From ffa9f3f90a8a9524c320355df04da996c7b9dba7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael=20K=C3=A4ppler?= <michael_kaeppler@web.de>
Date: Sat, 17 Apr 2021 22:46:05 +0200
Subject: [PATCH] co2_sensor: introduce states
* define sensor states
* log every change of state to serial
There is no new functionality added yet.
---
ampel-firmware/co2_sensor.cpp | 40 +++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/ampel-firmware/co2_sensor.cpp b/ampel-firmware/co2_sensor.cpp
index 5dff676..50930c6 100644
--- a/ampel-firmware/co2_sensor.cpp
+++ b/ampel-firmware/co2_sensor.cpp
@@ -25,6 +25,29 @@ namespace sensor {
char timestamp[23];
int16_t stable_measurements = 0;
uint32_t waiting_color = color::blue;
+
+ /**
+ * Define sensor states
+ * INITIAL -> initial state
+ * BOOTUP -> state after initializing the sensor, i.e. after scd.begin()
+ * READY -> sensor does output valid information (> 0 ppm) and no other condition takes place
+ * (NOTE: This state is currently unused)
+ * NEEDSCALIBRATION -> sensor measurements are too low (< 250 ppm)
+ * PREPARECALIBRATION -> forced calibration was initiated, waiting for stable measurements
+ * CALIBRATION -> the sensor does calibrate itself
+ */
+ enum state {INITIAL, BOOTUP, READY, NEEDSCALIBRATION, PREPARECALIBRATION, CALIBRATION};
+ const char *state_names[] = {
+ "INITIAL",
+ "BOOTUP",
+ "READY",
+ "NEEDSCALIBRATION",
+ "PREPARECALIBRATION",
+ "CALIBRATION"
+ };
+ state current_state = INITIAL;
+ void switchState(state);
+
bool should_calibrate = false;
void initialize() {
@@ -49,6 +72,8 @@ namespace sensor {
ESP.restart();
}
+ switchState(BOOTUP);
+
// SCD30 has its own timer.
//NOTE: The timer seems to be inaccurate, though, possibly depending on voltage. Should it be offset?
Serial.println();
@@ -116,9 +141,11 @@ namespace sensor {
Serial.println(F("Waiting until the measurements are stable for at least 2 minutes."));
Serial.println(F("It could take a very long time."));
should_calibrate = true;
+ switchState(PREPARECALIBRATION);
}
void calibrateAndRestart() {
+ switchState(CALIBRATION);
Serial.print(F("Calibrating SCD30 now..."));
scd30.setAltitudeCompensation(config::altitude_above_sea_level);
scd30.setForcedRecalibrationFactor(config::co2_calibration_level);
@@ -137,10 +164,20 @@ namespace sensor {
Serial.println(humidity, 1);
}
+ void switchState(state new_state) {
+ if (new_state == current_state) return;
+ Serial.print(F("Changing sensor state: "));
+ Serial.print(state_names[current_state]);
+ Serial.print(" -> ");
+ Serial.println(state_names[new_state]);
+ current_state = new_state;
+ }
+
void displayCO2OnLedRing() {
if (co2 < 250) {
// Sensor should be calibrated.
led_effects::showWaitingLED(color::magenta);
+ switchState(NEEDSCALIBRATION);
return;
}
/**
@@ -174,8 +211,11 @@ namespace sensor {
//NOTE: Data is available, but it's sometimes erroneous: the sensor outputs zero ppm but non-zero temperature and non-zero humidity.
if (co2 <= 0) {
// No measurement yet. Waiting.
+ switchState(BOOTUP);
led_effects::showWaitingLED(color::blue);
return false;
+ } else if (current_state != PREPARECALIBRATION) {
+ switchState(READY);
}
/**
--
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