MQ-135 Demo

Source: air_mq135_demo.ino
Prerequisites: MQ-135 analog wiring and calibration assumptions.
Shows: raw ADC/ppm estimate conversion and sensor telemetry transaction flow.

Code


int raw = analogRead(SENSOR_PIN);
float normalized = (float)raw / 4095.0f;
int64_t ppmEstimate = (int64_t)(10.0f + normalized * 990.0f);
 
Instruction ix;
ix.setProgram(programId);
ix.addKey(authorityPub, true, true);
ix.addKey(dataAccountPda, false, true);
ix.writeBytes(RECORD_DATA_DISCRIMINATOR, 8);
ix.writeI64LE((int64_t)raw);
ix.writeI64LE(ppmEstimate);