From d33bcca5a838ce591c9fa944d8db259d3a8b6b08 Mon Sep 17 00:00:00 2001 From: Richard Hirst Date: Sun, 2 Dec 2012 10:16:09 +0000 Subject: [PATCH] Clarified mapping between servo numbers, GPIO pins and P1 header pins --- ServoBlaster/README.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/ServoBlaster/README.txt b/ServoBlaster/README.txt index 9e6dd66..9726d9d 100644 --- a/ServoBlaster/README.txt +++ b/ServoBlaster/README.txt @@ -83,6 +83,21 @@ directory will also create the necessary files. Further to this, running "make install_autostart" will create those files, plus perform the necessary changes to make servoblaster be automatically loaded at boot. +Note that there are three different ways of referring to a specific servo +control pin: by servo number, by GPIO pin on the processor, or by pin number +on the P1 header on the Pi itself. The following table shows the mapping +between these number schemes: + + Servo GPIO number P1 Pin + 0 4 7 + 1 17 11 + 2 18 12 + 3 21 13 + 4 22 15 + 5 23 16 + 6 24 18 + 7 25 22 + The driver uses DMA channel 0, and PWM channel 1. It makes no attempt to protect against other code using those peripherals. It sets the relevant GPIO pins to be outputs when the driver is loaded, so please ensure that you are not