RayPowerMeter
A next-generation 4-channel RF power and SWR measurement system designed for accuracy, speed, and seamless station integration. RayPowerMeter pairs with RayCoupler sensors and a companion Qt desktop app for powerful visualization and control.
Overview
RayPowerMeter is an advanced, multi-channel RF measurement and monitoring instrument designed for modern amateur radio stations, test benches, and high-power amplifier setups. Built around the ESP32-S3 DevKitC-1 microcontroller, it provides four channels of true forward/reflected power measurement using external RayCoupler sensors (1–4 units).
Unlike typical single-channel meters or low-resolution MCU-based sensors, RayPowerMeter uses dedicated 16-bit ADS1115 A/D converters to achieve exceptional precision, stability, and repeatability—even at low drive levels where meter resolution normally collapses.
With both USB/Serial and Wi-Fi connectivity, plus a fully featured cross-platform desktop application (Qt), RayPowerMeter delivers real-time multi-channel monitoring, peak capture, SWR protection logic, high-speed graphing, and logging capabilities. The system is designed to scale to multiple RayPowerMeter units on the same network, ideal for stations with several amplifiers and antenna systems.
Key Features
4 Independent RF Channels
- Simultaneous monitoring of up to four RF paths.
- Forward, reflected, SWR, and PEP per channel.
- Ideal for amp input/output, multiple antennas, or stacked systems.
High Accuracy Measurements
- Dedicated ADS1115 16-bit ADCs for precision readings.
- Significantly better linearity and resolution than on-chip 12-bit MCU ADCs.
- Stable readings at low drive levels and across wide dynamic range.
Multi-Point Calibration
- Enter multiple calibration points to correct detector curvature and compression.
- Separate profiles per channel and per power range.
- Restores linearity for accurate low-, mid-, and high-power readings.
High-Speed Sampling & PEP
- Fast sampling engine suitable for SSB, CW, AM, and digital modes.
- Sample-and-hold logic for accurate peak envelope power (PEP).
- Short voice bursts are captured cleanly without under-reporting.
Real-Time Graphing & Dashboards
- Qt desktop app with multi-channel dashboard.
- Power vs time, SWR “pie” indicators, gain graphs, and histograms.
- Per-channel panels plus combined station view.
SWR Protection Logic
- User-selectable SWR trip thresholds per channel.
- Fail-safe latching with manual reset from the app or GPIO.
- Can key external cutoff relays or amplifier inhibit lines.
Logic I/O & Aux Inputs
- Four logic outputs, four logic inputs for amp, tuner, or antenna control.
- Aux analog inputs (0–20 V) for supply rails, bias, or temperature sensors.
- Designed to integrate with high-power amplifier protection schemes.
Desktop Host Application
- Native Qt app for Windows, macOS, and Linux (including Raspberry Pi).
- Auto-range or manual power ranges, SWR visual tools, and channel linking.
- Optional audio announcements and alarms for critical thresholds.
Connectivity & Logging
- USB/Serial for direct connection to the host PC.
- Wi-Fi for remote monitoring and networked stations.
- 1-second resolution data logging with timestamps for all channels.
Scales with Your Station
- Supports multiple RayPowerMeter units on the same LAN.
- Assign each unit to specific amps, antennas, or operating positions.
- Contest and multi-op stations can monitor many RF paths from one host app.
RayCoupler Integration
RayPowerMeter is designed from the start to integrate with the RayCoupler product line. Each coupler provides a stable, wide-band forward and reflected RF sample, giving the meter clean inputs for high-accuracy calculations.
Up to four RayCoupler units can be connected at once, enabling:
- Input and output monitoring of an HF amplifier chain.
- Multiple antenna feeds or switching systems.
- Drive vs output gain measurements for linearity testing.
- Real-time comparison of different antenna paths or bands.
Technology & Design
Core Platform
- MCU: ESP32-S3 DevKitC-1 with USB-OTG and Wi-Fi.
- ADC: ADS1115 16-bit converters for precision measurement.
- Time-coherent sampling across all channels.
- Firmware tuned for RF measurement, peak logic, and SWR protection.
Qt Host Application
- Custom RF-oriented widgets and charts.
- Configurable layouts for amp bench, station view, or lab mode.
- Profiles for different couplers, bands, and power classes.
- Planned integration hooks for future RF StateSide products.
Use Cases
- HF linear amplifier monitoring and protection.
- Multi-antenna station and SO2R systems.
- SSB drive optimization using gain graphs and peak tracking.
- Antenna tuning with live SWR visualization.
- Bench testing couplers, filters, amps, and RF modules.
- Remote/Internet-controlled stations via Wi-Fi.
- Large contest or multi-op stations using multiple RayPowerMeter nodes for full-path visibility.
- Long-term power and duty-cycle logging for development or contest stations.
Availability
RayPowerMeter is currently in active development as part of the RF StateSide ecosystem. Hardware prototypes, firmware modules, and the companion Qt application will be documented as they mature. Watch this page and the RF StateSide GitHub organization for build notes, schematics, and early beta software releases.
Gallery
Future space for PCB renders, enclosure photos, and screenshots of the RayPowerMeter desktop app.
Interested in RayPowerMeter?
If you're developing or operating a high-performance HF station and want multi-channel power, SWR, and gain visibility tied directly into your amplifiers and RF chain, RayPowerMeter is being designed for you. Reach out if you'd like to follow development or participate in early testing.