sensor: bme280: Fix bad chip id read after power cycle (f0b5911d) · Commits · Wenxi XU / zephyr

Fix an issue where the BME280 sometimes returns an incorrect chip ID immediately after a power cycle. This causes sensor initialization to fail. According to the datasheet, the sensor requires a 2 ms start-up delay after power is applied. This patch introduces a sleep delay to ensure the required start-up time is respected before reading the chip ID. Signed-off-by:

Filip Stojanovic <filipembedded@gmail.com>

drivers/sensor/bosch/bme280/bme280.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,11 @@ LOG_MODULE_REGISTER(BME280, CONFIG_SENSOR_LOG_LEVEL);
		*/
		#define BME280_MEASUREMENT_TIMEOUT_MS 150

		/* Start-up time - Time to first communication after both Vdd > 1.58V and
		* Vddio > 0.65V
		*/
		#define BME280_START_UP_TIME_MS 2

		/* Equation 9.1, with the fractional parts rounded down */
		#define BME280_EXPECTED_SAMPLE_TIME_MS \
		1 + BME280_TEMP_SAMPLE_TIME + BME280_PRESS_SAMPLE_TIME + BME280_HUMIDITY_SAMPLE_TIME
		@@ -332,6 +337,8 @@ static int bme280_chip_init(const struct device *dev)
		return err;
		}

		k_msleep(BME280_START_UP_TIME_MS);

		err = bme280_reg_read(dev, BME280_REG_ID, &data->chip_id, 1);
		if (err < 0) {
		LOG_DBG("ID read failed: %d", err);

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