TRMNL EVCC Solar Charging

Monitor your EVCC solar charging setup on TRMNL e-ink displays. See real-time solar production, grid usage, battery state, and EV charging sessions at a glance.

Features

• Solar monitoring -- real-time PV production with power formatting
• Grid tracking -- import/export status with directional indicators
• Battery status -- state of charge and charge/discharge power
• EV charging -- active sessions with power, energy, duration, and solar percentage
• Multi-loadpoint -- support for up to 4 charging points
• Vehicle details -- name, SoC, range, and charge limit
• Charging statistics -- 30-day and lifetime solar share and costs
• Tariff display -- grid price, feed-in rate, and effective home price
• Multiple layouts -- full, half_horizontal, half_vertical, and quadrant templates

Quick Start (TRMNL Cloud)

1. Install the Plugin

1. Go to your TRMNL Dashboard
2. Navigate to Plugin Directory
3. Search for "EVCC Solar Charging"
4. Click Add to My Plugins
5. Copy the Webhook URL from the plugin settings

2. Set Up the Collector

# Create a directory for the collector
mkdir trmnl-evcc && cd trmnl-evcc

# Download the required files
curl -O https://raw.githubusercontent.com/ingm4r/trmnl-plugin-evcc/main/collector/docker-compose.yml
curl -O https://raw.githubusercontent.com/ingm4r/trmnl-plugin-evcc/main/collector/config.example.yaml

# Create your config from the example
cp config.example.yaml config.yaml

3. Configure

Edit config.yaml with your EVCC details:

interval: 300
timezone: Europe/Berlin

evcc_url: http://evcc:7070

webhook: https://usetrmnl.com/api/custom_plugins/your-webhook-id

max_loadpoints: 2
power_unit: auto

4. Start the Collector

docker compose up -d

The collector will now send data to your TRMNL device every 5 minutes.

Quick Start (Self-Hosted Terminus)

If you run a self-hosted Terminus instance, the collector can serve data via HTTP instead of pushing to webhooks.

A ready-to-use Terminus template is included at src/terminus/full.liquid. See the Terminus Setup Guide for full instructions.

Configuration Reference

Config File Settings

Setting	Description	Default
interval	Collection interval in seconds (0 = run once)	300
timezone	Timezone for display (e.g., Europe/Berlin)	UTC
evcc_url	EVCC instance URL	Required
webhook	TRMNL webhook URL	Optional
max_loadpoints	Maximum loadpoints to include (1-4)	4
power_unit	Power display: auto, W, or kW	auto
serve.enabled	Enable HTTP server for Terminus	false
serve.port	HTTP server port	8080
serve.host	HTTP server bind address	0.0.0.0

Environment Variables

For running without a config file (single instance mode):

Variable	Description	Required
EVCC_URL	EVCC instance URL	Yes
WEBHOOK_URL	TRMNL webhook URL	No
INTERVAL	Collection interval in seconds	No (default: 0)
TZ	Timezone for display	No (default: UTC)
MAX_LOADPOINTS	Maximum loadpoints to include	No (default: 4)
POWER_UNIT	Power display unit	No (default: auto)
SERVE_PORT	Enable HTTP serve mode on this port	No

Plugin Display Settings

Configure these in your TRMNL plugin settings:

Setting	Description	Options	Default
Show Energy Overview	Display solar, grid, and home power	Yes/No	Yes
Show Battery	Display battery status	Yes/No	Yes
Show Loadpoints	Display charging loadpoint cards	Yes/No	Yes
Max Loadpoints	Maximum loadpoints shown	1-4	2
Show Vehicle Details	Display vehicle name, SoC, range	Yes/No	Yes
Show Statistics	Display 30-day charging stats	Yes/No	No
Show Tariff	Display energy price info	Yes/No	No
Power Unit	How to display power values	Auto/W/kW	Auto

Docker Compose Examples

With Config File (Recommended)

services:
  trmnl-evcc-collector:
    image: ghcr.io/ingm4r/trmnl-evcc-collector:latest
    container_name: trmnl-evcc-collector
    restart: unless-stopped
    volumes:
      - ./config.yaml:/app/config.yaml:ro
    environment:
      - TZ=Europe/Berlin

With Environment Variables

services:
  trmnl-evcc-collector:
    image: ghcr.io/ingm4r/trmnl-evcc-collector:latest
    container_name: trmnl-evcc-collector
    restart: unless-stopped
    environment:
      - EVCC_URL=http://evcc:7070
      - WEBHOOK_URL=https://usetrmnl.com/api/custom_plugins/xxx
      - INTERVAL=300
      - TZ=Europe/Berlin
      - MAX_LOADPOINTS=2

Docker Run (Single Instance)

docker run -d \
  --name trmnl-evcc-collector \
  --restart unless-stopped \
  -e EVCC_URL=http://evcc:7070 \
  -e WEBHOOK_URL=https://usetrmnl.com/api/custom_plugins/xxx \
  -e INTERVAL=300 \
  -e TZ=Europe/Berlin \
  ghcr.io/ingm4r/trmnl-evcc-collector:latest

Template Sizes

The plugin includes templates for all TRMNL screen configurations:

Template	Resolution	Description
full	800x480	Energy overview + battery + loadpoints
half_horizontal	800x240	Compact energy bar + active loadpoint
half_vertical	400x480	Energy overview + single loadpoint
quadrant	400x240	Minimal energy stats
terminus/full	800x480	Terminus/BYOS adapted full layout

EVCC Requirements

• EVCC v0.207+ recommended (for full /api/state response)
• The collector reads from EVCC's REST API (/api/state)
• No API key or authentication required (EVCC exposes its API without auth)
• Ensure the EVCC instance is reachable from the collector container

Troubleshooting

View Collector Logs

docker compose logs -f

Common Issues

"Cannot connect to EVCC..."

• Verify your EVCC URL is accessible from the Docker container
• If using localhost, try using your machine's IP address or host.docker.internal

Times are wrong

• Set the correct timezone in your config.yaml (e.g., Europe/Berlin, America/New_York)

Loadpoints not showing

• Check max_loadpoints is set high enough in both collector config and plugin settings
• Verify EVCC has loadpoints configured

Development

Local Development with Docker

cd collector
cp config.example.yaml config.yaml
# Edit config.yaml with your settings
docker compose -f docker-compose.dev.yml up --build

Running Directly with Python

cd collector
pip install -r requirements.txt
python evcc_collector.py --config config.yaml

Template Development

Use the trmnlp CLI to preview templates:

trmnlp serve
# Open http://localhost:4567 to see the rendered template

Test data files are available in the examples/ directory.

Resources

• TRMNL -- E-ink smart display
• EVCC -- Solar charging controller
• EVCC API Documentation
• Terminus (BYOS) -- Self-hosted TRMNL

License

MIT License -- see LICENSE for details.