ESP32 SPI master slave communication not working in DMA mode

[headpin]

The ESP32 SPI master & slave sample program given as part of ESP-IDF examples (https://github.com/espressif/esp-idf/tr ... /spi_slave) doesn't work for me.

I flashed the "spi_slave/receiver" on a ESP32 & "spi_slave/sender" firmware on to another ESP32 dev. board. The GPIO pins 12, 13, 14, 15 & 2 are connected from one ESP32 to another (picture attached).

After that when i run the firmware, i see the receiver & sender isn't consistently getting the messages. Intermittently junk characters are outputted. See the screen below. Don't know what is causing this issue. Any help is appreciated.

SPI Sender :-

SPI Sender

Sender.jpg (126.76 KiB) Viewed 2273 times

SPI Receiver :-

SPI Receiver

Receiver.jpg (270.94 KiB) Viewed 2273 times

Wire connection between two ESP32:-

ESP 32 SPI wire connection

ESP32_WireConnection.jpg (65.58 KiB) Viewed 2273 times

[vinu_gss]

which is the devkit ? v1 or v4?