A simple meter using Adafruit 2.8 TFT with touch v2

Dependencies:   SPI_STMPE610 UniGraphic mbed vt100

/media/uploads/Rhyme/tester_s.jpg

A dumb simple voltage tester using ADC.
With FRDM-KL25Z, you can measure about 0V to 3.28V.
Nothing to drop your jaw nor holding your breath
but I wanted one, so I wrote one ;-)

とても単純はADCを使用した電圧テスターです。
FRDM-KL25Z を使用した場合、0V ~ 3.28V くらいが測定範囲です。
特に目新しいことも、驚くこともありませんが、
自分が欲しいので書いてみました (^ - ^)

On 18-May-2018 
I changed the number display from 0.00 to 0.000
so that I can measure the change of a small loadcell.

2018年5月18日 
ロードセル (重量センサ)の出力値の変化を見たかったので
有効数字を小数点以下2桁から3桁に変更しました。

Revision:
0:d01def9cf41e
Child:
1:d7f2aa328962
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/meter.cpp	Thu Jul 20 02:37:13 2017 +0000
@@ -0,0 +1,149 @@
+#include "mbed.h"
+#include <math.h>
+#include <string.h>
+#include "ILI9341.h"
+#include "Arial12x12.h"
+#include "Arial24x23.h"
+#include "Arial28x28.h"
+#include "Arial43x48_numb.h"
+#include "SPI_STMPE610.h"
+#include "meter.h"
+#include "vt100.h"
+#include "main.h"
+
+#ifndef M_PI
+#define M_PI 3.141593
+#endif
+
+extern vt100        *tty ;
+extern ILI9341      *tft ;
+extern SPI_STMPE610 *tsc ;
+extern meter        *tacho ;
+double SIN[451] ;
+double COS[451] ;
+
+static void fillTriTable(void)
+{
+    double theta ;
+    int i ;
+    for (i = 1 ; i < 450 ; i++ ) {
+        theta = M_PI * (((double)(i + 450))/1800.0) ;
+        SIN[i] = sin( theta ) ;
+        COS[i] = cos( theta ) ;
+    }
+    SIN[0] = 0.0 ;
+    COS[0] = 1.0 ;
+    SIN[450] = 1.0 ;
+    COS[450] = 0.0 ;
+}
+
+meter::meter(int x, int y, int width, int height, float min, float max) 
+{
+    _x = x ;
+    _y = y ;
+    _w = width ;
+    _h = height ;
+    _value = min ;
+    _min = min ;
+    _max = max ;
+    _center_x = _x + _w / 2 ;
+    _center_y = _y + (2 * _h) / 3 ;
+    fillTriTable() ;
+}
+
+meter::~meter(void) 
+{
+}
+
+void meter::drawFrame(void)
+{
+    tft->BusEnable(true) ;
+    tft->fillrect(_x, _y, _x+ _w - 1, _y+(2 * _h)/3 - 1, White) ;
+    tft->fillrect(_x, _y+(2 * _h)/3 - 1, _x + _w - 1, _y + _h - 1, Black) ;
+    tft->rect(_x, _y, _x + _w - 1, _y + _h - 1, Green) ;
+    tft->BusEnable(false) ;
+}
+
+void meter::drawScale(void)
+{
+    int x1, x2, y1, y2 ;
+    double radius ;
+    double append ;
+    radius = _w / 2.0 ;
+    tft->BusEnable(true) ;
+    for (int i = 0 ; i < 450 ; i += 45 ) {
+        x1 = (radius * COS[i] + 0.5) ;
+        y1 = (radius * SIN[i] + 0.5) ;
+        if ((i % 10) == 5) {
+            append = 5 ;
+        } else {
+            append = 10 ;
+        }
+        x2 = ((radius + append) * COS[i] + 0.5) ;
+        y2 = ((radius + append) * SIN[i] + 0.5) ;
+        tft->line(_center_x + x1, _center_y - y1, _center_x + x2, _center_y - y2, Black) ;
+        tft->line(_center_x - x1, _center_y - y1, _center_x - x2, _center_y - y2, Black) ;
+    }
+    tft->line(_center_x, _center_y - radius, _center_x, _center_y - (radius + 10), Black) ;
+    tft->BusEnable(false) ;
+}
+
+void meter::drawHand(float value)
+{
+    static int prev_x1 = 0, prev_x2 = 0, prev_y1 = 0, prev_y2 = 0 ;
+    int x1, x2, y1, y2 ;
+    double theta ;
+    double radius = _w / 20.0 ;
+    double append = 8.0 * (_w / 20.0)  ;
+    int i ;
+    
+    theta = 90.0 - (90.0 * (value / _max)) ;
+    if (theta > 45.0) {
+        i = (10.0 * (90.0 - theta + 45.0) + 0.5) ; 
+        x1 = _center_x -(radius * COS[i-450] + 0.5) ;
+        x2 = _center_x -((radius + append) * COS[i-450] + 0.5) ;
+    } else {
+        i = (10.0 * (theta + 45.0) + 0.5) ;
+        x1 = _center_x + (radius * COS[i-450] + 0.5) ;
+        x2 = _center_x + ((radius + append) * COS[i-450] + 0.5) ;
+    }
+    y1 = _center_y - (radius * SIN[i-450] + 0.5) ;
+    y2 = _center_y - ((radius + append) * SIN[i-450] + 0.5) ;
+    tft->BusEnable(true) ;
+    tft->line(prev_x1, prev_y1, prev_x2, prev_y2, White) ;
+    tft->line(x1, y1, x2, y2, Black) ;
+    tft->BusEnable(false) ;
+    prev_x1 = x1 ;
+    prev_x2 = x2 ;
+    prev_y1 = y1 ;
+    prev_y2 = y2 ;
+}
+
+void meter::draw(void) 
+{
+}
+
+void meter::draw(float value) 
+{
+    tft->BusEnable(true) ;
+    drawHand(_value) ;
+    tft->BusEnable(false) ;
+}
+
+void meter::drawValue(float value)
+{
+    char str[32] ;
+    int v1, v2 ;
+    v1 = (int)value ;
+    v2 = ((int)(100.0 * value) % 100) ;
+    sprintf(str, "%d.%02d V", v1, v2) ;
+    tft->BusEnable(true) ;
+    tft->locate(80, 190) ;
+    tft->printf(str) ;
+    wait(0.01) ;
+    tft->BusEnable(false) ;
+}
+
+void meter::update(float value) 
+{
+}
\ No newline at end of file