ESP32-C6 and CC1101-based sub-GHz gateway supports Honeywell Ramses II protocol

Developed by Elecram in the Netherlands, the ESP32-C6 and CC1101 transceivers-based Sub-GHz gateway is designed to bridge Zigbee/WiFi networks with HVAC systems that support the Honeywell Ramses II sub-GHz protocol. This means you can now control those with platforms like Home Assistant or your smartphone.

Elecram also provides a pre-designed 3D-printable enclosure for easy integration. The housing supports both M2.5 and M3 mounting options, which makes it suitable for home automation, DIY prototyping, and integrating sub-GHz devices with modern networks.

ESP32-C6 and CC1101 sub-GHz gateway specifications:

• Wireless Modules
  • Espressif Systems ESP32-C6-MINI-1-N4
    • SoC – Espressif Systems ESP32-C6
      • CPU
        • Single-core 32-bit RISC-V clocked up to 160 MHz
        • Low-power RISC-V core @ up to 20 MHz
      • Memory/Storage – 320KB ROM, 512KB SRAM
      • Wireless – 2.4 GHz WiFi 6, Bluetooth 5.0, and 802.15.4 radio (for Thread/Zigbee)
    • Storage – 4MB flash
    • Antenna – PCB antenna
  • TI CC1101 transceiver module
    • Operates in the 855–925 MHz range
    • Optimized packet handling and interrupt timing for stability
    • Enhanced FIFO/timeout recovery to prevent hangs
• USB – 1x USB Type-C port for power and programming
• Misc
  • Reset and User button
  • User LED
• Power – 5V via USB-C port
• Dimensions
  • PCB – 60 x 30 mm
  • Enclosure – 63.5 x 33.5 x 12.65 mm

In terms of software, this gateway runs open-source firmware based on a fork version of the RAMSES ESP project, adapted for a single-core ESP32-C6 with PlatformIO support. It integrates with ESPHome and can be easily connected to Home Assistant for automation. The firmware improvements include non-blocking MQTT publishing, timezone and SNTP fixes, and more robust CC1101 handling. Source code, design files, and setup guides are available on GitHub. The files for the board’s 3D printer enclosures can be downloaded on Thingiverse.

Previously, we have seen the CC1101 used in different types of hacking tools like the Mayhem v2 Flipper Zero expansion, the Interrupt hacking tool, and on the ESP32-based DisruptorX V2 tool. But this project uses this module for smart home integration and HVAC control.

The ESP32 and CC1101-powered sub-GHz gateway can be purchased for $35 on Tindie.

Debashis Das

Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication

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