CO2 cleanup

Science/src/co2/co2_sensor.cpp

@@ -1,7 +1,5 @@
 #include "co2_sensor.h"
 
-#define CO2_READ_DELAY 500
-
 // The Teensy has two I2C interfaces: Wire and Wire1.
 // This lets us easily switch between them.
 #define WIRE Wire1
@@ -12,31 +10,34 @@ void Co2Sensor::setup() {
   WIRE.begin();
 }
 
-bool Co2Sensor::hasError() {
+int Co2Sensor::checkError() {
   // The exact cases are:
   // - 1: ok
   // - 2: failed
   // - 254: pending
   // - 255: no data
-  // For now we can just check for any error at all.
-  return WIRE.read() != 1;
+  return WIRE.read();
 }
 
 float Co2Sensor::read() {
   // Send the 'r' (read) command to the CO2 sensor.
   WIRE.beginTransmission(address);
   WIRE.write('r');
   WIRE.endTransmission();
-  delay(CO2_READ_DELAY);
 
   // Read the response (a null-terminated string).
   WIRE.requestFrom(address, 20, 1);
-  if (hasError()) return -1;
+  int error = checkError();
+  if (error != 1) {
+    Serial.print("CO2 Error: ");
+    Serial.println(error);
+    return -1;
+  }
   int i = 0;
   char response[20];
   while (WIRE.available()) {
     char character = WIRE.read();
-    response[i] = character;
+    response[i++] = character;
     if (character == 0) break;
   }
 

Science/src/co2/co2_sensor.h

@@ -7,7 +7,7 @@
 class Co2Sensor {
   private:
     int address;
-    bool hasError();
+    int checkError();
 
   public:
     Co2Sensor(int addresss);