From 45d7001bb05561d730841d02ffd50b50ed344f58 Mon Sep 17 00:00:00 2001
From: Arthur Roberts <arfa.r@live.com>
Date: Mon, 30 Oct 2023 23:58:44 +0000
Subject: [PATCH] Working! and cleanup collapsed

got better results that passed checksum. NO idea why - I guess just being less
"strict" on what the high / low period was
---
 components/dht22/dht22.c | 67 +++++++++-------------------------------
 1 file changed, 15 insertions(+), 52 deletions(-)

diff --git a/components/dht22/dht22.c b/components/dht22/dht22.c
index 30a25f4..55bec8e 100644
--- a/components/dht22/dht22.c
+++ b/components/dht22/dht22.c
@@ -41,8 +41,10 @@ uint32_t wait_for_signal_to_change_from(int signal_level) {
 
   }
   */
-  while (gpio_get_level(CONFIG_DHT22_DATA_GPIO) == signal_level) {
+  while (gpio_get_level(DATA_GPIO) == signal_level) {
     next_time = esp_timer_get_time();
+    ets_delay_us(2); // just incase of lagging/debouncing/jitter/whatever
+
     if ((next_time - start_time) >= 1000 * 10) {
       return DHT22_TIMEOUT_ERROR;
     }
@@ -56,20 +58,20 @@ uint32_t wait_for_signal_to_change_from(int signal_level) {
 }
 
 dht22_error dht22_read() {
-  uint8_t data[5] = {0, 0, 0, 0, 0};
   uint32_t elapsed_time;
 
+  portDISABLE_INTERRUPTS();
   /*
    * From datasheet:
    *  - Host pulls low "beyond at least 1ms"
    *  - Host pulls up 20us to 40us
    */
-  gpio_set_direction(CONFIG_DHT22_DATA_GPIO, GPIO_MODE_OUTPUT);
+  gpio_set_direction(DATA_GPIO, GPIO_MODE_OUTPUT);
 
-  gpio_set_level(CONFIG_DHT22_DATA_GPIO, 0);
+  gpio_set_level(DATA_GPIO, 0);
   ets_delay_us(5000);
 
-  gpio_set_level(CONFIG_DHT22_DATA_GPIO, 1);
+  gpio_set_level(DATA_GPIO, 1);
   ets_delay_us(25);
 
   /*
@@ -77,10 +79,10 @@ dht22_error dht22_read() {
    *  - DHT pulls low 80us
    *  - DHT pulls high 80us
    */
-  gpio_set_direction(CONFIG_DHT22_DATA_GPIO, GPIO_MODE_INPUT);
+  gpio_set_direction(DATA_GPIO, GPIO_MODE_INPUT);
 
   // Maybe wait here until it goes high?
-  while (gpio_get_level(CONFIG_DHT22_DATA_GPIO) == 1) {
+  while (gpio_get_level(DATA_GPIO) == 1) {
     // wait for a while - should only be 20 uS
   }
 
@@ -101,65 +103,26 @@ dht22_error dht22_read() {
    *     - if 26-28us -> 0 bit
    *     - if 70us -> 1 bit
    */
-  //portENABLE_INTERRUPTS();
-  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--) {
-
+  uint8_t data[5] = {0, 0, 0, 0, 0};
+  for (uint8_t i = 0; i < 40; i++) {
       elapsed_time = wait_for_signal_to_change_from(0);
-      if (elapsed_time == DHT22_TIMEOUT_ERROR) {
+      if (elapsed_time == DHT22_TIMEOUT_ERROR || elapsed_time < 30 || elapsed_time > 70) {
         return DHT22_TIMEOUT_ERROR;
       }
-      if (elapsed_time < 35 || elapsed_time > 65) {
-        return elapsed_time;
-      }
 
       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--;
+      if (elapsed_time > 50) {
+        data[i / 8] |= (1 << (7 - (i % 8)));
       }
   }
   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;