![]() I made this change on my stripboard setup and loaded the code up. We can now assign GPIO4 for the LoRa device SPI SCK and the SD_MMC CLK pin (on GPIO14) is now clear of interference. ![]() GPIO4 on the ESP32CAM is used by the white LED, so to free up this pin for the LoRa device I removed its switching transistor, see picture below. GPIO14 SD-MMC CLKĬould we keep the SD_MMC CLK pin on GPIO14 clear of activity so the SD card behaves more reliably ? You can see from the table above that the clock pin for the SD_MMC is the same as the SPI SCK pin so when the SPI for the LoRa device gets used the SD card may well receive spurious commands that confuse it so perhaps that’s why it locks up after a few cycles. To set the SD_MMC to this 1 bit mode you initialise it with this function The SD_MMC is used in 1 pin mode so that data or commands are clocked via DATA0 only, DATA1,DATA2,DATA3 are not used. When we look at the functions of the pins that the ESP32 uses on the SD_MMC interface to access the SD we see ESP32CAM Pin This is the original circuit I had used for StuartCAM with SX127X It had to be removed or otherwise powered down and put back in to recover.Ĭlearly it would be helpful if the images taken were also saved on the ESP32CAM SD card. So there are going to be conflicts and whilst I initially had it working, with the image transfer, after a few deep sleeps and wake ups the SD card would stop initialising. The ESP32CAM has an SD card but unfortunately it uses the same pins that the SPI interface needs for the LoRa device. ![]()
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