From e751f7b40ce384cadf49c33c23823b9323699edb Mon Sep 17 00:00:00 2001 From: Owen Carter Date: Mon, 6 May 2024 23:38:20 +0200 Subject: [PATCH] Update README.md --- precompiled-trees/README.md | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/precompiled-trees/README.md b/precompiled-trees/README.md index 3b530b5..03edc62 100644 --- a/precompiled-trees/README.md +++ b/precompiled-trees/README.md @@ -1,6 +1,11 @@ # Precompiled device trees: Each folder contains a `.dtb` file, which is the compiled device tree itself, plus a `.dts` with the original source and a `.gpio` file showing the GPIO pin mappings. +The tool/data used to assemble the `.gpio` map files identifies which interface a pin is attached to, but not it's specific function for the interface. +* eg it can say 'pinX and pinY are mapped to a UART', but cannot identify which pin is the TX and which is the RX for it; a limitation of the data, my apologies.. +* You therefore need to reference the D1 pin mapping table to get the exact functions for pins. +* A copy of this table is available here: [reference/d1-pins.pdf](../reference/d1-pins.pdf)). + ## Generic [The generic device tree I will use in my project, suitable for many occasions](./generic) * Has 2x UART (plus the console uart), 2x I2C. 1xSPI