Diff: main.cpp
- Revision:
- 1:0d88cfafe20e
- Parent:
- 0:197cfa57c3c7
- Child:
- 2:ddc96642fcdb
--- a/main.cpp Wed Mar 22 17:05:11 2017 +0000
+++ b/main.cpp Wed Mar 22 21:59:37 2017 +0000
@@ -1,12 +1,12 @@
-/* PULSED DISCHARGE BATTERY CAPACITY MEASUREMENT
+/* BATTERY ESR MEASUREMENT
Note: The design intent was to calibrate each board rather than designing
and assembling precision analog circuits for each shield-board.
- Use compile directive switch "CAL" in this firmware to perform test to
+ Use compiler directive switch in this firmware to perform routine to
obtain calibration coeficients for each board. Place these obtained cal
- coefficients in the CALIBRATION CONSTANTS section
+ coefficients in the CALIBRATION CONSTANTS section and then recompile for test mode
- See ENG-1492 for more details and results
+ See ENG-1493 for more details and results
**** Be sure to set the approriate BOARDNUMBER before compiling ***********
@@ -14,199 +14,97 @@
#include "mbed.h"
-#include "SDFileSystem.h"
Serial pc(SERIAL_TX, SERIAL_RX);
-AnalogOut DAC_Out(PA_4); // Connected to Gate of MOSFET
-AnalogIn VRin(PA_0); // for Current Measurement
+DigitalOut MOSFET(PA_4); // Connected to Gate of MOSFET
AnalogIn VBin(PA_1); // To measure battery Voltage
DigitalOut LED(D4); // Activity indicator
-SDFileSystem sd(D11, D12, D13, D10, "sd"); // the pinout on the mbed Cool Components workshop board
+#define WIRE_LEAD_RES (0.23F)
// BOARD SPECIFIC CALIBRATION CONSTANTS
#define BOARDNUMBER 1
#if BOARDNUMBER == 1
-#define DAC100MA 35470
-#define I_SCALE 0.332386F
-#define V_SCALE 3.314950F
+#define V_SCALE 3.735935F
#elif BOARDNUMBER == 2
- #define DAC100MA 35950
+#define V_SCALE 3.3F
#elif BOARDNUMBER == 3
- #define DAC100MA 35950
+#define V_SCALE 3.3F
#else
- #define DAC100MA 35950
+#define V_SCALE 3.3F
#endif
// Parameters
-#define PULSEWIDTH 0.099f
-#define INTERVAL 0.599f
-#define SLEWRATE 100 //10 is good for active testing, 100 for debugging
-#define VBATTERY_MIN (3.00f)
-#define TERMINATION_CURRENT (0.067f)
-#define HYST (0.0001f) // temp comp hysteresis
-#define GAIN 10000 // temp comp gain
+#define PULSEWIDTH 1.0f // seconds
char serial_inchar,waiting;
void OnSerial(void) // serial port interrupt used in calibration mode
{
serial_inchar = pc.getc();
waiting = 0;
- printf("%c:%d",serial_inchar,serial_inchar);
}
int main() {
- float I,V,I_Target;
- uint16_t DAC_Value = DAC100MA;
- uint32_t count;
-
- DAC_Out.write_u16(0);
+ float OpenVoltage,LoadVoltage;
pc.baud(115200);
- printf("Pulsed Battery Discharger\n\r");
+ printf("Battery ESR Tester\n\r");
pc.attach(&OnSerial);
+
+ MOSFET = 0;
LED = 0;
- wait(1);
- waiting = 1;
-
-// FILE *fp = fopen("/sd/sdtest.txt", "w");
-// if(fp == NULL) {
-// error("Could not open file for write\n");
-// }
#if 1 // 0 = Calibration Mode, 1= Discharge test mode
- FILE *fp = fopen("/sd/BatteryLog.txt", "w");
- if(fp == NULL) {
- error("Could not open file for write\n");
- }
-
- fprintf(fp, "I,V,count\n");
- printf("\n\rBattery Discharge Mode\n\r");
- I_Target = 0.100;
- do {
-
+ printf("Test Mode\n\r");
+ while(1) {
+ waiting = 1;
+ while(waiting){
+ wait(0.1);
+ }
+ OpenVoltage = VBin.read()* V_SCALE;
+ LED = 1;
+ MOSFET = 1;
+ wait(PULSEWIDTH);
+ LoadVoltage = VBin.read()* V_SCALE;
LED = 0;
- DAC_Out.write_u16(0);
- wait(INTERVAL);
- LED = 1;
- DAC_Out.write_u16(DAC_Value);
- wait(PULSEWIDTH);
- I = VRin.read()* I_SCALE;
- V = VBin.read()* V_SCALE;
+ MOSFET = 0;
- fprintf(fp,"%1.3f,%1.2f,%d\n",I,V,++count);
- //printf("%1.3f,%1.2f,%d\n\r",I,V,count);
-
-
- // temperature compensation
- if (I < (I_Target - HYST)) {
- DAC_Value += (I_Target - I)*GAIN;
- }
- else if ( I > (I_Target + HYST)) {
- DAC_Value -= (I - I_Target)*GAIN;
- }
-
-
- // If battery Voltage goes below BATTERY_MIN then reduce current
- if (V < VBATTERY_MIN) {
- if (I_Target > ( TERMINATION_CURRENT - (2.0*HYST))) {
- I_Target -= 0.001;
- }
- }
-
- } while (I > TERMINATION_CURRENT && waiting);
-
- fclose(fp);
- DAC_Out.write_u16(0);
- printf("Done!\n\r");
- LED = 0;
+ printf("Open Voltage = %1.3f, Loaded Voltage = %1.3f, ESR = %1.3f\n\r",
+ OpenVoltage,LoadVoltage,(OpenVoltage-LoadVoltage)/(LoadVoltage/3.0f)-WIRE_LEAD_RES);
+ }
#else
+
//Perform Board Calibration
printf("\n\rCalibration Mode\n\r");
waiting = 1;
while (pc.readable()) { // flush buffer
serial_inchar = pc.getc();
}
- printf("Set Vin to 3.20V then [press any key]\n\r");
+ printf("Set Vin to 3.600V then [press any key]\n\r");
while(waiting == 1){
wait(0.05);
}
- printf("OK\n\r");
+ printf("Reading...\n\r");
wait(0.5);
- V = VBin.read();
+ OpenVoltage = VBin.read();
- printf("Setting Current to 100mA\n\r");
- printf("Use +, -, *, / to adjust, q to end\n\r");
-
- DAC_Value = 35550;
- DAC_Out.write_u16(DAC_Value);
+ printf("Cut/paste this calibration into the calibration section...\n\r\n\r");
+ printf("#define V_SCALE %fF\n\r",3.6/OpenVoltage);
- waiting = 1;
- do {
- while(waiting){wait(0.01);}
- printf("=%c",serial_inchar);
- switch (serial_inchar) {
- case '+':
- DAC_Value += 10;
- break;
- case '-':
- DAC_Value -= 10;
- break;
- case '*':
- DAC_Value += 100;
- break;
- case '/':
- DAC_Value -= 100;
- break;
- }
- DAC_Out.write_u16(DAC_Value);
- waiting = 1;
- } while (serial_inchar != 'q');
- I = VRin.read();
- DAC_Out.write_u16(0);
- printf("\n\rVIN VALUE: %f\n\rDACVALUE: %d\n\r,I in:%f\n\r",V,DAC_Value,I);
- printf("Cut/paste this calibration into the calibration section...\n\r\n\r");
- printf("#define DAC100MA %d\n\r",DAC_Value);
- printf("#define I_SCALE %fF\n\r",0.1/I);
- printf("#define V_SCALE %fF\n\r",3.2/V);
- printf("\n\r\n\r");
-
-
- // Validation test
- float test_I_SCALE = 0.1/I;
- float test_V_SCALE = 3.2/V;
- while(serial_inchar == 'q') {
- DAC_Out.write_u16(DAC_Value);
- wait(INTERVAL+PULSEWIDTH);
- I = VRin.read()* test_I_SCALE;
- V = VBin.read()* test_V_SCALE;
-
- printf("%1.4f,%1.2f,%d\n\r",I,V,DAC_Value);
-
- // temperature compensation
- if (I < (0.100 - HYST)) {
- DAC_Value += (0.1 - I)*GAIN;
- }
- else if ( I > (0.100 + HYST)) {
- DAC_Value -= (I - 0.1)*GAIN;;
- }
-
- }
- DAC_Out.write_u16(0);
#endif
PNI
