arthurr/esp-air-monitor
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Looked into another DHT22 library for inspiration

Browse Source 
Still not working and I really can't tell why
This commit is contained in:
Arthur Roberts
2023-10-30 23:37:36 +00:00
parent 69a7732017
commit 822b73597e
1 changed files with 36 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
components/dht22/dht22.c
View File

@@ -56,7 +56,7 @@ uint32_t wait_for_signal_to_change_from(int signal_level) {
}
dht22_error dht22_read() {
uint8_t data[5] = {0};
uint8_t data[5] = {0, 0, 0, 0, 0};
uint32_t elapsed_time;
/*
@@ -102,8 +102,12 @@ dht22_error dht22_read() {
* - if 70us -> 1 bit
*/
//portENABLE_INTERRUPTS();
for (int byte_i = 0; byte_i <= 4; byte_i++) {
for (int bit_i = 7; bit_i >= 0; bit_i--) {
uint8_t byte_i = 0;
uint8_t bit_i = 7;
for (int i = 0; i < 40; i++) {
//for (int byte_i = 0; byte_i <= 4; byte_i++) {
// for (int bit_i = 7; bit_i >= 0; bit_i--) {
elapsed_time = wait_for_signal_to_change_from(0);
if (elapsed_time == DHT22_TIMEOUT_ERROR) {
@@ -116,18 +120,46 @@ dht22_error dht22_read() {
elapsed_time = wait_for_signal_to_change_from(1);
if (elapsed_time < 60 || elapsed_time > 80) {
data[byte_i] |= (1 << bit_i);
// TODO: check why this doesn't work
//data[i / 8] |= (1 << (7 - (i % 8));
}
//ESP_LOGE(TAG, "bit: %i, byte: %i, elapsed_time: %lu", bit_i, byte_i, elapsed_time);
//}
///*
if (bit_i == 0) {
bit_i = 7;
byte_i++;
} else {
bit_i--;
}
}
portENABLE_INTERRUPTS();
ESP_LOGE(TAG, "data[0-4]: %x %x %x %x %x", data[0], data[1], data[2], data[3], data[4]);
// 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];
float relative_humidity = data[0];
relative_humidity *= 0x100;
relative_humidity += data[1];
relative_humidity /= 10;
float temp = data[2] & 0x7f;
temp *= 0x100;
temp += data[3];
temp /= 10;
if (data[2] & 0x80) {
temp *= -1;
}
ESP_LOGE(TAG, "rh: %f, temp: %f", relative_humidity, temp);
if (data[2] & 0x80) {
_dht22_temperature = -1 * _dht22_temperature;
}
ESP_LOGE(TAG, "rh: %i, temp: %i", _dht22_relative_humidity / 10, _dht22_temperature / 10);
uint8_t checksum_val = (data[0] + data[1] + data[2] + data[3]) & 0xff;
if (checksum_val != data[4]) {
_dht22_relative_humidity = UINT16_MAX;