From 2e8b67807284af58c3c078e04496e20fa17cd48a Mon Sep 17 00:00:00 2001
From: Roman Priesol <roman@priesol.net>
Date: Wed, 30 Sep 2026 23:15:10 +0200
Subject: [PATCH] nrf-ant, nrf-dk: two-way UART on the DK default pins, wires
 crossed

Both boards use UART1 RX P1.01 / TX P1.02 so Home Assistant data can reach
the ANT+ node's transmitters; on the default pins the ANT+ node no longer
needs the RX pin workaround.
---
 mcu-nrf-ant.yaml | 11 +++++------
 mcu-nrf-dk.yaml  |  5 ++++-
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/mcu-nrf-ant.yaml b/mcu-nrf-ant.yaml
index 304c09b..81a62de 100644
--- a/mcu-nrf-ant.yaml
+++ b/mcu-nrf-ant.yaml
@@ -4,8 +4,8 @@
 #   P0.06   UART0 TX                   -> logger (J-Link VCOM)
 #   P0.13   LED 1 (active low)         -> ANT+ Connected (a configured device is received)
 #   P0.14   LED 2 (active low)         -> ANT+ Unknown Device (an unconfigured one is in range)
-#   P1.01   UART1 TX                   -> mcu-nrf-dk UART1 RX (P1.01), packet_transport; plus GND
-#   P1.02   UART1 RX                   (unused)
+#   P1.01   UART1 RX                   <- mcu-nrf-dk UART1 TX (P1.02), packet_transport
+#   P1.02   UART1 TX                   -> mcu-nrf-dk UART1 RX (P1.01), packet_transport; plus GND
 # Radio: ANT+ receiver (RadiANT), no network of its own; values go to mcu-nrf-dk
 # ANT+ devices:
 #   655730   Garmin HRM-Pro          heart rate
@@ -147,10 +147,9 @@ ant_plus:
 uart:
   id: link
   port: UART1
-  tx_pin: P1.01
-  # unused, but must be set: the fork otherwise keeps the board's default RX, which on
-  # the DK is P1.01 too, and the UART hears its own transmissions
-  rx_pin: P1.02
+  # the DK's default UART1 pins, same on both boards, wires crossed
+  tx_pin: P1.02
+  rx_pin: P1.01
   baud_rate: 115200
 
 packet_transport:
diff --git a/mcu-nrf-dk.yaml b/mcu-nrf-dk.yaml
index 653ef79..31640e7 100644
--- a/mcu-nrf-dk.yaml
+++ b/mcu-nrf-dk.yaml
@@ -9,7 +9,8 @@
 #   P0.16   LED 4 (active low)         -> LED 4 (light binary)
 #   P0.24   Button 3 (active low)      -> Button 3 (binary_sensor gpio)
 #   P0.25   Button 4 (active low)      -> Button 4 (binary_sensor gpio)
-#   P1.01   UART1 RX                   <- mcu-nrf-ant UART1 TX (P1.01), packet_transport; plus GND
+#   P1.01   UART1 RX                   <- mcu-nrf-ant UART1 TX (P1.02), packet_transport; plus GND
+#   P1.02   UART1 TX                   -> mcu-nrf-ant UART1 RX (P1.01), packet_transport
 # ANT+ values (Garmin HRM-Pro, Concept2 PM5, Garmin Tempe, Garmin Varia RTL515) come from mcu-nrf-ant
 esphome:
   name: mcu-nrf-dk
@@ -41,7 +42,9 @@ api:
 uart:
   id: ant_link
   port: UART1
+  # the DK's default UART1 pins, same on both boards, wires crossed
   rx_pin: P1.01
+  tx_pin: P1.02
   baud_rate: 115200
 
 packet_transport: