From 3a397cfb4b99dd9f109e039fe27b1993c5d27f5e Mon Sep 17 00:00:00 2001
From: Roman Priesol <roman@priesol.net>
Date: Wed, 30 Sep 2026 21:17:20 +0200
Subject: [PATCH] ANT+ via ESPHome: mcu-nrf-ant (RadiANT) sends heart rate to
 mcu-nrf-dk over packet_transport

Replaces the E73 running the archived nrf-ant-bridge firmware and drops
mcu-ant-host, which read that bridge's line protocol.
---
 mcu-ant-host.yaml    | 34 ----------------------------------
 mcu-nrf-ant.yaml     | 43 +++++++++++++++++++++++++++++++++++++++++++
 mcu-nrf-dk.yaml      | 23 ++++++++++++++---------
 secrets.yaml.default |  3 +++
 4 files changed, 60 insertions(+), 43 deletions(-)
 delete mode 100644 mcu-ant-host.yaml
 create mode 100644 mcu-nrf-ant.yaml

diff --git a/mcu-ant-host.yaml b/mcu-ant-host.yaml
deleted file mode 100644
index 3799743..0000000
--- a/mcu-ant-host.yaml
+++ /dev/null
@@ -1,34 +0,0 @@
-# Hardware: Linux host (ESPHome host platform)
-# Pinout:
-#   /dev/ttyACM3  nRF52840 DK running ant_bridge (J-Link VCOM, usb-SEGGER_J-Link_000683492497)
-substitutions:
-  device: ant-host
-  name: ANT+ Host
-  comment: ANT+ heart rate monitor via nRF52840 DK bridge
-
-esphome:
-  name: mcu-${device}
-  friendly_name: ${name}
-  comment: ${comment}
-
-host:
-
-packages:
-  api: !include common/api.yaml
-  logger: !include common/logger.yaml
-
-external_components:
-  - source: github://randybb/esphome-components
-    components: [ant_plus]
-
-uart:
-  # the host uart only takes /dev/<name>, not /dev/serial/by-id/...
-  port: /dev/ttyACM3
-  baud_rate: 115200
-
-ant_plus:
-  device_number: 655730
-  heart_rate:
-    name: Heart Rate
-    filters:
-      - throttle: 1s
diff --git a/mcu-nrf-ant.yaml b/mcu-nrf-ant.yaml
new file mode 100644
index 0000000..2a22d11
--- /dev/null
+++ b/mcu-nrf-ant.yaml
@@ -0,0 +1,43 @@
+---
+# Hardware: Nordic nRF52840 DK
+# Pinout:
+#   P0.06   UART0 TX                   -> logger (J-Link VCOM)
+#   P1.01   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
+esphome:
+  name: mcu-nrf-ant
+  friendly_name: nRF ANT+
+
+# needs the esphomeplatformzephyr fork (esphome-zephyr); RadiANT needs NCS
+zephyr:
+  variant: NRF52
+  board: nrf52840dk/nrf52840
+  framework:
+    type: ncs
+
+logger:
+  hardware_uart: UART0
+
+external_components:
+  - source: github://randybb/esphome-components
+    components: [ant_plus]
+
+ant_plus:
+  network_key: !secret ant_plus_network_key
+  device_number: 655730
+  heart_rate:
+    id: heart_rate
+    name: Heart Rate
+
+uart:
+  id: link
+  port: UART1
+  tx_pin: P1.01
+  baud_rate: 115200
+
+packet_transport:
+  - platform: uart
+    uart_id: link
+    update_interval: 1s
+    sensors:
+      - heart_rate
diff --git a/mcu-nrf-dk.yaml b/mcu-nrf-dk.yaml
index 97e4a2b..13558dc 100644
--- a/mcu-nrf-dk.yaml
+++ b/mcu-nrf-dk.yaml
@@ -9,7 +9,7 @@
 #   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                   <- Ebyte E73-TBM-01 (E73-2G4M04S1B, nRF52832) ant_bridge TX (P0.24)
+#   P1.01   UART1 RX                   <- mcu-nrf-ant UART1 TX (P1.01), packet_transport; plus GND
 esphome:
   name: mcu-nrf-dk
   friendly_name: nRF DK
@@ -34,20 +34,25 @@ api:
   encryption:
     key: !secret api_key
 
-external_components:
-  - source: github://randybb/esphome-components
-    components: [ant_plus]
-
-# ANT+ from the E73 test board running ant_bridge (the ANT stack doesn't work on NCS 3.4)
+# ANT+ values from mcu-nrf-ant (second nRF52840 DK) over UART
 uart:
+  id: ant_link
   port: UART1
   rx_pin: P1.01
   baud_rate: 115200
 
-ant_plus:
-  device_number: 655730
-  heart_rate:
+packet_transport:
+  - platform: uart
+    uart_id: ant_link
+    providers:
+      - name: mcu-nrf-ant
+
+sensor:
+  - platform: packet_transport
+    provider: mcu-nrf-ant
+    remote_id: heart_rate
     name: Heart Rate
+    internal: false
     filters:
       - throttle: 1s
 
diff --git a/secrets.yaml.default b/secrets.yaml.default
index 14a8e6b..55e65e3 100644
--- a/secrets.yaml.default
+++ b/secrets.yaml.default
@@ -32,3 +32,6 @@ ble_beacon_toyota_yaris_honda_minor: 61958
 
 # Thread active dataset (hex TLV) from Home Assistant
 thread_tlv: "0E080000000000010000"
+
+# ANT+ network key (8 bytes hex), from thisisant.com
+ant_plus_network_key: "0000000000000000"