From ab3c84e2599fb8fc70c9bca4f4d2a897fd8af0e5 Mon Sep 17 00:00:00 2001
From: andreask <andreask>
Date: Sat, 9 May 2020 20:23:58 +0200
Subject: [PATCH] brightness measurement via LED

---
 Firmware/src/main.cpp    | 54 +++++++++++++++++++++++++++++++++++++---
 Firmware/src/secconfig.h | 22 +++++++++++++---
 2 files changed, 69 insertions(+), 7 deletions(-)

diff --git a/Firmware/src/main.cpp b/Firmware/src/main.cpp
index 4cd090d..9e0a51a 100644
--- a/Firmware/src/main.cpp
+++ b/Firmware/src/main.cpp
@@ -55,12 +55,12 @@
 #endif
 
 // Create Sensor Class
-#ifdef HAS_BME280
+#if defined HAS_BME280 || defined HAS_BME280_BRIGHTNESS
   #include <BME280.h>
   BME280 sensor;
 #endif
 
-#ifdef HAS_SHT21
+#if defined HAS_SHT21 || defined HAS_SHT21_BRIGHTNESS
   #include <SHT21.h>
   SHT21 sensor;
 #endif
@@ -80,6 +80,33 @@ void blink(uint8_t num) {
 }
 #endif
 
+
+#if defined HAS_SHT21_BRIGHTNESS || defined HAS_BME280_BRIGHTNESS
+
+int16_t brightness()
+{
+  unsigned int counter;
+  // LED Anode auf OUTPUT/LOW
+  pinMode(LED_A, OUTPUT);
+  digitalWrite(LED_A, LOW);
+
+  // LED Kathode auf OUTPUT/HIGH
+  pinMode(LED_K, OUTPUT);
+  digitalWrite(LED_K, HIGH);
+  delayMicroseconds(4);
+
+  // Kathode wieder auf INPUT
+  pinMode(LED_K,INPUT);
+  digitalWrite(LED_K, LOW);
+  // In einer Schleife zählen, bis Kathode auf LOW geht
+  for ( counter = 0; counter < 65000; counter++) {
+    if (digitalRead(LED_K)==0) break;
+     delayMicroseconds(5);
+  }
+  return counter;
+}
+#endif
+
 // Setup Wakeup Interrupt Timer
 void init_wdt()
 {
@@ -213,6 +240,13 @@ void loop()
       int32_t temperature;
       int32_t humidity;
     } __attribute__ ((packed)) data;
+  #elif defined HAS_SHT21_BRIGHTNESS
+    struct lora_data {
+      uint8_t bat;
+      int32_t temperature;
+      int32_t humidity;
+      int16_t brightness;
+    } __attribute__ ((packed)) data;
   #elif defined HAS_BME280
     struct lora_data {
       uint8_t bat;
@@ -220,18 +254,30 @@ void loop()
       int32_t humidity;
       int32_t pressure;
     } __attribute__ ((packed)) data;
+  #elif  defined HAS_BME280_BRIGHTNESS
+    struct lora_data {
+      uint8_t bat;
+      int32_t temperature;
+      int32_t humidity;
+      int32_t pressure;
+      int16_t brightness;
+    } __attribute__ ((packed)) data;
   #endif
 
   // Get Sensor Data
-  #ifdef HAS_BME280
+  #if defined HAS_BME280 || defined HAS_BME280_BRIGHTNESS
     sensor.getData(&data.temperature, &data.pressure, &data.humidity);
   #endif
 
-  #ifdef HAS_SHT21
+  #if defined HAS_SHT21 || defined HAS_SHT21_BRIGHTNESS
     data.temperature = (int32_t)(sensor.getTemperature()*100);
     data.humidity    = (int32_t)(sensor.getHumidity()*100);
   #endif
   
+  #if defined HAS_SHT21_BRIGHTNESS || defined HAS_BME280_BRIGHTNESS
+    data.brightness = (int16_t)(brightness());
+  #endif
+
   // Add Battery Voltage, 20mv steps, encoded into 1 Byte
   uint32_t batv = readVcc();
   data.bat = (uint8_t)(batv/20);
diff --git a/Firmware/src/secconfig.h b/Firmware/src/secconfig.h
index 7cd8dde..06c1bcd 100644
--- a/Firmware/src/secconfig.h
+++ b/Firmware/src/secconfig.h
@@ -9,10 +9,17 @@
      #define HAS_NO_SENSOR - No Sensor, just send Battery Voltage (Beacon Mode)
      #define HAS_SHT21  - Sensirion SHT21 Temperature + Humidity Sensor
      #define HAS_BME280 - Bosch BME280 Temperature + Humidity + Pressure Sensor
-   
+     #define HAS_SHT21_BRIGHTNESS  - SHT21 + Brightness via LED
+     #define HAS_BME280_BRIGHTNESS - BME280 + Brightness via LED
+
    * LED Support
      #define LED_PIN PIN_A7 - LED is connected to ATTiny84 Pin A7 on TinyTX SMD / TinyLora
-     
+
+   * Brightness Measurement
+     LED connected between 2 pins, switched in reverse direction for brightness measurement
+     #define LED_K PIN_A7 - LED Cathode
+     #define LED_A PIN_B2 - LED Anode
+
    * Time between Measurements
      #define SLEEP_TIME 528 - Time in Seconds between Measurements. Try it out to get a good Approximation
      Examples from my Tests::
@@ -42,4 +49,13 @@
   #define RFM69_GATEWAY     1 // NodeID of the Receiver, 1-255
   #define RFM69_TXPOWER    31 // Transmitting Power 0-31, see datasheet for details
   #define RFM69_ENCKEY    "0123456789ABCDEF" // AES encryption key, exactly 16 characters, if set messages will be encrypted using AES 128bit
-*/
\ No newline at end of file
+*/
+
+/*
+// LoRa RFM95 + BME280 + Brightness Measurement
+  #define RF_LORA
+  #define HAS_BME280_BRIGHTNESS
+  #define LED_K PIN_A7
+  #define LED_A PIN_B2
+  #define SLEEP_TIME 544 // ca
+  */