From bb274d367a990c97284f392a68f44ac7e6266445 Mon Sep 17 00:00:00 2001
From: mj <mj370@protonmail.com>
Date: Thu, 18 Nov 2021 19:56:23 +0100
Subject: [PATCH] Linear change of LED color according to CO2 level

---
 fw/Core/Src/main.c | 45 ++++++++++++++++++++++++++++++++++-----------
 1 file changed, 34 insertions(+), 11 deletions(-)

diff --git a/fw/Core/Src/main.c b/fw/Core/Src/main.c
index 29c72cd..f82857a 100644
--- a/fw/Core/Src/main.c
+++ b/fw/Core/Src/main.c
@@ -124,6 +124,7 @@ static void MX_TIM2_Init(void);
 static void MX_TIM22_Init(void);
 /* USER CODE BEGIN PFP */
 void USART2_TX_Buffer(uint8_t* buffer_tx, uint16_t buffer_tx_len);
+void CO2_to_color(uint16_t co2, uint16_t co2_limit_yellow, uint16_t co2_limit_red);
 /* USER CODE END PFP */
 
 /* Private user code ---------------------------------------------------------*/
@@ -306,7 +307,6 @@ int main(void)
 
 		  new_baud = LL_USART_GetBaudRate(USART2, SYSTICK_FREQ_HZ, LL_USART_OVERSAMPLING_16);
 	  }
-
 	  /* It is time for measurement */
 	  if (tim21_elapsed_period == 1)
 	  {
@@ -339,20 +339,25 @@ int main(void)
 		  tim21_elapsed_period = 0;
 	  }
 	  /* TEST END */
-	  if (sensor_config.led_on) {
+	  if (sensor_config.led_on == 1) {
 		  if (co2_valid == 1) {
-			  if (CO2 <= sensor_config.led_co2_alert_limit1) {
-				  /* CO2 is OK -> GREEN */
-				  rgbled_set_color(RGBLED_GREEN);
+			  if (sensor_config.led_smooth == 0) {
+				  if (CO2 <= sensor_config.led_co2_alert_limit1) {
+					  /* CO2 is OK -> GREEN */
+					  rgbled_set_color(RGBLED_GREEN);
 
-			  } else if ((sensor_config.led_co2_alert_limit1 < CO2) && (CO2 <= sensor_config.led_co2_alert_limit2)) {
-				  /* CO2 is NOT OK -> YELLOW */
-				  rgbled_set_color(RGBLED_YELLOW);
+				  } else if ((sensor_config.led_co2_alert_limit1 < CO2) && (CO2 <= sensor_config.led_co2_alert_limit2)) {
+					  /* CO2 is NOT OK -> YELLOW */
+					  rgbled_set_color(RGBLED_YELLOW);
 
 
-			  } else if (sensor_config.led_co2_alert_limit2 < CO2) {
-				  /* CO2 is CRITICAL -> RED */
-				  rgbled_set_color(RGBLED_RED);
+				  } else if (sensor_config.led_co2_alert_limit2 < CO2) {
+					  /* CO2 is CRITICAL -> RED */
+					  rgbled_set_color(RGBLED_RED);
+				  }
+			  } else {
+				  /* */
+				  CO2_to_color(CO2, sensor_config.led_co2_alert_limit1, sensor_config.led_co2_alert_limit2);
 			  }
 		  } else {
 			  /* CO2 invalid */
@@ -892,6 +897,24 @@ int8_t modbus_transmit_function(uint8_t *buffer, uint16_t data_len)
 	USART2_TX_Buffer(buffer, data_len);
 	return MODBUS_OK;
 }
+
+void CO2_to_color(uint16_t co2, uint16_t co2_limit_yellow, uint16_t co2_limit_red)
+{
+	const uint16_t co2_limit_green = 400; /* fresh air, lowest possible value */
+
+	uint32_t co2_full_span;
+	uint32_t intensity;
+
+	if (co2 < co2_limit_green) {
+		rgbled_set_color(RGBLED_GREEN);
+	} else if (co2 > co2_limit_red) {
+		rgbled_set_color(RGBLED_RED);
+	} else {
+		co2_full_span = co2_limit_red - co2_limit_green;
+		intensity = (co2 - co2_limit_green) * 255 / co2_full_span;
+		rgbled_set_color(intensity, 255 - intensity, 0);
+	}
+}
 /* USER CODE END 4 */
 
 /**