From 6e3031cdee4b3176a8f7e7cdbf7938d0fc6f3fb4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Xose=20P=C3=A9rez?= Date: Wed, 8 Nov 2017 08:05:10 +0100 Subject: [PATCH] Use own DHT implementation --- code/espurna/dht.ino | 150 +++++++++++++++++++++++++++++++++++++------ code/platformio.ini | 2 - 2 files changed, 129 insertions(+), 23 deletions(-) diff --git a/code/espurna/dht.ino b/code/espurna/dht.ino index 8655b20c..4aaa9325 100644 --- a/code/espurna/dht.ino +++ b/code/espurna/dht.ino @@ -8,20 +8,139 @@ Copyright (C) 2016-2017 by Xose Pérez #if DHT_SUPPORT -#include -#include - -DHT dht(DHT_PIN, DHT_TYPE, DHT_TIMING); - double _dhtTemperature = 0; unsigned int _dhtHumidity = 0; +// ----------------------------------------------------------------------------- +// HAL +// https://github.com/gosouth/DHT22/blob/master/main/DHT22.c +// ----------------------------------------------------------------------------- + +#define DHT_MAX_DATA 5 +#define DHT_MAX_ERRORS 5 +#define DHT_MIN_INTERVAL 2000 +#define DHT_OK 0 +#define DHT_CHECKSUM_ERROR -1 +#define DHT_TIMEOUT_ERROR -2 + +#define DHT11 11 +#define DHT22 22 +#define DHT21 21 +#define AM2301 21 + +unsigned long _getSignalLevel(unsigned char gpio, int usTimeOut, bool state) { + unsigned long uSec = 1; + while (digitalRead(gpio) == state) { + if (++uSec > usTimeOut) return 0; + delayMicroseconds(1); + } + return uSec; +} + +int readDHT(unsigned char gpio, unsigned char type) { + + static unsigned long last_ok = 0; + if (millis() - last_ok < DHT_MIN_INTERVAL) return DHT_OK; + + unsigned long low = 0; + unsigned long high = 0; + + static unsigned char errors = 0; + uint8_t dhtData[DHT_MAX_DATA] = {0}; + uint8_t byteInx = 0; + uint8_t bitInx = 7; + + // Send start signal to DHT sensor + if (++errors > DHT_MAX_ERRORS) { + errors = 0; + digitalWrite(gpio, HIGH); + delay(250); + } + pinMode(gpio, OUTPUT); + digitalWrite(gpio, LOW); + delay(20); + noInterrupts(); + digitalWrite(gpio, HIGH); + delayMicroseconds(40); + pinMode(gpio, INPUT_PULLUP); + delayMicroseconds(10); + + // DHT will keep the line low for 80 us and then high for 80us + low = _getSignalLevel(gpio, 85, LOW); + if (low==0) return DHT_TIMEOUT_ERROR; + high = _getSignalLevel(gpio, 85, HIGH); + if (high==0) return DHT_TIMEOUT_ERROR; + + // No errors, read the 40 data bits + for( int k = 0; k < 40; k++ ) { + + // Starts new data transmission with >50us low signal + low = _getSignalLevel(gpio, 56, LOW); + if (low==0) return DHT_TIMEOUT_ERROR; + + // Check to see if after >70us rx data is a 0 or a 1 + high = _getSignalLevel(gpio, 75, HIGH); + if (high==0) return DHT_TIMEOUT_ERROR; + + // add the current read to the output data + // since all dhtData array where set to 0 at the start, + // only look for "1" (>28us us) + if (high > low) dhtData[byteInx] |= (1 << bitInx); + + // index to next byte + if (bitInx == 0) { + bitInx = 7; + ++byteInx; + } else { + --bitInx; + } + + } + + interrupts(); + + // Verify checksum + if (dhtData[4] != ((dhtData[0] + dhtData[1] + dhtData[2] + dhtData[3]) & 0xFF)) { + return DHT_CHECKSUM_ERROR; + } + + // Get humidity from Data[0] and Data[1] + if (type == DHT11) { + _dhtHumidity = dhtData[0]; + } else { + _dhtHumidity = dhtData[0] * 256 + dhtData[1]; + _dhtHumidity /= 10; + } + + // Get temp from Data[2] and Data[3] + if (type == DHT11) { + _dhtTemperature = dhtData[2]; + } else { + _dhtTemperature = (dhtData[2] & 0x7F) * 256 + dhtData[3]; + _dhtTemperature /= 10; + if (dhtData[2] & 0x80) _dhtTemperature *= -1; + } + + last_ok = millis(); + errors = 0; + return DHT_OK; + +} + +int readDHT() { + return readDHT(DHT_PIN, DHT_TYPE); +} + // ----------------------------------------------------------------------------- // Values // ----------------------------------------------------------------------------- +double getDHTTemperature(bool celsius) { + return celsius ? _dhtTemperature : _dhtTemperature * 1.8 + 32; +} + double getDHTTemperature() { - return _dhtTemperature; + return getDHTTemperature(true); } unsigned int getDHTHumidity() { @@ -30,8 +149,6 @@ unsigned int getDHTHumidity() { void dhtSetup() { - dht.begin(); - #if WEB_SUPPORT apiRegister(DHT_TEMPERATURE_TOPIC, DHT_TEMPERATURE_TOPIC, [](char * buffer, size_t len) { dtostrf(_dhtTemperature, 1-len, 1, buffer); @@ -50,21 +167,12 @@ void dhtLoop() { if ((millis() - last_update > DHT_UPDATE_INTERVAL) || (last_update == 0)) { last_update = millis(); - unsigned char tmpUnits = getSetting("tmpUnits", TMP_UNITS).toInt(); - // Read sensor data - double h = dht.readHumidity(); - double t = dht.readTemperature(tmpUnits == TMP_FAHRENHEIT); - - // Check if readings are valid - if (isnan(h) || isnan(t)) { - - DEBUG_MSG_P(PSTR("[DHT] Error reading sensor\n")); - - } else { + if (readDHT(DHT_PIN, DHT_TYPE) == DHT_OK) { - _dhtTemperature = t; - _dhtHumidity = h; + unsigned char tmpUnits = getSetting("tmpUnits", TMP_UNITS).toInt(); + double t = getDHTTemperature(tmpUnits == TMP_CELSIUS); + unsigned int h = getDHTHumidity(); char temperature[6]; char humidity[6]; diff --git a/code/platformio.ini b/code/platformio.ini index d743f1de..40f68586 100644 --- a/code/platformio.ini +++ b/code/platformio.ini @@ -13,8 +13,6 @@ build_flags_1m = ${common.build_flags} -Wl,-Tesp8266.flash.1m0.ld #https://github.com/me-no-dev/ESPAsyncTCP#9b0cc37 // 2.3.0 compatible #https://github.com/me-no-dev/ESPAsyncTCP#3795e16 // 2.4.0-rc2 compatible lib_deps = - DHT sensor library - Adafruit Unified Sensor https://github.com/xoseperez/Time ArduinoJson https://github.com/me-no-dev/ESPAsyncTCP#9b0cc37