diff --git a/LORA-IRR.md b/LORA-IRR.md
index c49153b..cbeb421 100644
--- a/LORA-IRR.md
+++ b/LORA-IRR.md
@@ -126,6 +126,8 @@ Pins
 
 The [pinout guide for the Node151](https://resource.heltec.cn/download/LoRa_Node_151/LoRa_Node_151_Pinout_Diagram.pdf).
 
+The pins PA13(SWDIO)/14(SWCLK) are used for programming.
+
 The default pins PB5-7,9 are used as active low controls for the relays.
 They are mapped to channels 0 through 3 respectively.  The LED on PB8
 is mapped to channel 4.  This is useful for testing if a command works