X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/77aecdd2865d4b2dcb7d231c125920820081a7b9..854fdf15e074c6d282f08ff0bea555810f52c664:/armsrc/appmain.c diff --git a/armsrc/appmain.c b/armsrc/appmain.c index e292483b..679a533a 100644 --- a/armsrc/appmain.c +++ b/armsrc/appmain.c @@ -31,7 +31,7 @@ #endif // Craig Young - 14a stand-alone code -#ifdef WITH_ISO14443a_StandAlone +#ifdef WITH_ISO14443a #include "iso14443a.h" #endif @@ -135,35 +135,28 @@ void Dbhexdump(int len, uint8_t *d, bool bAsci) { // return that. //----------------------------------------------------------------------------- static int ReadAdc(int ch) -{ - uint32_t d; - - AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST; - AT91C_BASE_ADC->ADC_MR = - ADC_MODE_PRESCALE(63 /* was 32 */) | // ADC_CLK = MCK / ((63+1) * 2) = 48MHz / 128 = 375kHz - ADC_MODE_STARTUP_TIME(1 /* was 16 */) | // Startup Time = (1+1) * 8 / ADC_CLK = 16 / 375kHz = 42,7us Note: must be > 20us - ADC_MODE_SAMPLE_HOLD_TIME(15 /* was 8 */); // Sample & Hold Time SHTIM = 15 / ADC_CLK = 15 / 375kHz = 40us - +{ // Note: ADC_MODE_PRESCALE and ADC_MODE_SAMPLE_HOLD_TIME are set to the maximum allowed value. - // Both AMPL_LO and AMPL_HI are very high impedance (10MOhm) outputs, the input capacitance of the ADC is 12pF (typical). This results in a time constant - // of RC = 10MOhm * 12pF = 120us. Even after the maximum configurable sample&hold time of 40us the input capacitor will not be fully charged. + // AMPL_HI is are high impedance (10MOhm || 1MOhm) output, the input capacitance of the ADC is 12pF (typical). This results in a time constant + // of RC = (0.91MOhm) * 12pF = 10.9us. Even after the maximum configurable sample&hold time of 40us the input capacitor will not be fully charged. // // The maths are: // If there is a voltage v_in at the input, the voltage v_cap at the capacitor (this is what we are measuring) will be // - // v_cap = v_in * (1 - exp(-RC/SHTIM)) = v_in * (1 - exp(-3)) = v_in * 0,95 (i.e. an error of 5%) - // - // Note: with the "historic" values in the comments above, the error was 34% !!! - - AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ch); + // v_cap = v_in * (1 - exp(-SHTIM/RC)) = v_in * (1 - exp(-40us/10.9us)) = v_in * 0,97 (i.e. an error of 3%) - AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; + AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST; + AT91C_BASE_ADC->ADC_MR = + ADC_MODE_PRESCALE(63) | // ADC_CLK = MCK / ((63+1) * 2) = 48MHz / 128 = 375kHz + ADC_MODE_STARTUP_TIME(1) | // Startup Time = (1+1) * 8 / ADC_CLK = 16 / 375kHz = 42,7us Note: must be > 20us + ADC_MODE_SAMPLE_HOLD_TIME(15); // Sample & Hold Time SHTIM = 15 / ADC_CLK = 15 / 375kHz = 40us - while(!(AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ch))) - ; - d = AT91C_BASE_ADC->ADC_CDR[ch]; + AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ch); + AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; - return d; + while(!(AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ch))) {}; + + return AT91C_BASE_ADC->ADC_CDR[ch]; } int AvgAdc(int ch) // was static - merlok @@ -193,6 +186,8 @@ void MeasureAntennaTuningLfOnly(int *vLf125, int *vLf134, int *peakf, int *peakv FpgaDownloadAndGo(FPGA_BITSTREAM_LF); FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD); + SpinDelay(50); + for (i=255; i>=19; i--) { WDT_HIT(); FpgaSendCommand(FPGA_CMD_SET_DIVISOR, i); @@ -201,7 +196,7 @@ void MeasureAntennaTuningLfOnly(int *vLf125, int *vLf134, int *peakf, int *peakv if (i==95) *vLf125 = adcval; // voltage at 125Khz if (i==89) *vLf134 = adcval; // voltage at 134Khz - LF_Results[i] = adcval>>8; // scale int to fit in byte for graphing purposes + LF_Results[i] = adcval >> 9; // scale int to fit in byte for graphing purposes if(LF_Results[i] > peak) { *peakv = adcval; peak = LF_Results[i]; @@ -249,7 +244,7 @@ void MeasureAntennaTuning(int mode) } } - cmd_send(CMD_MEASURED_ANTENNA_TUNING, vLf125 | (vLf134<<16), vHf, peakf | (peakv<<16), LF_Results, 256); + cmd_send(CMD_MEASURED_ANTENNA_TUNING, vLf125>>1 | (vLf134>>1<<16), vHf, peakf | (peakv>>1<<16), LF_Results, 256); FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LED_B_OFF(); return;