Signal Timing

2 articles

Tech 19 Sep 2026 7 min read

Raw IR Capture and Replay on ESP32 Depends on Timing, Frame Boundaries, and Carrier Frequency

An infrared receiver does not hand an ESP32 a universal “button code.” At the electrical boundary, it produces a sequence of detected carrier bursts and gaps. A raw capture represents those intervals as alternating mark and space durations, usually in microseconds. A capture such as: uint16_t rawData[] = { 3570, 1620, 554, 342, 498, 1244, 496, 378, // ... }; is therefore a waveform description. Replaying it successfully depends on preserving four things together: the timing sequence, the correct frame boundary, the modulation carrier used for marks, and enough optical output from the IR LED.

ESP32 Infrared

Tech 19 Sep 2026 5 min read

Arduino-IRremote Raw Output: Converting Receive Timings into sendRaw() Data

Arduino-IRremote separates the representation used while receiving an infrared frame from the representation consumed by sendRaw(). The receiver records sampled durations, tracks the gap before the frame separately, and can compensate timing distortion introduced by a demodulating IR receiver. A transmitter, by contrast, expects an array that starts with the first mark and alternates mark and space durations. That boundary matters for AC remotes because their frames can be long and are frequently replayed as RAW data when no protocol-specific encoder is available.

Arduino Infrared