SPI timing problem dissappears when WLAN switched OFF: LOPY & Esp8266
I have this problem for a long time in the ESP8266, so I thought I'll switch to the Lopy to solve it, but the result is identical.
I'm using SPI to send sequentially buffers of 324 bytes to my WS2801 RGB LEDSTRIP to form segmented characters. But about every 5 seconds I think my leds are presenting garbage until the next buffer is send. When I turn the WLAN off, the problem disappears. It is very consistent.
No use of interrupts. And only about 2Mhz because my LEDS can't do much higher. Even lower frequencies giving the same problem.