gmc_logger

gmc_log.php is a PHP-based GMC Geiger Counter logger and viewer. It accepts incoming device readings via HTTP GET, stores them in SQLite, and provides a browser UI with charts and export.

Licensed under AGPL-3.0-only.

Configure GMC Devices

1. Connect your GMC-500+ to WiFi.

2. Navigate to Menu -> Server -> Website.

3. Enter the URL for your server installation.

   Example: Website: 192.168.1.100 URL: gmc_log.php

   (Replace 192.168.1.100 with your actual server IP or domain)

4. Save and exit. The counter should begin sending readings.

What gmc_log.php does

• Logs incoming device data to gmc_logs/gmc_readings.sqlite
• Captures device ID, CPM, ACPM, µSv/h, dose, raw query payload, and client IP
• Shows a web dashboard with a readings table (latest first)
• Displays interactive charts with day/week/month/year tabs
• Supports export to CSV and XLSX

Database details

SQLite DB file:

• gmc_logs/gmc_readings.sqlite

Table created automatically:

• readings(id, timestamp, device_id, cpm, acpm, usv, dose, raw_data, client_ip)

The script auto-creates the DB folder and table if missing.

Logging endpoint behavior

The script treats a request as a log write when any of these query params exists:

• CPM, AID, or GID

Accepted input parameters (case-sensitive):

• Device ID: AID
• CPM: CPM
• ACPM: ACPM
• µSv/h: uSV
• Dose: dose

Defaults when omitted:

• device_id = UNKNOWN
• cpm = 0
• acpm = 0
• usv = 0.0
• dose = 0

On successful insert, response body is:

• OK

Optional device whitelist:

• If whitelist.txt exists in the same folder as gmc_log.php, only listed device IDs are accepted.
• One device ID per line.
• Empty lines are ignored.
• Lines starting with # are treated as comments.
• Device matching is case-insensitive.
• If a device is not in whitelist, the logger returns HTTP 403 with body FORBIDDEN.

Example whitelist.txt:

# Allowed devices
50389795
GMC-ALPHA-01

On unhandled server error:

• HTTP 500
• response body ERROR

Viewer behavior

Opening gmc_log.php without log params shows the dashboard.

Features:

• Last 50 rows shown (MAX_VIEW_ROWS = 50)
• Interactive chart with tabs for Last Day, Last Week, Last Month, Last Year
  • Displays averaged CPM and ACPM over grouped time intervals
• Theme selection via theme (default: dark):
  • light, dark
• Theme preference is saved in localStorage
• Auto-refresh every 60 seconds

The viewer uses gmc_log.css for styling and Chart.js for charts.

Export behavior

Use query parameter:

• export=csv or export=xlsx

Exports include all stored readings (no row limit). Exported columns are: Timestamp, CPM, ACPM, µSv/h, and Dose.

Examples:

• CSV: gmc_log.php?export=csv
• XLSX: gmc_log.php?export=xlsx

Quick usage examples

Sample device log request:

gmc_log.php?AID=50389795&CPM=10&ACPM=7.9&uSV=0.20

Then open:

gmc_log.php

to view data.