CPM Exporter is a Python script that reads Counts Per Minute (CPM) data from a Geiger counter device and exposes it as a Prometheus metric. This tool is useful for monitoring radiation levels and integrating the data with Prometheus-based monitoring systems.

In this case, this script is used with the following device: GQ GME-300E Plus

• Reads CPM data from a Geiger counter device via serial communication
• Exposes CPM data as a Prometheus metric
• Configurable sleep interval between data retrievals
• Logging for easy troubleshooting

• Python 3.x
• pyserial
• prometheus_client

1. Clone this repository or download the cpm_metrics.py script.
2. Install the required Python packages:

pip install pyserial prometheus_client

Run the script with:

python cpm_metrics.py [sleep_interval]

• sleep_interval (optional): Time in seconds between data retrievals. Defaults to 60 seconds if not specified.

The script uses the following constants, which can be modified in the code if needed:

• SERIAL_PORT: The serial port for the Geiger counter device (default: '/dev/cpm')
• SERIAL_BAUDRATE: The baud rate for serial communication (default: 57600)
• SERIAL_TIMEOUT: Timeout for serial operations in seconds (default: 3)
• DEFAULT_SLEEP_INTERVAL: Default sleep interval between data retrievals in seconds (default: 60)

The script starts a Prometheus HTTP server on port 8000. The CPM data is exposed as a Gauge metric named geiger_cpm with the description "Counts per minute from Geiger counter".

To scrape this metric with Prometheus, add the following job to your Prometheus configuration:

scrape_configs:
  - job_name: 'cpm_exporter'
    static_configs:
      - targets: ['localhost:8000']

The script logs information, warnings, and errors to the console. The log format includes timestamps and log levels for easy debugging.

The script includes error handling for various scenarios, including:

• Invalid sleep interval input
• Failure to start the Prometheus server
• Serial communication errors
• Unexpected errors during execution

In case of critical errors, the script will log the error and exit with a non-zero status code.

This project is licensed under the GNU General Public License v3.0. See the LICENSE file for details.