Don't have a clue why modem sleep affects I2S transfer, but here's what helped me troubleshoot the camera driver in the past. Instead of using a real camera as a data source, use signal generator which will produce known pixel data, every time. Then it is much easier to spot what exactly is wrong wi...

Okay, can i finally give the reason why we don't burn the efuse for 1.8V in D2WD. The reason is, if the VDD_SDIO is configured by efuse, it takes some time for the hardware to read efuse values at startup. If the strapping pin configures VDD_SDIO to be 3.3V, then during this time, VDD_SDIO will be 3...

8MHz is used by default as RTC_FAST_CLK.

For example, JTAG, SD HOST, SDIO SLAVE, EMAC can not be remapped to other pins using the GPIO matrix (except for a few signals in SD HOST and EMAC). SPI, I2S and all the low speed peripherals can be remapped. As WiFive said, check the list of GPIO matrix signals.

Here are the few benchmarks we did when writing the SDMMC driver. First are the raw reads and writes — these test the SDMMC peripheral itself by reading/writing certain number of sectors (the number of sectors is given in the "count" column). The tests were run with a no-name SDHC card, which suppor...

temprature_sens_read (sic.) returns ADC counts. To convert these into degrees C you would need to perform some kind of calibration by measuring the temperature with an external tool.

Also s_microseconds rolls over at 32-bit. Can't reproduce this here, can you hint at how you got these results? Attached are graphs of RTC/FRC timers offset w.r.t. the timer on a PC. RTC time was obtained from system_get_rtc_time , FRC time — from get_time_since_boot timelog_rtc_frc.png timelog_frc...

In case you are doing this on the breadboard, re-check your connections. The error being reported is 0x109 or ESP_ERR_INVALID_CRC (see esp_err.h), which usually indicates that there is a signal integrity issue. The driver will use 20MHz clock for most of the cards. If you find that this doesn't work...

Seems like you don't have the partition table uploaded. Have you tried running 'make flash' to upload bootloader, partition table, and the application?

Internal 8 MHz oscillator with calibration Internal RC oscillator with calibration External 32 kHz crystal oscillator for RTC with calibration External 2 MHz to 40 MHz crystal oscillator All of these are indeed supported by the ESP32. Note that while the chip can run from any crystal from 2MHz to 4...