about state of ESP32 hardware, docs and IDF. I did not want it to be about quadcopters. I knew that I ...

FreeRTOS is not heavy at all. To say "It would make better sense to write low level drivers without FreeRTOS " is really not true. FreeRTOS, makes running many threads at one very simple. You can even set a section of code as CRITICAL if you need to something timing intensive so there are no task s...

Making quadcopters is just my hobby. I think that ESP32 fills a huge gap on market - it is powerful and there are ready to use modules (DevKitC V4). I also love the fact that it uses Xtensa architecture. But it hurts to see how many features / configuration of SPI hardware have been planned and are ...

(Mod note: Changed the title of this topic; it was 'ESP32 not ready for production') Hello guys, I've been working with ESP32 for about one year. I have built quadcopter firmware based on ESP-IDF but soon understood that it will be impossible to make it fully working. Whole IDF is written inefficien...

In general: The Xtensa docs on the core we use are pretty good. The problem with it is that, as far as I know, we have them because we signed an NDA with Cadence, making it hard to just spread them around. We know this is an issue, and we're working on getting the info out one way or another. Do yo...

See https://esp32.com/viewtopic.php?t=293. There are newer versions of Xtensa ISA manual but we will not probably ever see them.

Also hold signal does not seem to work (bits usr_hold_pol, usr_dout_hold, usr_din_hold, usr_dummy_hold, usr_addr_hold, usr_cmd_hold and usr_prep_hold in USER register). So WP and HOLD signals does not seem to have any function in classic SPI - it should be mentioned in docs. Both signals are only us...