First of all I really really like the Stamp C3(U), I find the plastic cover totally great. But what frustrates me (maybe I'm doing something wrong) is that SPI is not usable.
The reason is that for classic full-duplex SPI on a ESP32C3 you need SPI2 (Fast SPI) which leads to the following:
- MOSI = FSPID = GPIO7 --> nicely on the PIN header
- MISO = FSPIQ = GPIO2 --> the status LED on Stamp C3(U), not on the header
- CLK = FSPICLK = GPIO6 --> nicely on the PIN header
- CS = FSPICS0~5 = GPIO10 for CS0 --> nicely on the PIN header and in general chip select is a bit easier
I really don't get why GPIO2 was used for the status LED, from what I get there's nothing special about it. So I think / strongly believe / am convinced that SPI peripherals just don't work on the stamp...