pax curve plotter (experimental)

README.md

@@ -150,7 +150,13 @@ Paxcounter generates identifiers for sniffed MAC adresses and collects them temp
 
 # Display
 
-If you're using a device with OLED display, or if you add such one to the I2C bus, the device shows live data on the display. You can flip between pages showing pax, time, GPS and BME sensor data by pressing the button of the device.
+If you're using a device with OLED display, or if you add such one to the I2C bus, the device shows live data on the display. You can flip display pages showing 
+- recent count of pax
+- histogram
+- GPS data
+- BME sensor data
+- Time of day 
+by pressing the button of the device.
 
 # Sensors and Peripherals
 

include/display.h

@@ -7,10 +7,17 @@
 extern uint8_t DisplayIsOn;
 
 void refreshTheDisplay(bool nextPage = false);
-void init_display(void);
+void init_display(uint8_t verbose = 0);
 void draw_page(time_t t, uint8_t page);
-void dp_printf(int x, int y, int font, int inv, const char *format, ...);
+void dp_printf(uint16_t x, uint16_t y, uint8_t font, uint8_t inv,
-void dp_printqr(int offset_x, int offset_y, const char *Message);
+               const char *format, ...);
-void oledfillRect(int x, int y, int width, int height, int bRender);
+void dp_printqr(uint16_t offset_x, uint16_t offset_y, const char *Message);
+void oledfillRect(uint16_t x, uint16_t y, uint16_t width, uint16_t height,
+                  uint8_t bRender);
+void oledScrollBufferLeft(uint8_t *buf, const uint16_t width,
+                          const uint16_t height);
+int oledDrawPixel(uint8_t *buf, const uint16_t x, const uint16_t y,
+                  const uint8_t dot);
+void oledPlotCurve(uint16_t count);
 
 #endif

src/display.cpp

@@ -37,23 +37,29 @@ FONT_STRETCHED: 16x32px = 8 chars / line
 // local Tag for logging
 static const char TAG[] = __FILE__;
 
+#define DISPLAY_PAGES (5) // number of paxcounter display pages
+
 // settings for oled display library
-#define DISPLAY_PAGES (4) // number of display pages
+#define USE_BACKBUFFER
-#define USE_BACKBUFFER    // for display library
 
 // settings for qr code generator
 #define QR_VERSION 3     // 29 x 29px
 #define QR_SCALEFACTOR 2 // 29 -> 58x < 64px
 
-// helper arry for converting month values to text
+// settings for curve plotter
+#define PLOT_SCALEFACTOR 1 // downscales pax numbers to display rows
+#define DISPLAY_WIDTH 128  // Width in pixels of OLED-display, must be 32X
+#define DISPLAY_HEIGHT 64  // Height in pixels of OLED-display, must be 16X
+
+// helper array for converting month values to text
 const char *printmonth[] = {"xxx", "Jan", "Feb", "Mar", "Apr", "May", "Jun",
                             "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
-
 uint8_t DisplayIsOn = 0;
+uint8_t displaybuf[DISPLAY_WIDTH * DISPLAY_HEIGHT / 8] = {0};
 
 QRCode qrcode;
 
-void init_display(void) {
+void init_display(uint8_t verbose) {
 
   // block i2c bus access
   if (!I2C_MUTEX_LOCK())
@@ -71,6 +77,8 @@ void init_display(void) {
     oledSetContrast(DISPLAYCONTRAST);
     oledFill(0, 1);
 
+    if (verbose) {
+
       // show startup screen
       // to come -> display .bmp file with logo
 
@@ -87,7 +95,8 @@ void init_display(void) {
                 (chip_info.features & CHIP_FEATURE_BLE) ? "/BLE" : "");
       dp_printf(0, 6, 0, 0, "%dMB %s Flash",
                 spi_flash_get_chip_size() / (1024 * 1024),
-              (chip_info.features & CHIP_FEATURE_EMB_FLASH) ? "int." : "ext.");
+                (chip_info.features & CHIP_FEATURE_EMB_FLASH) ? "int."
+                                                              : "ext.");
 
       // give user some time to read or take picture
       oledDumpBuffer(NULL);
@@ -121,6 +130,8 @@ void init_display(void) {
       oledFill(0x00, 1);
 #endif // HAS_LORA
 
+    } // verbose
+
     oledPower(cfg.screenon); // set display off if disabled
 
     I2C_MUTEX_UNLOCK(); // release i2c bus access
@@ -171,15 +182,20 @@ void draw_page(time_t t, uint8_t page) {
 
   // line 1/2: pax counter
   dp_printf(0, 0, FONT_STRETCHED, 0, "PAX:%-4d",
-            (int)macs.size()); // display number of unique macs total Wifi + BLE
+            macs.size()); // display number of unique macs total Wifi + BLE
+
+  // update histogram if we have a display
+  oledPlotCurve(macs.size());
 
   switch (page % DISPLAY_PAGES) {
 
     // page 0: parameters overview
-    // page 1: time
+    // page 1: pax graph
     // page 2: GPS
     // page 3: BME280/680
+    // page 4: time
 
+    // page 0: parameters overview
   case 0:
 
     // line 3: wifi + bluetooth counters
@@ -194,7 +210,9 @@ void draw_page(time_t t, uint8_t page) {
 // line 4: Battery + GPS status + Wifi channel
 #if (defined BAT_MEASURE_ADC || defined HAS_PMU)
     if (batt_voltage == 0xffff)
-      dp_printf(0, 4, FONT_SMALL, 0, "%s", "B:USB  ");
+      dp_printf(0, 4, FONT_SMALL, 0, "%s", "USB    ");
+    else if (batt_voltage == 0)
+      dp_printf(0, 4, FONT_SMALL, 0, "%s", "No batt");
     else
       dp_printf(0, 4, FONT_SMALL, 0, "B:%.2fV", batt_voltage / 1000.0);
 #endif
@@ -249,11 +267,12 @@ void draw_page(time_t t, uint8_t page) {
 
     break; // page0
 
+    // page 1: pax graph
   case 1:
-    dp_printf(0, 4, FONT_LARGE, 0, "%02d:%02d:%02d", hour(t), minute(t),
+    oledDumpBuffer(displaybuf);
-              second(t));
     break; // page1
 
+    // page 2: GPS
   case 2:
 #if (HAS_GPS)
     if (gps.location.age() < 1500) {
@@ -281,6 +300,7 @@ void draw_page(time_t t, uint8_t page) {
 
     break; // page2
 
+    // page 3: BME280/680
   case 3:
 
 #if (HAS_BME)
@@ -301,6 +321,13 @@ void draw_page(time_t t, uint8_t page) {
 
     break; // page3
 
+  // page 4: time
+  case 4:
+
+    dp_printf(0, 4, FONT_LARGE, 0, "%02d:%02d:%02d", hour(t), minute(t),
+              second(t));
+    break;
+
   default:
     break; // default
 
@@ -308,8 +335,9 @@ void draw_page(time_t t, uint8_t page) {
 
 } // draw_page
 
-// display print helper functions
+// display helper functions
-void dp_printf(int x, int y, int font, int inv, const char *format, ...) {
+void dp_printf(uint16_t x, uint16_t y, uint8_t font, uint8_t inv,
+               const char *format, ...) {
   char loc_buf[64];
   char *temp = loc_buf;
   va_list arg;
@@ -337,13 +365,13 @@ void dp_printf(int x, int y, int font, int inv, const char *format, ...) {
   }
 }
 
-void dp_printqr(int offset_x, int offset_y, const char *Message) {
+void dp_printqr(uint16_t offset_x, uint16_t offset_y, const char *Message) {
   uint8_t qrcodeData[qrcode_getBufferSize(QR_VERSION)];
   qrcode_initText(&qrcode, qrcodeData, QR_VERSION, ECC_HIGH, Message);
 
   // draw QR code
-  for (int y = 0; y < qrcode.size; y++)
+  for (uint16_t y = 0; y < qrcode.size; y++)
-    for (int x = 0; x < qrcode.size; x++)
+    for (uint16_t x = 0; x < qrcode.size; x++)
       if (!qrcode_getModule(&qrcode, x, y)) // "black"
         oledfillRect(x * QR_SCALEFACTOR + offset_x,
                      y * QR_SCALEFACTOR + offset_y, QR_SCALEFACTOR,
@@ -360,9 +388,71 @@ void dp_printqr(int offset_x, int offset_y, const char *Message) {
                qrcode.size * QR_SCALEFACTOR + 2 * offset_y, false);
 }
 
-void oledfillRect(int x, int y, int width, int height, int bRender) {
+void oledfillRect(uint16_t x, uint16_t y, uint16_t width, uint16_t height,
-  for (int xi = x; xi < x + width; xi++)
+                  uint8_t bRender) {
+  for (uint16_t xi = x; xi < x + width; xi++)
     oledDrawLine(xi, y, xi, y + height - 1, bRender);
 }
 
+int oledDrawPixel(uint8_t *buf, const uint16_t x, const uint16_t y,
+                  const uint8_t dot) {
+
+  uint8_t page, bit;
+
+  if (x > DISPLAY_WIDTH || y > DISPLAY_HEIGHT)
+    return -1;
+
+  page = y / 8;
+  bit = y % 8;
+
+  if (dot)
+    buf[page * DISPLAY_WIDTH + x] |= (1 << bit); // mark
+  else
+    buf[page * DISPLAY_WIDTH + x] &= ~(0 << bit); // clear
+
+  return 0;
+}
+
+void oledScrollBufferLeft(uint8_t *buf, const uint16_t width,
+                          const uint16_t height) {
+
+  uint16_t col, page, idx;
+
+  for (page = 0; page < height / 8; page++) {
+    for (col = 0; col < width - 1; col++) {
+      idx = page * width + col;
+      buf[idx] = buf[idx + 1];
+    }
+    buf[idx + 1] = 0;
+  }
+}
+
+void oledPlotCurve(uint16_t count) {
+
+  uint8_t level;
+  static uint16_t last_count = 0, col = 0, row = 0;
+
+  if (last_count == count)
+    return;
+
+  // next count cycle?
+  if (count == 0) {
+
+    // matrix full? then scroll left 1 dot, else increment column
+    if (col < DISPLAY_WIDTH - 1)
+      col++;
+    else
+      oledScrollBufferLeft(displaybuf, DISPLAY_WIDTH, DISPLAY_HEIGHT);
+
+  } else
+    oledDrawPixel(displaybuf, col, row, 0); // clear current dot
+
+  // scale and set new dot
+  last_count = count;
+  level = count / PLOT_SCALEFACTOR;
+  row =
+      level <= DISPLAY_HEIGHT ? DISPLAY_HEIGHT - 1 - level % DISPLAY_HEIGHT : 0;
+  oledDrawPixel(displaybuf, col, row, 1);
+}
+
 #endif // HAS_DISPLAY