https://sensorrig.com/tags/esp32/Recent content in Esp32 on SensorRig — Real Raspberry Pi Sensor MonitoringHugoen-usTue, 18 Aug 2026 00:00:00 +0000https://sensorrig.com/posts/hc12-packet-loss-retry-protocol/Tue, 18 Aug 2026 00:00:00 +0000https://sensorrig.com/posts/hc12-packet-loss-retry-protocol/The problem The HC-12 module is marketed as a wireless serial link. You wire it to a UART, set the same baud rate on both ends, and bytes flow. That framing works perfectly — until a byte is corrupted or a channel glitch drops a transmission entirely. There is no CRC at the module level, no retry, no acknowledgement, and no way to tell from the receiving UART alone whether the data that arrived is intact.