CQ Publishing / Mbed 2 deprecated tg_201410s7_lcrmeter

Transistor Gijutsu, October 2014, Special Features Chapter 7，Software of the LCRmeter トランジスタ技術2014年10月号　特集第7章のソフトウェア,サバイバルLCRメータ

Dependencies:   mbed

main.cpp@0:b3e41ec91adf, 2014-08-28 (annotated)

Committer:
Dance
Date:
Thu Aug 28 07:09:42 2014 +0000
Revision:
0:b3e41ec91adf
????????2014?10?????7????????

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Dance 0:b3e41ec91adf 1 //
Dance 0:b3e41ec91adf 2 // Transistor Gijutu - LPC11U35 ARM Writer
Dance 0:b3e41ec91adf 3 // LCR meter
Dance 0:b3e41ec91adf 4 //
Dance 0:b3e41ec91adf 5 #include "mbed.h"
Dance 0:b3e41ec91adf 6 #include "parts.h"
Dance 0:b3e41ec91adf 7
Dance 0:b3e41ec91adf 8 #include "lcd_P4bit.h"
Dance 0:b3e41ec91adf 9
Dance 0:b3e41ec91adf 10 #define IPC 25 // interrupt per cycle
Dance 0:b3e41ec91adf 11 #define PI 3.14159265358979
Dance 0:b3e41ec91adf 12
Dance 0:b3e41ec91adf 13 int ps1k = 0; // pre-scaler for measure freq.
Dance 0:b3e41ec91adf 14 int sintable[] = { 8, 9, 11, 12, 13, 14, 14, 14, 14, 13, 12, 10, 8, 7, 5, 3, 2, 1, 1, 1, 1, 2, 3, 4, 6 };
Dance 0:b3e41ec91adf 15 double Vraw[IPC], Iraw[IPC]; // AD convert data
Dance 0:b3e41ec91adf 16 int VorI;
Dance 0:b3e41ec91adf 17 double vcalc[IPC], icalc[IPC]; // waveform buffer for calc.
Dance 0:b3e41ec91adf 18
Dance 0:b3e41ec91adf 19 Ticker f25k; // interval timer - make sine wave and measure current and voltage
Dance 0:b3e41ec91adf 20
Dance 0:b3e41ec91adf 21 DigitalOut sine0(P0_14); // R2R DAC bit 0
Dance 0:b3e41ec91adf 22 DigitalOut sine1(P0_2); // R2R DAC bit 1
Dance 0:b3e41ec91adf 23 DigitalOut sine2(P0_23); // R2R DAC bit 2
Dance 0:b3e41ec91adf 24 DigitalOut sine3(P0_17); // R2R DAC bit 3
Dance 0:b3e41ec91adf 25 DigitalOut ISRflag(P0_20); // interrupt service routine flag
Dance 0:b3e41ec91adf 26
Dance 0:b3e41ec91adf 27 AnalogIn Voltage(p20); // Voltage ADC
Dance 0:b3e41ec91adf 28 AnalogIn Current(p19); // Current ADC
Dance 0:b3e41ec91adf 29
Dance 0:b3e41ec91adf 30 // 50KHz interval interrupt
Dance 0:b3e41ec91adf 31 void interval_25k() {
Dance 0:b3e41ec91adf 32 ISRflag = 1;
Dance 0:b3e41ec91adf 33 ++ ps1k;
Dance 0:b3e41ec91adf 34 if( IPC <= ps1k ) {
Dance 0:b3e41ec91adf 35 ps1k = 0;
Dance 0:b3e41ec91adf 36 VorI = !VorI;
Dance 0:b3e41ec91adf 37 }
Dance 0:b3e41ec91adf 38 sine0 = sintable[ps1k] & 0x01; // DAC output - each bit
Dance 0:b3e41ec91adf 39 sine1 = sintable[ps1k] & 0x02;
Dance 0:b3e41ec91adf 40 sine2 = sintable[ps1k] & 0x04;
Dance 0:b3e41ec91adf 41 sine3 = sintable[ps1k] & 0x08;
Dance 0:b3e41ec91adf 42 //
Dance 0:b3e41ec91adf 43 if( VorI ) Vraw[ps1k] = Voltage.read(); // measure Voltage or Current
Dance 0:b3e41ec91adf 44 else Iraw[ps1k] = Current.read();
Dance 0:b3e41ec91adf 45 ISRflag = 0;
Dance 0:b3e41ec91adf 46 }
Dance 0:b3e41ec91adf 47
Dance 0:b3e41ec91adf 48 int main() {
Dance 0:b3e41ec91adf 49 int i;
Dance 0:b3e41ec91adf 50 char s[10];
Dance 0:b3e41ec91adf 51 double vi, vq, ii, iq; // voltage/current, in-phase,quad-phase -> vi + jvq, ii + jiq
Dance 0:b3e41ec91adf 52 double r, x; // register, reactance -> r + jx
Dance 0:b3e41ec91adf 53 double a; // amplitude
Dance 0:b3e41ec91adf 54
Dance 0:b3e41ec91adf 55 // work area initialize
Dance 0:b3e41ec91adf 56 VorI = 0;
Dance 0:b3e41ec91adf 57 for( i = 0; IPC > i; i ++ ) Vraw[i] = Iraw[i] = 0.0;
Dance 0:b3e41ec91adf 58 // LCD module initialize
Dance 0:b3e41ec91adf 59 LCD_iniz();
Dance 0:b3e41ec91adf 60 // start interval interrupt
Dance 0:b3e41ec91adf 61 f25k.attach_us( &interval_25k, FREQ / IPC );
Dance 0:b3e41ec91adf 62 // LCD test
Dance 0:b3e41ec91adf 63 LCD_cmd( 0x80 );
Dance 0:b3e41ec91adf 64 LCD_puts( "LCR Mete" );
Dance 0:b3e41ec91adf 65 LCD_cmd( 0xC0 );
Dance 0:b3e41ec91adf 66 LCD_puts( "r V0.0" );
Dance 0:b3e41ec91adf 67 // Main routine
Dance 0:b3e41ec91adf 68 for( ; ; ) {
Dance 0:b3e41ec91adf 69 // copy raw data to calc. buffer
Dance 0:b3e41ec91adf 70 for( i = 0; IPC > i; i ++ ) vcalc[i] = Vraw[i], icalc[i] = Iraw[i];
Dance 0:b3e41ec91adf 71 // calc. in-phase and quad-phase
Dance 0:b3e41ec91adf 72 vi = vq = ii = iq = 0.0;
Dance 0:b3e41ec91adf 73 for( i = 0; IPC > i; i ++ ) {
Dance 0:b3e41ec91adf 74 a = 2 * PI * (double)i / (double)IPC;
Dance 0:b3e41ec91adf 75 vi = vi + vcalc[i] * sin( a );
Dance 0:b3e41ec91adf 76 vq = vq + vcalc[i] * cos( a );
Dance 0:b3e41ec91adf 77 ii = ii - icalc[i] * sin( a );
Dance 0:b3e41ec91adf 78 iq = iq - icalc[i] * cos( a );
Dance 0:b3e41ec91adf 79 }
Dance 0:b3e41ec91adf 80 // gain calc.
Dance 0:b3e41ec91adf 81 a = ( R3 * ( R4 + R5 ) ) / ( R4 * ( R2 + R3 ) );
Dance 0:b3e41ec91adf 82 vi /= a; // voltage real
Dance 0:b3e41ec91adf 83 vq /= a; // voltage imaginary
Dance 0:b3e41ec91adf 84 ii /= R1; // current real
Dance 0:b3e41ec91adf 85 iq /= R1; // current immaginary
Dance 0:b3e41ec91adf 86 // divide : Z = v / i
Dance 0:b3e41ec91adf 87 if( 0.0 != ii || 0.0 != iq ) {
Dance 0:b3e41ec91adf 88 a = ii * ii + iq * iq;
Dance 0:b3e41ec91adf 89 r = ( ( vi * ii ) + ( vq * iq ) ) / a;
Dance 0:b3e41ec91adf 90 x = ( ( vq * ii ) - ( vi * iq ) ) / a;
Dance 0:b3e41ec91adf 91 }
Dance 0:b3e41ec91adf 92 else {
Dance 0:b3e41ec91adf 93 r = 999999.9, x = 999999.9; // hi-Z
Dance 0:b3e41ec91adf 94 }
Dance 0:b3e41ec91adf 95 // display R
Dance 0:b3e41ec91adf 96 if( 1000.0 > r ) sprintf( s, "R%4.1f ", r );
Dance 0:b3e41ec91adf 97 else if( 10000.0 > r ) sprintf( s, "R%2.3fK ", r / 1000.0 );
Dance 0:b3e41ec91adf 98 else if( 100000.0 > r ) sprintf( s, "R%3.2fK ", r / 1000.0 );
Dance 0:b3e41ec91adf 99 else sprintf( s, "R ----- " );
Dance 0:b3e41ec91adf 100 LCD_cmd( 0x80 );
Dance 0:b3e41ec91adf 101 LCD_puts( s );
Dance 0:b3e41ec91adf 102 // display X
Dance 0:b3e41ec91adf 103 if( 0 < x ) {
Dance 0:b3e41ec91adf 104 // inductance
Dance 0:b3e41ec91adf 105 x = x / ( 2.0 * PI * FREQ ); // H
Dance 0:b3e41ec91adf 106 if( 1.0 > x ) sprintf( s, "L%4.1fm ", x * 1000.0 );
Dance 0:b3e41ec91adf 107 else if( 10.0 > x ) sprintf( s, "L%2.3f ", x );
Dance 0:b3e41ec91adf 108 else if( 100.0 > x ) sprintf( s, "L%3.2f ", x );
Dance 0:b3e41ec91adf 109 else sprintf( s, "L ----- " );
Dance 0:b3e41ec91adf 110 }
Dance 0:b3e41ec91adf 111 else {
Dance 0:b3e41ec91adf 112 // capacitance
Dance 0:b3e41ec91adf 113 x = -1000000.0 / ( x * 2.0 * PI * FREQ ); // uF
Dance 0:b3e41ec91adf 114 if( 1.0 > x ) sprintf( s, "C%4.1fn ", x * 1000.0 );
Dance 0:b3e41ec91adf 115 else if( 10.0 > x ) sprintf( s, "C%2.3fu ", x );
Dance 0:b3e41ec91adf 116 else if( 100.0 > x ) sprintf( s, "C%3.2fu ", x );
Dance 0:b3e41ec91adf 117 else sprintf( s, "C ----- " );
Dance 0:b3e41ec91adf 118 }
Dance 0:b3e41ec91adf 119 LCD_cmd( 0xC0 );
Dance 0:b3e41ec91adf 120 LCD_puts( s );
Dance 0:b3e41ec91adf 121 }
Dance 0:b3e41ec91adf 122 }
Dance 0:b3e41ec91adf 123