Platformio code

sensor433/src/dht22.cpp

@@ -0,0 +1,149 @@
+/* Fast DHT Lirary
+ *
+ * Copyright (C) 2015 Sergey Denisov.
+ * Written by Sergey Denisov aka LittleBuster (DenisovS21@gmail.com)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version 3
+ * of the Licence, or (at your option) any later version.
+ *
+ * Original library written by Adafruit Industries. MIT license.
+ * 
+ * https://github.com/LittleBuster/avr-dht22
+ */
+
+#include "dht22.h"
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/interrupt.h>
+
+
+#define DHT_COUNT 6
+#define DHT_MAXTIMINGS 85
+
+
+void dht_init(struct dht22 *dht, uint8_t pin)
+{
+    dht->pin = pin;
+    /* Setup the pins! */
+    DDR_DHT &= ~(1 << dht->pin);
+    PORT_DHT |= (1 << dht->pin);
+}
+
+static uint8_t dht_read(struct dht22 *dht)
+{
+    uint8_t tmp;
+    uint8_t sum = 0;
+    uint8_t j = 0, i;
+    uint8_t last_state = 1;
+    uint16_t counter = 0;
+    /*
+     * Pull the pin 1 and wait 250 milliseconds
+     */
+    PORT_DHT |= (1 << dht->pin);
+    _delay_ms(250);
+
+    dht->data[0] = dht->data[1] = dht->data[2] = dht->data[3] = dht->data[4] = 0;
+
+    /* Now pull it low for ~20 milliseconds */
+    DDR_DHT |= (1 << dht->pin);
+    PORT_DHT &= ~(1 << dht->pin);
+    _delay_ms(20);
+    cli();
+    PORT_DHT |= (1 << dht->pin);
+    _delay_us(40);
+    DDR_DHT &= ~(1 << dht->pin);
+
+    /* Read the timings */
+    for (i = 0; i < DHT_MAXTIMINGS; i++) {
+        counter = 0;
+        while (1) {
+            tmp = ((PIN_DHT & (1 << dht->pin)) >> 1);
+            _delay_us(3);
+
+            if (tmp != last_state)
+                break;
+
+            counter++;
+            _delay_us(1);
+
+            if (counter == 255)
+                break;
+        }
+
+        last_state = ((PIN_DHT & (1 << dht->pin)) >> 1);
+
+        if (counter == 255)
+            break;
+
+        /* Ignore first 3 transitions */
+        if ((i >= 4) && (i % 2 == 0)) {
+            /* Shove each bit into the storage bytes */
+            dht->data[j/8] <<= 1;
+            if (counter > DHT_COUNT)
+                dht->data[j/8] |= 1;
+            j++;
+        }
+    }
+
+    sei();
+    sum = dht->data[0] + dht->data[1] + dht->data[2] + dht->data[3];
+
+    if ((j >= 40) && (dht->data[4] == (sum & 0xFF)))
+        return 1;
+    return 0;
+}
+
+uint8_t dht_read_temp(struct dht22 *dht, float *temp)
+{
+    if (dht_read(dht)) {
+        *temp = dht->data[2] & 0x7F;
+        *temp *= 256;
+        *temp += dht->data[3];
+        *temp /= 10;
+
+        if (dht->data[2] & 0x80)
+            *temp *= -1;
+        return 1;
+    }
+    return 0;
+}
+
+uint8_t dht_read_hum(struct dht22 *dht, float *hum)
+{
+    if (dht_read(dht)) {
+        *hum = dht->data[0];
+        *hum *= 256;
+        *hum += dht->data[1];
+        *hum /= 10;
+        if (*hum == 0.0f)
+            return 0;
+        return 1;
+    }
+    return 0;
+}
+
+uint8_t dht_read_data(struct dht22 *dht, float *temp, float *hum)
+{
+    if (dht_read(dht)) {
+        /* Reading temperature */
+        *temp = dht->data[2] & 0x7F;
+        *temp *= 256;
+        *temp += dht->data[3];
+        *temp /= 10;
+
+        if (dht->data[2] & 0x80)
+            *temp *= -1;
+
+        /* Reading humidity */
+        *hum = dht->data[0];
+        *hum *= 256;
+        *hum += dht->data[1];
+        *hum /= 10;
+        if (*hum == 0.0f)
+            return 0;
+        return 1;
+    }
+    return 0;
+}

sensor433/src/dht22.h

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+/* struct dht22 AVR Lirary
+ *
+ * Copyright (C) 2015 Sergey Denisov.
+ * Written by Sergey Denisov aka LittleBuster (DenisovS21@gmail.com)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version 3
+ * of the Licence, or (at your option) any later version.
+ *
+ * Original library written by Adafruit Industries. MIT license.
+ * 
+ * https://github.com/LittleBuster/avr-dht22
+ */
+
+#ifndef __DHT22_H__
+#define __DHT22_H__
+
+#include <stdint.h>
+
+/*
+ * Sensor's port
+ */
+#define DDR_DHT DDRB
+#define PORT_DHT PORTB
+#define PIN_DHT PINB
+
+
+struct dht22 {
+    uint8_t data[6];    /* data from sensor store here */
+    uint8_t pin;        /* DDR & PORT pin */
+};
+
+/**
+ * Init dht sensor
+ * @dht: sensor struct
+ * @pin: PORT & DDR pin
+ */
+void dht_init(struct dht22 *dht, uint8_t pin);
+
+/**
+ * Reading temperature from sensor
+ * @dht: sensor struct
+ * @temp: out temperature pointer
+ *
+ * Returns 1 if succeful reading
+ * Returns 0 if fail reading
+ */
+uint8_t dht_read_temp(struct dht22 *dht, float *temp);
+
+/**
+ * Reading humidity from sensor
+ * @dht: sensor struct
+ * @hum: out humidity pointer
+ *
+ * Returns 1 if succeful reading
+ * Returns 0 if fail reading
+ */
+uint8_t dht_read_hum(struct dht22 *dht, float *hum);
+
+/**
+ * Reading temperature and humidity from sensor
+ * @dht: sensor struct
+ * @temp: out temperature pointer
+ * @hum: out humidity pointer
+ *
+ * Returns 1 if succeful reading
+ * Returns 0 if fail reading
+ *
+ * The fastest function for getting temperature + humidity.
+ */
+uint8_t dht_read_data(struct dht22 *dht, float *temp, float *hum);
+
+
+#endif
+

sensor433/src/main.cpp

@@ -0,0 +1,237 @@
+/*
+   RadioHead attiny85 DHT22 Weather Station
+
+   2021 Stefan Ostermann based on several source from the internetz.
+
+   *NOT working in platformio right now!*
+
+   Sources:
+   https://git.cryhost.de/crycode/attiny85-radiohead-dht22-weather-sensor/-/tree/master
+*/
+
+
+// pin with the LED connected
+#define LED_PIN 4
+
+// blink time for the LED
+#define LED_TIME 200
+
+// pin of the DHT22 sensor
+#define DHT_PIN 1
+
+// the own RadioHead address
+#define RH_OWN_ADDR 0xca // 202
+
+// the server RadioHead address
+#define RH_SERVER_ADDR 0x01
+
+// RadioHead bitrate in bit/s
+#define RH_SPEED 1000
+
+// pins for the radio hardware
+#define RH_RX_PIN 5 // not used, set to a non-existent pin
+#define RH_TX_PIN 3
+#define RH_PTT_PIN 5 // not used, set to a non-existent pin
+
+#include <Arduino.h>
+#include <avr/sleep.h>
+#include <avr/wdt.h>
+#include <util/delay.h>
+
+// for watchdog wakeup
+// https://gist.github.com/dwhacks/8055287
+#ifndef cbi
+#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
+#endif
+#ifndef sbi
+#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
+#endif
+
+
+// DHT22 lib
+// not using the current adafruit dht library, because it's too memory intensive
+#include "dht22.h"
+dht22 dht;
+
+#define RH_BUF_LEN 5
+uint8_t rh_buf[RH_BUF_LEN] = { 0x00, 0x00, 0x00, 0x00, 0x00 };
+
+// reduce the RadioHead max message length to save memory
+#define RH_ASK_MAX_MESSAGE_LEN RH_BUF_LEN
+
+// RadioHead
+#include <RH_ASK.h>
+
+
+// Message Headers:
+#define MSG_START 0x00
+#define MSG_TEMP 0x01
+#define MSG_HUMID 0x02
+#define MSG_BAT 0x03
+#define MSG_ERR 0xee
+
+
+RH_ASK rh_driver(RH_SPEED, RH_RX_PIN, RH_TX_PIN, RH_PTT_PIN);
+
+// watchdog flag
+volatile boolean f_wdt = 1;
+
+// temp / humid toggle
+volatile uint8_t counter = 0;
+
+
+// prototypes:
+void gotoSleep(void);
+
+int getVcc();
+
+void rh_send(uint8_t len);
+
+void setup_watchdog(int ii);
+
+void system_sleep();
+
+void setup() {
+  // setup the LED pin
+  pinMode(LED_PIN, OUTPUT);
+
+  // init the DHT22
+  dht_init(&dht, DHT_PIN);
+
+
+  uint8_t num_blink = 3;
+
+  if (!rh_driver.init()) {
+    num_blink = 5;
+  }
+
+  // blink 3 times
+  for (uint8_t i = 0; i < num_blink; i++) {
+    digitalWrite(LED_PIN, HIGH);
+    _delay_ms(LED_TIME);
+    digitalWrite(LED_PIN, LOW);
+    _delay_ms(LED_TIME);
+  }
+
+  // send start message
+  rh_buf[0] = MSG_START;
+  rh_send(1);
+
+  setup_watchdog(6); // approximately 4 seconds sleep
+
+}
+
+// main loop
+void loop() {
+
+  if (f_wdt) {
+    f_wdt = 0;
+    // turn on the LED
+    digitalWrite(LED_PIN, HIGH);
+
+    // temperature and humidity
+    float t = 0;//float is 32bit = 1byte
+    float h = 0;
+    long battery = 0;
+
+    if (counter % 4 == 0) {
+        rh_buf[0] = MSG_BAT;
+        battery = getVcc();
+        memcpy(&rh_buf[1], &battery, 4);
+        rh_send(RH_BUF_LEN);
+     }else if (dht_read_data(&dht, &t, &h) == 1) {
+      if (counter % 2 == 0) {
+        rh_buf[0] = MSG_TEMP;
+        memcpy(&rh_buf[1], &t, 4);
+      } else if (counter % 2 == 1) {
+        rh_buf[0] = MSG_HUMID;
+        memcpy(&rh_buf[1], &h, 4);
+      }
+      rh_send(RH_BUF_LEN);  
+    } else {
+      // error message
+      rh_buf[0] = MSG_ERR;
+      rh_send(1);
+
+    }
+    counter++;
+
+    // turn off the LED
+    digitalWrite(LED_PIN, LOW);
+    system_sleep();
+    //_delay_ms(1000);
+  }
+
+}
+
+
+// function to send RadioHead messages from the buffer
+void rh_send(uint8_t len) {
+  rh_driver.send((uint8_t *)rh_buf, len);
+  rh_driver.waitPacketSent();
+}
+
+
+
+ISR(WDT_vect)
+{
+  f_wdt = 1; // set global flag
+}
+
+/* set system into the sleep state
+   system wakes up when watchdog is timed out
+*/
+void system_sleep() {
+  //cbi(ADCSRA, ADEN);                   // switch Analog to Digitalconverter OFF
+
+  set_sleep_mode(SLEEP_MODE_PWR_DOWN); // sleep mode is set here
+  sleep_enable();
+
+  sleep_mode();                        // System sleeps here
+
+  sleep_disable();                     // System continues execution here when watchdog timed out
+  //sbi(ADCSRA, ADEN);                   // switch Analog to Digitalconverter ON
+}
+
+/* 0=16ms, 1=32ms,2=64ms,3=128ms,4=250ms,5=500ms
+   6=1 sec,7=2 sec, 8=4 sec, 9= 8sec
+*/
+void setup_watchdog(int ii) {
+
+  byte bb;
+  int ww;
+  if (ii > 9 ) ii = 9;
+  bb = ii & 7;
+  if (ii > 7) bb |= (1 << 5);
+  bb |= (1 << WDCE);
+  ww = bb;
+
+  MCUSR &= ~(1 << WDRF);
+  // start timed sequence
+  WDTCR |= (1 << WDCE) | (1 << WDE);
+  // set new watchdog timeout value
+  WDTCR = bb;
+  WDTCR |= _BV(WDIE);
+}
+
+
+/**
+   From https://github.com/cano64/ArduinoSystemStatus/blob/master/SystemStatus.cpp
+*/
+int getVcc() {
+  //reads internal 1V1 reference against VCC
+  ADMUX = _BV(MUX3) | _BV(MUX2); // For ATtiny85/45
+
+  _delay_ms(5);; // Wait for Vref to settle
+  ADCSRA |= _BV(ADSC); // Convert
+  while (bit_is_set(ADCSRA, ADSC));
+  uint8_t low = ADCL;
+  unsigned int val = (ADCH << 8) | low;
+  //discard previous result
+  ADCSRA |= _BV(ADSC); // Convert
+  while (bit_is_set(ADCSRA, ADSC));
+  low = ADCL;
+  val = (ADCH << 8) | low;
+
+  return (long)val;
+}