Client for the Duplo Train Pusher

ESPHome client for controlling a Lego Duplo train.

Two variants are available:

Variant	Config file	MCU	Communication	Backend required
HTTP (original)	train-pusher-client.yaml	ESP8266 (D1 Mini)	HTTP REST API	Yes (train-pusher)
BLE (direct)	train-pusher-ble.yaml	ESP32 (D1 Mini 32)	Bluetooth LE	No

Table of Contents

• Project configuration
• Firmware upload
• BLE variant
• Hardware
  • Button to pin mappings

Project configuration

Activate Python virtualenv and install required packages. Check ESPHome docs for Python requirements:

python3 -m pip install virtualenv
python3 -m virtualenv venv
source venv/bin/activate
pip install -r requirements.txt

To deactivate Python virtualenv run deactivate

NOTE: Python virtualenv MUST be activated with source venv/bin/activate each time before using esphome

Firmware upload

NOTE: First time upload should be performed via cable, all subsequent uploads could be performed Over-The-Air (OTA upload)

To build and upload firmware activate Python virtualenv and install packages from the requirements.txt as described in the Project configuration section above and then run ESPHome:

esphome run train-pusher-client.yaml

In order to check device logs run:

esphome logs train-pusher-client.yaml

More details on ESPHome usage could be found via esphome -h command and on the official website

BLE variant

The BLE variant (train-pusher-ble.yaml) uses an ESP32 to communicate directly with the train via Bluetooth Low Energy, eliminating the need for the Node.js backend.

Requirements

• D1 Mini 32 (ESP32) -- the ESP8266 does not support BLE
• Same TLC5947 LED driver and button hardware as the HTTP variant

Discovering the train's BLE MAC address

Turn on the train and scan for BLE devices using one of these methods:

1. nRF Connect mobile app (iOS/Android) -- look for a device named LPF2 Smart Hub
2. ESP32 BLE scan -- flash the config with a placeholder MAC, check the ESPHome logs for discovered devices

GPIO pin differences from ESP8266

Button	ESP8266 (D1 Mini)	ESP32 (D1 Mini 32)	Reason
Stop	GPIO 0	GPIO 25	GPIO 0 is a strapping pin on ESP32
Brake	GPIO 2	GPIO 26	GPIO 2 drives onboard LED on ESP32

All other pins (4, 5, 12, 13, 14, 15, 16) remain the same.

Configuration

Set the train's BLE MAC address in train-pusher-ble.yaml substitutions:

substitutions:
  train_mac_address: "AA:BB:CC:DD:EE:FF"

Build and flash

source venv/bin/activate
esphome run train-pusher-ble.yaml

Hardware

Button to pin mappings

Button	TLC5947 pin	D1mini pin
Green Backward	22	5
Green Forward	23	12
White	19	4
Yellow	14	5
Blue	17	2
Red	20	0