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I try to get an board identification by reading the voltage of an resistor network with the internal ADC of the controller.
At some boards I get a wrong value for the voltage but I can measure the good voltage with my multimeter.
So I think there is an software problem.
I use this function :
// ---------------------------------------------------------------------------------------------------
// init of ADC's
// ---------------------------------------------------------------------------------------------------
void adcInit(void) {
// Setup ADCTRL1 x000 0000 0011 xxxx b --> 0x0030
// Bit 15 = 0 --> reserved
AdcRegs.ADCTRL1.all = 0x0030; // Bit 14 = 0 --> no reset adc
// Bit 13 - 12 = 00 --> no stop in emulation mode
// Bit 11 - 8 = 0000 --> acquisition window size
// = (zzzz + 1) x ADCCLK
// Bit 7 = 0 --> adcclk : 1
// Bit 6 = 0 --> disable continuous run
// --> d.h. start/stop Mode
// Bit 5 = 1 --> enable Sequencer override feature
// Bit 4 = 1 --> Cascaded mode
// Bit 3 - 0 = 0000 --> reserved
// Setup ADCTRL2 010x 00x0 0100 0000 b --> 0x4040
AdcRegs.ADCTRL2.all = 0x4040; // Bit 15 = 0 --> no SOCB for cascaded seq
// Bit 14 = 1 --> reset sequencer-1
// Bit 13 = 0 --> no SOC for sequencer-1
// Bit 12 = 0 --> reserved
// Bit 11 = 0 --> no INT_ENA_SEQ1
// Bit 10 = 0 --> INT_MOD_SEQ1
// Bit 9 = 0 --> reserved
// Bit 8 = 0 --> no SOCA for sequencer-1
// Bit 7 = 0 --> no EXT_SOC for sequencer-1
// Bit 6 = 1 --> reset sequencer-2
// Bit 5 = 0 --> no SOC for sequencer-2
// Bit 4 = 0 --> reserved
// Bit 3 = 0 --> no INT_ENA_SEQ2
// Bit 2 = 0 --> INT_MOD_SEQ2
// Bit 1 = 0 --> reserved
// Bit 0 = 0 --> no SOCB for sequencer-2
// stop conversion
// Setup ADCTRL3 xxxx xxxx 1110 0110 b --> 0x00E6 --> 12.5 MHz
// Setup ADCTRL3 xxxx xxxx 1110 1000 b --> 0x00E8 --> 6.75 MHz
// Setup ADCTRL3 xxxx xxxx 1110 1010 b --> 0x00EA --> 3.125 MHz
AdcRegs.ADCTRL3.all = 0x00E6; // Power up bandgap/reference/ADC circuits
// Bit 7-6 --> bandgap on
// Bit 5 --> analog on
// Bit 4-1 --> clk div = 6 --> 12.5 MHz
// high-speed peripheri-clk ist bei diesem
// Beispiel auf 75 MHz eingestellt
// Bit 0 --> sequential sampling mode
// Setup ADCMAXCONV xxxx xxxx x000 1111 b --> 0x000F
AdcRegs.ADCMAXCONV.all = 0x000F; // convert and store in 16 results registers
// Setup ADCASEQSR wird nicht ben"otigt, liefert nur den Status
// AdcRegs.ADCASEQSR.all = 0x0000;
// Setup ADCST wird nicht ben"otigt, liefert nur den Status
// bzw dient dem L"oschen von Interrupt-flags
// AdcRegs.ADCST.all = 0x0000;
// Setup ADCREFSEL
AdcRegs.ADCREFSEL.bit.REF_SEL = 1; // externe Vref mit 2.048 V
// Setup ADCREFSEL 01yy yyyy yyyy yyyy b --> 0x4000
// AdcRegs.ADCREFSEL.all = 0x4000 ; // externe Vref mit 2.048 V
// zerst"ort ggf. Calibrierwerte
// Setup ADCOFFTRIM xxxx xxxx yyyy yyyy b --> 0x????
// AdcRegs.ADCOFFTRIM.all = 0x0000 ; // wird durch adc_cal eingestellt
// AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x0; // Beispiel f"ur das einstellen der einzelnen Kan"ale
AdcRegs.ADCCHSELSEQ1.all = 0x0000; // Initialize all ADC channel selects to A0
AdcRegs.ADCCHSELSEQ2.all = 0x0000;
AdcRegs.ADCCHSELSEQ3.all = 0x0000;
AdcRegs.ADCCHSELSEQ4.all = 0x0000;
}
Read function :
// ---------------------------------------------------------------------------------------------------
// mehrfaches lesen eines einzelnen ADC Kanals mit Mittelwertbildung
// ---------------------------------------------------------------------------------------------------
uint16_t adcReadMultiChannel(uint16_t kanal, uint16_t mittelwert) {
WRITE_TRACE("adcReadMultiChannel", TRACE_MSG, 0, 0, 0);
uint16_t adc_ergebnis = 0;
uint16_t adc_schleife = 0;
kanal &= 0x000F; // stellenbegrenzung
mittelwert &= 0x000F; // begrenzt den wert
adc_ergebnis = kanal; // 3. Kanal
adc_ergebnis <<= 4;
adc_ergebnis += kanal; // 2. Kanal
adc_ergebnis <<= 4;
adc_ergebnis += kanal; // 1. Kanal
adc_ergebnis <<= 4;
adc_ergebnis += kanal; // 0. Kanal
AdcRegs.ADCCHSELSEQ1.all = adc_ergebnis; // Initialize all ADC channel selects to kanal
AdcRegs.ADCCHSELSEQ2.all = adc_ergebnis;
AdcRegs.ADCCHSELSEQ3.all = adc_ergebnis;
AdcRegs.ADCCHSELSEQ4.all = adc_ergebnis;
AdcRegs.ADCMAXCONV.all = mittelwert; // anzahl der messungen zur mittelwertbildung
// 0x0 --> 1 Wandlung
// 0xF --> 16 Wandlungen
AdcRegs.ADCTRL2.bit.SOC_SEQ1 = 1; // start of new conversion
while (AdcRegs.ADCST.bit.INT_SEQ1 == 0) {;} // end of conversion
adc_schleife = mittelwert;
adc_schleife += 1; // 0xF --> 16 Wandlungen
adc_ergebnis = 0; // r"ucksetzen des Messwertes
while (adc_schleife) {
adc_ergebnis += (*((volatile int16_t far *) (0x00000AFF + adc_schleife)));
adc_schleife--;
}
mittelwert += 1; // 0xF --> 16 Wandlungen
adc_ergebnis /= mittelwert;
adc_ergebnis &= 0x0FFF; // vorsichtsmassnahme eigentlich unn"otig
return adc_ergebnis;
}
Is there any error at this fubctions ?
with best regards
Peter Schneider
Electronic Engineering
Stanley Engineered Fastening
Tucker GmbH
Max-Eyth-Str. 1, 35394 Giessen, Germany
office: +49.(0)641.405.428 | fax: +49.(0)641.405.724
Amtsgericht Gießen, HRB 1775
Geschäftsführer: Mike A. Tyll, Manfred Müller, Martin Kreimer
