Files
esp-air-monitor/components/dht22/dht22.c
Arthur Roberts 5efca6b3c0 Figured out how to turn on PSRAM
Now it looks like you can just allocate from a regular "malloc"
Code ran successfully (afaict) when writing to 7MB - didn't seem
to when doing 8MB. Not 100% sure why, but I don't think it'll
matter tbh
2023-10-24 22:07:59 +01:00

44 lines
1.2 KiB
C

#include "dht22.h"
#include "sdkconfig.h"
#include "esp_log.h"
#define DATA_GPIO CONFIG_DHT22_DATA_GPIO
#if DATA_GPIO == -1
#error "Please define your DHT22 GPIO Data Pin"
#endif /* CONFIG_DHT22_DATA_GPIO == -1 */
static const char* TAG = "DHT22";
deci_percent _dht22_relative_humidity = UINT16_MAX;
deci_degrees_c _dht22_temperature = INT16_MIN;
dht22_error dht22_read() {
uint8_t data[5] = {0};
// TODO: Actually figure out how to read the data from the chip.
// TODO test that data[x] << 8 will be promoted to 16bits otherwise I'm shifting them to just zeros
_dht22_relative_humidity = data[0] << 8 | data[1];
_dht22_temperature = (data[2] & 0x7f) << 8 | data[3];
if (data[2] & 0x80) {
_dht22_temperature = -1 * _dht22_temperature;
}
uint8_t checksum_val = (data[0] + data[1] + data[2] + data[3]) & 0xff;
if (checksum_val != data[4]) {
_dht22_relative_humidity = UINT16_MAX;
_dht22_temperature = INT16_MIN;
ESP_LOGE(TAG, "Error in final checksum check");
return DHT22_CHECKSUM_ERROR;
}
return DHT22_OK;
}
deci_percent dht22_relative_humidity() {
return _dht22_relative_humidity;
}
deci_degrees_c dht22_temperature() {
return _dht22_temperature;
}