From e7c8ff0341d1fc3448f27d0de5c2e26681971ef0 Mon Sep 17 00:00:00 2001 From: joan2937 Date: Tue, 2 Jul 2019 21:41:03 +0100 Subject: [PATCH] Update README.md --- README.md | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/README.md b/README.md index e326fca..f7f6ae0 100644 --- a/README.md +++ b/README.md @@ -3,6 +3,12 @@ pigpio is a C library for the Raspberry which allows control of the General Purpose Input Outputs (GPIO). +At the moment pigpio on the Pi4B is experimental. I am not sure if the DMA channels + being used are safe. The Pi4B defaults are primary channel 7, secondary channel 6. + If these channels do not work you will have to experiment. You can set the channels + used by the pigpio daemon by invoking it with the -d and -e options, e.g. + sudo pigpiod -d 5 -e 8 to specify primary 5, secondary 8. + ## Features * Sampling and time-stamping of GPIO 0-31 between 100,000 and 1,000,000 times per second