diff --git a/README.md b/README.md
index cf8d6693..303f8b50 100644
--- a/README.md
+++ b/README.md
@@ -48,9 +48,9 @@ Works with [ESP32-A1S](https://docs.ai-thinker.com/esp32-a1s) module that includ
 The board showed above has the following IO set
 - amplifier: GPIO21
 - key2: GPIO13, key3: GPIO19, key4: GPIO23, key5: GPIO18, key6: GPIO5 (to be confirmed with dip switches)
-- key1: not sure, something with GPIO36
+- key1: not sure, using GPIO36 in a matrix
 - jack insertion: GPIO39 (inserted low)
-- D4 -> LED: GPIO22 (active low)
+- D4 -> GPIO22 used for green LED (active low)
 - D5 -> GPIO19 as well
 (note that GPIOs need pullups)