From 3df5993c0a539afddf620d913b153938e8576211 Mon Sep 17 00:00:00 2001
From: Karai Csaba <cskarai@freemail.hu>
Date: Fri, 20 May 2016 07:38:07 +0200
Subject: [PATCH] VoltagePage implementation

---
 .../arduino/EspLinkSample/EspLinkSample.ino   |   4 +
 examples/arduino/EspLinkSample/Pages.h        |   4 +
 .../arduino/EspLinkSample/VoltagePage.ino     | 127 ++++++++++++++++++
 3 files changed, 135 insertions(+)
 create mode 100644 examples/arduino/EspLinkSample/VoltagePage.ino

diff --git a/examples/arduino/EspLinkSample/EspLinkSample.ino b/examples/arduino/EspLinkSample/EspLinkSample.ino
index 57d7e14..ee47a9d 100644
--- a/examples/arduino/EspLinkSample/EspLinkSample.ino
+++ b/examples/arduino/EspLinkSample/EspLinkSample.ino
@@ -3,10 +3,12 @@
 
 const char ledURL[] PROGMEM = "/LED.html.json";
 const char userURL[] PROGMEM = "/User.html.json";
+const char voltageURL[] PROGMEM = "/Voltage.html.json";
 
 const WebMethod PROGMEM methods[] = {
   { ledURL, ledHtmlCallback },
   { userURL, userHtmlCallback },
+  { voltageURL, voltageHtmlCallback },
   { NULL, NULL },
 };
 
@@ -19,6 +21,7 @@ void setup()
 
   ledInit();
   userInit();
+  voltageInit();
 }
 
 void loop()
@@ -26,5 +29,6 @@ void loop()
   webServer.loop();
 
   ledLoop();
+  voltageLoop();
 }
 
diff --git a/examples/arduino/EspLinkSample/Pages.h b/examples/arduino/EspLinkSample/Pages.h
index 6142f36..7043b9d 100644
--- a/examples/arduino/EspLinkSample/Pages.h
+++ b/examples/arduino/EspLinkSample/Pages.h
@@ -8,6 +8,10 @@ void ledInit();
 void userHtmlCallback(WebServerCommand command, char * data, int dataLen);
 void userInit();
 
+void voltageHtmlCallback(WebServerCommand command, char * data, int dataLen);
+void voltageLoop();
+void voltageInit();
+
 #endif /* PAGES_H */
 
 
diff --git a/examples/arduino/EspLinkSample/VoltagePage.ino b/examples/arduino/EspLinkSample/VoltagePage.ino
new file mode 100644
index 0000000..68f9aa3
--- /dev/null
+++ b/examples/arduino/EspLinkSample/VoltagePage.ino
@@ -0,0 +1,127 @@
+#include "WebServer.h"
+
+#include <avr/io.h>
+
+#define SAMPLE_COUNT 100
+#define PERIOD_COUNT (135 * SAMPLE_COUNT)
+
+uint16_t smin = 0xFFFF;
+uint16_t smax = 0;
+uint32_t savg = 0;
+
+uint16_t count;
+uint32_t voltage = 0;
+uint16_t measured_voltage = 0;
+
+#define MAX_HISTORY 3
+
+uint8_t history_cnt = 0;
+uint32_t h_ts[MAX_HISTORY];
+uint16_t h_min[MAX_HISTORY];
+uint16_t h_max[MAX_HISTORY];
+uint16_t h_avg[MAX_HISTORY];
+
+uint16_t calibrate = 0x128; // calibrate this manually
+
+void voltageInit()
+{
+  analogReference(DEFAULT);
+
+  count = 0;
+}
+
+void voltageLoop()
+{
+  uint16_t adc = analogRead(A0);    
+
+  if( adc < smin )
+    smin = adc;
+  if( adc > smax )
+    smax = adc;
+  savg += adc;
+  
+  voltage += adc;
+  count++;
+
+  if( (count % SAMPLE_COUNT) == 0 )
+  {
+    voltage /= SAMPLE_COUNT;
+    measured_voltage = voltage * calibrate / 256;
+    voltage = 0;
+  }
+  if( count == PERIOD_COUNT )
+  {
+    for(int8_t i=MAX_HISTORY-2; i >=0; i-- )
+    {
+      h_ts[i+1] = h_ts[i];
+      h_min[i+1] = h_min[i];
+      h_max[i+1] = h_max[i];
+      h_avg[i+1] = h_avg[i];
+    }
+
+    h_ts[0] = millis();
+    h_min[0] = (uint32_t)smin * calibrate / 256;
+    h_max[0] = (uint32_t)smax * calibrate / 256;
+    h_avg[0] = (savg / PERIOD_COUNT) * calibrate / 256;
+
+    smin = 0xFFFF;
+    smax = 0;
+    savg = 0;
+
+    if( history_cnt < MAX_HISTORY )
+      history_cnt++;
+    count = 0;
+  }
+}
+
+void voltageHtmlCallback(WebServerCommand command, char * data, int dataLen)
+{
+  switch(command)
+  {
+    case BUTTON_PRESS:
+      // no buttons
+      break;   
+    case SET_FIELD:
+      /* TODO */
+      break;
+    case LOAD:
+    case REFRESH:
+      {
+        webServer.setArgNum(2);
+
+        char buf[20];
+        uint8_t int_part = measured_voltage / 256;
+        uint8_t float_part = ((measured_voltage & 255) * 100) / 256;
+        sprintf(buf, "%d.%02d V", int_part, float_part);
+        webServer.setArgString("voltage", buf);
+
+        char tab[256];
+        tab[0] = 0;
+        strcat_P(tab, PSTR("[[\"Time\",\"Min\",\"AVG\",\"Max\"]"));
+
+        for(uint8_t i=0; i < history_cnt; i++ )
+        {
+          uint8_t min_i = h_min[i] / 256;
+          uint8_t min_f = ((h_min[i] & 255) * 100) / 256;
+          uint8_t max_i = h_max[i] / 256;
+          uint8_t max_f = ((h_max[i] & 255) * 100) / 256;
+          uint8_t avg_i = h_avg[i] / 256;
+          uint8_t avg_f = ((h_avg[i] & 255) * 100) / 256;
+
+          sprintf(buf, ",[\"%d s\",", h_ts[i] / 1000);
+          strcat(tab, buf);
+          sprintf(buf, "\"%d.%02d V\",", min_i, min_f);
+          strcat(tab, buf);
+          sprintf(buf, "\"%d.%02d V\",", avg_i, avg_f);
+          strcat(tab, buf);
+          sprintf(buf, "\"%d.%02d V\"]", max_i, max_f);
+          strcat(tab, buf);
+        }
+
+        strcat_P(tab, PSTR("]"));
+        webServer.setArgJson("table", tab);
+      }
+      break;
+  }
+}
+