force calibration

I can't make `Serial.available()` work, so I just hard-coded the
current CO₂ value

1 files changed, 42 insertions, 1 deletions

diff --git a/main.ino b/main.ino
index bde8892..8597702 100644
--- a/main.ino
+++ b/main.ino
@@ -48,6 +48,9 @@ void showThings(bool all=false) {
   display.updateWindow(0, 0, GxEPD_WIDTH, GxEPD_HEIGHT, false);
 }
 
+unsigned long startTime;
+bool frcDone = false;
+
 void setup() {
 
     Serial.begin(115200);
@@ -95,6 +98,8 @@ void setup() {
         Serial.println(errorMessage);
     }
 
+    startTime = millis();
+
     // this will try to re-init Wire, emit a warning, and carry on
     sensirion_i2c_init();
 
@@ -126,8 +131,44 @@ void loop() {
     char errorMessage[256];
 
     delay(5000);
+    Serial.println(millis());
+
+    if (!frcDone && (millis() - startTime > (3*60 + 30)*1000)) { // 3½ minutes
+      Serial.println("calibration");
+      frcDone=true;
+      display.fillScreen(GxEPD_WHITE);
+      display.setCursor(0,20);
+      display.print("FRC");
+      display.updateWindow(0, 0, GxEPD_WIDTH, GxEPD_HEIGHT, false);
 
+      scd4x.stopPeriodicMeasurement();
+      delay(500);
+
+      uint16_t frcCorrection;
+      error = scd4x.performForcedRecalibration(420,frcCorrection);
+      if (error != 0) {
+        Serial.print("scd4x error ");
+        errorToString(error, errorMessage, 256);
+        Serial.println(errorMessage);
+      }
+      Serial.println(frcCorrection);
+      Serial.println(frcCorrection - 0x8000);
+
+      display.fillScreen(GxEPD_WHITE);
+      display.setCursor(0,20);
+      display.print("FRC ");display.print(frcCorrection);
+      display.updateWindow(0, 0, GxEPD_WIDTH, GxEPD_HEIGHT, false);
+      delay(500);
+      scd4x.startPeriodicMeasurement();
+      delay(2000);
+    }
+    
     error = scd4x.readMeasurement(co2, temperature, humidity);
+    if (error != 0) {
+      Serial.print("scd4x error ");
+      errorToString(error, errorMessage, 256);
+      Serial.println(errorMessage);
+    }
 
     char serial[SPS30_MAX_SERIAL_LEN];
     uint16_t data_ready;
@@ -147,7 +188,7 @@ void loop() {
 
     ret = sps30_read_measurement(&m);
 
-    if (error || ret <0 || co2 ==0) {
+    if (error || ret <0) {
       return;
     }