First steps towards history plotting

include/GxEPD2_display_selection_new_style.h

@@ -42,8 +42,8 @@
 //#define GxEPD2_DRIVER_CLASS GxEPD2_260_M01 // GDEW026M01  152x296, UC8151 (IL0373)
 //#define GxEPD2_DRIVER_CLASS GxEPD2_270     // GDEW027W3   176x264, EK79652 (IL91874)
 //#define GxEPD2_DRIVER_CLASS GxEPD2_371     // GDEW0371W7  240x416, UC8171 (IL0324)
-#define GxEPD2_DRIVER_CLASS GxEPD2_420     // GDEW042T2   400x300, UC8176 (IL0398)
+//#define GxEPD2_DRIVER_CLASS GxEPD2_420     // GDEW042T2   400x300, UC8176 (IL0398)
-//#define GxEPD2_DRIVER_CLASS GxEPD2_420_M01 // GDEW042M01  400x300, UC8176 (IL0398)
+#define GxEPD2_DRIVER_CLASS GxEPD2_420_M01 // GDEW042M01  400x300, UC8176 (IL0398)
 //#define GxEPD2_DRIVER_CLASS GxEPD2_583     // GDEW0583T7  600x448, UC8179 (IL0371)
 //#define GxEPD2_DRIVER_CLASS GxEPD2_583_T8  // GDEW0583T8  648x480, GD7965
 //#define GxEPD2_DRIVER_CLASS GxEPD2_750     // GDEW075T8   640x384, UC8179 (IL0371)
@@ -114,8 +114,10 @@
 // adapt the constructor parameters to your wiring
 #if !IS_GxEPD2_1248(GxEPD2_DRIVER_CLASS)
 #if defined(ARDUINO_LOLIN_D32_PRO)
+#error Wrong constructur
 GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=5*/ EPD_CS, /*DC=*/ 0, /*RST=*/ 2, /*BUSY=*/ 15));
 #elif defined(ARDUINO_ESP32_DEV) // e.g. TTGO T8 ESP32-WROVER
+#error Wrong constructur
 GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=5*/ EPD_CS, /*DC=*/ 2, /*RST=*/ 0, /*BUSY=*/ 4));
 #else
 // moved to epaper.c because of multiple definitions when in header
@@ -124,6 +126,7 @@ GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> displ
 #else // GxEPD2_1248
 // Waveshare 12.48 b/w SPI display board and frame or Good Display 12.48 b/w panel GDEW1248T3
 // general constructor for use with all parameters, e.g. for Waveshare ESP32 driver board mounted on connection board
+#error Wrong constructur
 GxEPD2_BW < GxEPD2_1248, GxEPD2_1248::HEIGHT / 4 > display(GxEPD2_1248(/*sck=*/ 13, /*miso=*/ 12, /*mosi=*/ 14,
     /*cs_m1=*/ 23, /*cs_s1=*/ 22, /*cs_m2=*/ 16, /*cs_s2=*/ 19,
     /*dc1=*/ 25, /*dc2=*/ 17, /*rst1=*/ 33, /*rst2=*/ 5,
@@ -142,6 +145,7 @@ GxEPD2_BW < GxEPD2_1248, GxEPD2_1248::HEIGHT / 4 > display(GxEPD2_1248(/*sck=*/
 #define MAX_HEIGHT(EPD) (EPD::HEIGHT <= (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2) ? EPD::HEIGHT : (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2))
 #endif
 // adapt the constructor parameters to your wiring
+#error Wrong constructur
 GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=4*/ EPD_CS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
 #endif
 
@@ -159,6 +163,7 @@ GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> displ
 #define MAX_HEIGHT(EPD) (EPD::HEIGHT <= (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2) ? EPD::HEIGHT : (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2))
 #endif
 // adapt the constructor parameters to your wiring
+#error Wrong constructur
 GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=*/ EPD_CS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
 #endif
 
@@ -172,6 +177,7 @@ GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> displ
 #define MAX_HEIGHT(EPD) (EPD::HEIGHT <= (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2) ? EPD::HEIGHT : (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2))
 #endif
 // adapt the constructor parameters to your wiring
+#error Wrong constructur
 GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=77*/ EPD_CS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
 #endif
 
@@ -185,6 +191,7 @@ GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> displ
 #define MAX_HEIGHT(EPD) (EPD::HEIGHT <= (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2) ? EPD::HEIGHT : (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2))
 #endif
 // adapt the constructor parameters to your wiring
+#error Wrong constructur
 GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=4*/ 4, /*DC=*/ 7, /*RST=*/ 6, /*BUSY=*/ 5));
 //GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=4*/ 4, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1)); // my Seed XIOA0
 //GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=4*/ 3, /*DC=*/ 2, /*RST=*/ 1, /*BUSY=*/ 0)); // my other Seed XIOA0
@@ -200,6 +207,7 @@ GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> displ
 #define MAX_HEIGHT(EPD) (EPD::HEIGHT <= (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2) ? EPD::HEIGHT : (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2))
 #endif
 // adapt the constructor parameters to your wiring
+#error Wrong constructur
 GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=4*/ EPD_CS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
 #endif
 

include/epaper.h

@@ -1,6 +1,8 @@
 #ifndef EPAPER_H
 #define EPAPER_H
 
+#include "timeseries.h"
+
 #include <GxEPD2_BW.h>
 #include "GxEPD2_display_selection_new_style.h"
 
@@ -9,8 +11,8 @@ typedef void (*epaper_callback)(GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HE
 void epaper_init(void);
 void epaper_test(void);
 
-//void epaper_plot(uint16_t x, uint16_t y, uint16_t w, uint16_t h, timeseries_t *timeseries, uint32_t time_tick_interval);
+void epaper_plot(uint16_t x, uint16_t y, uint16_t w, uint16_t h, timeseries_t *timeseries, uint32_t time_tick_interval);
 
-void epaper_draw_and_hibernate(epaper_callback cb);
+void epaper_draw_and_hibernate(epaper_callback cb, bool full_refresh);
 
 #endif

include/timeseries.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <stdint.h>
+
+#include <vector>
+
+typedef struct {
+    uint64_t tstart, tend, interval;
+    std::vector<float> data;
+    const char *unit;
+    const char *format;
+} timeseries_t;
+
+void timeseries_init(timeseries_t *ts, uint64_t tstart, uint64_t interval, const char *unit, const char *format);
+
+void timeseries_append(timeseries_t *ts, float value);

src/epaper.cpp

@@ -8,11 +8,11 @@
 #include "epaper.h"
 
 static GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)>
-	display(GxEPD2_DRIVER_CLASS(/*CS=5*/ EPD_CS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
+	display(GxEPD2_DRIVER_CLASS(/*CS=*/ 17, /*DC=*/ 18, /*RST=*/ 19, /*BUSY=*/ 22));
 
 void epaper_init(void)
 {
-    display.init();
+	display.init(0, true, 2, false);
 }
 
 void epaper_test(void)
@@ -33,17 +33,24 @@ void epaper_test(void)
 		display.setCursor(x, y);
 		display.print("Hello World!");
 		for(int i = -1; i <= 1; i++) {
-      display.drawCircle(display.width()/2, display.height()/2, tbw*15/10/2+i, GxEPD_RED);
+			display.drawCircle(display.width()/2, display.height()/2, tbw*15/10/2+i, GxEPD_BLACK);
+		}
+
+		display.setCursor(10, FreeMonoBold9pt7b.yAdvance + 10);
+		for(uint16_t c = 0; c < 256; c++) {
+			display.print((char)c);
+
+			if((c % 32) == 31) {
+				display.println();
+			}
 		}
 	}
 	while (display.nextPage());
 
 	Serial.println(F("Init done. Display going to powersave…"));
-
-  display.hibernate();
 }
 
-void epaper_draw_and_hibernate(epaper_callback cb)
+void epaper_draw_and_hibernate(epaper_callback cb, bool full_refresh)
 {
 	display.setRotation(0);
 	display.setFullWindow();
@@ -56,7 +63,6 @@ void epaper_draw_and_hibernate(epaper_callback cb)
 	display.hibernate();
 }
 
-#if 0
 // find minimum and maximum values in a vector. NaN is ignored.
 	template<typename T>
 void minmax(const std::vector<T> &vec, T *min, T *max)
@@ -133,9 +139,9 @@ void epaper_plot(uint16_t x, uint16_t y, uint16_t w, uint16_t h, timeseries_t *t
 	uint16_t label_height = tbh;
 
 	// actual graph area
-  uint16_t plot_x = x + 150;
+	uint16_t plot_x = x + tbw;
 	uint16_t plot_y = y;
-  uint16_t plot_w = w - 150;
+	uint16_t plot_w = w - tbw;
 	uint16_t plot_h = h - label_height - 5;
 
 	// determine vertical tick interval
@@ -242,10 +248,10 @@ void epaper_plot(uint16_t x, uint16_t y, uint16_t w, uint16_t h, timeseries_t *t
 				Serial.print(py);
 				Serial.println(F(")."));*/
 
-      display.drawLine(last_x, last_y, px, py, GxEPD_RED);
+			display.drawLine(last_x, last_y, px, py, GxEPD_BLACK);
 
 			// draw it again, 1px below, to give it more weight
-      display.drawLine(last_x, last_y+1, px, py+1, GxEPD_RED);
+			display.drawLine(last_x, last_y+1, px, py+1, GxEPD_BLACK);
 		} else {
 			//Serial.println(F("First point, not drawn."));
 			firstpoint = false;
@@ -254,40 +260,4 @@ void epaper_plot(uint16_t x, uint16_t y, uint16_t w, uint16_t h, timeseries_t *t
 		last_x = px;
 		last_y = py;
 	}
-
-  /* Draw large current value + unit */
-
-  size_t cur_val_idx = timeseries->data.size() - 1;
-  while((cur_val_idx > 0) && isnan(timeseries->data[cur_val_idx])) {
-    cur_val_idx--;
 }
-
-  float current_value = timeseries->data[cur_val_idx];
-
-  display.setFont(&din1451e24pt7b);
-  display.setTextColor(GxEPD_RED);
-
-  char fmt[16];
-
-  snprintf(fmt, sizeof(fmt), "%s %%s", timeseries->format);
-  snprintf(s, sizeof(s), fmt, current_value, timeseries->unit);
-
-  display.getTextBounds(s, 0, 0, &tbx, &tby, &tbw, &tbh);
-
-  display.setCursor(plot_x - tbw - 35, plot_y + plot_h/2 - tby - tbh/2 - 5);
-  display.print(s);
-
-  uint16_t large_text_height = tbh;
-
-  time_t t = timeseries->tstart + trange * cur_val_idx / timeseries->data.size();
-  tm *gmt = gmtime(&t);
-  strftime(s, sizeof(s), "%Y-%m-%d %H:%M", gmt);
-
-  display.setFont(&Org_01);
-
-  display.getTextBounds(s, 0, 0, &tbx, &tby, &tbw, &tbh);
-
-  display.setCursor(plot_x - tbw - 35, plot_y + plot_h/2 - tby + large_text_height/2 + 5);
-  display.print(s);
-}
-#endif

src/main.cpp

@@ -1,12 +1,26 @@
 #include <Arduino.h>
 #include <Adafruit_SCD30.h>
 
+#include <Adafruit_GFX.h>
+#include <Fonts/FreeSans9pt7b.h>
+#include <Fonts/FreeSans12pt7b.h>
+#include <Fonts/FreeSansBold12pt7b.h>
+
 #include <epaper.h>
 
 Adafruit_SCD30  scd30;
 
+static timeseries_t ts_scd30_co2, ts_scd30_temperature, ts_scd30_humidity;
+
+#define REF_ALTITUDE 320   // meters
+#define REF_CO2_PPM  425   // clean air according to DWD at 2024-06-17
+
 void initSCD30(void)
 {
+	timeseries_init(&ts_scd30_co2, 0, 15, "ppm", "%.1f");
+	timeseries_init(&ts_scd30_temperature, 0, 15, "°C", "%.1f");
+	timeseries_init(&ts_scd30_humidity, 0, 15, "%", "%.1f");
+
 	// Try to initialize!
 	if (!scd30.begin()) {
 		Serial.println("scd30: Failed to find SCD30 chip");
@@ -14,6 +28,7 @@ void initSCD30(void)
 	}
 	Serial.println("scd30: SCD30 Found!");
 
+	// TODO: check what this actually resets. Maybe also the calibration?
 	scd30.reset();
 
 	if (!scd30.setMeasurementInterval(15)){ // seconds
@@ -24,6 +39,32 @@ void initSCD30(void)
 	Serial.print(scd30.getMeasurementInterval()); 
 	Serial.println(" seconds");
 
+	uint16_t pressureOffset = scd30.getAmbientPressureOffset();
+	uint16_t altitudeOffset = scd30.getAltitudeOffset();
+	bool selfCalEnabled = scd30.selfCalibrationEnabled();
+
+	if(altitudeOffset != REF_ALTITUDE) {
+		Serial.println("scd30: updating altitude offset.");
+		if(!scd30.setAltitudeOffset(REF_ALTITUDE)) {
+			Serial.println("scd30: failed to set altitude offset!");
+		}
+		altitudeOffset = REF_ALTITUDE;
+	}
+
+	if(selfCalEnabled) {
+		Serial.println("scd30: self calibration was enabled -> disabling.");
+		scd30.selfCalibrationEnabled(false);
+	}
+
+	Serial.println("scd30: offset readout:");
+	Serial.print("  Pressure: ");
+	Serial.print(pressureOffset);
+	Serial.println(" mbar");
+	Serial.print("  Altitude: ");
+	Serial.print(altitudeOffset);
+	Serial.println(" m");
+	Serial.println();
+
 	if(!scd30.startContinuousMeasurement()) {
 		Serial.println("scd30: Could not start continuous measurement");
 	}
@@ -32,20 +73,113 @@ void initSCD30(void)
 
 void setup(void)
 {
+	Serial.begin(115200);
+	Serial.println("Hello World!");
+
+	delay(3000);
+
 	initSCD30();
 	epaper_init();
 	epaper_test();
 }
 
 
+void draw_epaper_callback(GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> *display)
+{
+	display->setRotation(1);
+	display->setTextColor(GxEPD_BLACK);
+
+	int16_t y = FreeSans12pt7b.yAdvance;
+
+	// first line: CO₂
+	display->setCursor(0, y);
+
+	display->setFont(&FreeSans12pt7b);
+	display->print("CO");
+
+	display->setFont(&FreeSans9pt7b);
+	display->print("2");
+
+	display->setFont(&FreeSans12pt7b);
+	display->print(": ");
+
+	y += FreeSans12pt7b.yAdvance;
+	display->setCursor(0, y);
+
+	display->setFont(&FreeSansBold12pt7b);
+	display->print(scd30.CO2, 2);
+
+	display->setFont(&FreeSans12pt7b);
+	display->print(" ppm");
+
+	epaper_plot(150, 5, 150, 65, &ts_scd30_co2, 900);
+
+	// second line: temperature
+	y = 75 + FreeSans12pt7b.yAdvance;
+	display->setCursor(0, y);
+
+	display->setFont(&FreeSans12pt7b);
+	display->print("Temp.: ");
+
+	y += FreeSans12pt7b.yAdvance;
+	display->setCursor(0, y);
+
+	display->setFont(&FreeSansBold12pt7b);
+	display->print(scd30.temperature, 2);
+
+	display->setFont(&FreeSans12pt7b);
+	display->print(" ");
+
+	// cheat a bit for the ° character
+	uint16_t stored_baseline_y = display->getCursorY();
+	uint16_t cursor_x = display->getCursorX();
+
+	display->setCursor(cursor_x, stored_baseline_y - FreeSans12pt7b.yAdvance/4);
+	display->print("o");
+
+	cursor_x = display->getCursorX();
+	display->setCursor(cursor_x, stored_baseline_y);
+	display->print("C");
+
+	epaper_plot(150, 80, 150, 65, &ts_scd30_temperature, 900);
+
+	// second line: Humidity
+	y = 150 + FreeSans12pt7b.yAdvance;
+	display->setCursor(0, y);
+
+	display->setCursor(0, y);
+
+	display->setFont(&FreeSans12pt7b);
+	display->print("Feuchte: ");
+
+	y += FreeSans12pt7b.yAdvance;
+	display->setCursor(0, y);
+
+	display->setFont(&FreeSansBold12pt7b);
+	display->print(scd30.relative_humidity, 1);
+
+	display->setFont(&FreeSans12pt7b);
+	display->print(" %rH");
+
+	epaper_plot(150, 155, 150, 65, &ts_scd30_humidity, 900);
+}
+
 void loop(void)
 {
+	static bool calibrationDone = true; // change to false to recalibrate at REF_CO2_PPM
+	static uint32_t lastEPaperRefresh = 0;
+	uint32_t now = millis();
+
 	if(scd30.dataReady()) {
 		if (!scd30.read()) {
-			Serial.println("Error reading sensor data");
+			Serial.println("scd30: Error reading sensor data");
 			return;
 		}
 
+		timeseries_append(&ts_scd30_co2, scd30.CO2);
+		timeseries_append(&ts_scd30_temperature, scd30.temperature);
+		timeseries_append(&ts_scd30_humidity, scd30.relative_humidity);
+
 		Serial.print("CO2: ");
 		Serial.print(scd30.CO2, 3);
 		Serial.println(" ppm");
@@ -56,6 +190,24 @@ void loop(void)
 		Serial.print(scd30.relative_humidity, 2);
 		Serial.println(" %");
 		Serial.println("");
+
+		if((now - lastEPaperRefresh) >= 60000) {
+			lastEPaperRefresh = now;
+			epaper_draw_and_hibernate(draw_epaper_callback, false);
+		}
+
+		if(!calibrationDone && now >= 300000) {
+			uint16_t calValue = scd30.getForcedCalibrationReference();
+
+			if(calValue != REF_CO2_PPM) {
+				Serial.println("scd30: Setting calibration reference value.");
+				if(!scd30.forceRecalibrationWithReference(REF_CO2_PPM)) {
+					Serial.println("scd30: Recalibration failed!");
+				}
+			}
+
+			calibrationDone = true;
+		}
 	}
 
 	delay(1000);

src/timeseries.cpp

@@ -0,0 +1,18 @@
+#include "timeseries.h"
+
+
+void timeseries_init(timeseries_t *ts, uint64_t tstart, uint64_t interval, const char *unit, const char *format)
+{
+	ts->tstart = tstart;
+	ts->tend = tstart;
+	ts->interval = interval;
+	ts->unit = unit;
+	ts->format = format;
+}
+
+
+void timeseries_append(timeseries_t *ts, float value)
+{
+	ts->data.push_back(value);
+	ts->tend += ts->interval;
+}