- */\r
-void SweepLFrange()\r
-{\r
- BYTE *dest = (BYTE *)BigBuf;\r
- int i;\r
-\r
- // clear buffer\r
- memset(BigBuf,0,sizeof(BigBuf));\r
-\r
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
- for (i=255; i>19; i--) {\r
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, i);\r
- SpinDelay(20);\r
- dest[i] = (137500 * AvgAdc(4)) >> 18;\r
- }\r
-}\r
-\r
-void MeasureAntennaTuning(void)\r
-{\r
-// Impedances are Zc = 1/(j*omega*C), in ohms\r
-#define LF_TUNING_CAP_Z 1273 // 1 nF @ 125 kHz\r
-#define HF_TUNING_CAP_Z 235 // 50 pF @ 13.56 MHz\r
-\r
- int vLf125, vLf134, vHf; // in mV\r
-\r
- UsbCommand c;\r
-\r
- // Let the FPGA drive the low-frequency antenna around 125 kHz.\r
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz\r
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER | FPGA_LF_READER_USE_125_KHZ);\r
- SpinDelay(20);\r
- vLf125 = AvgAdc(4);\r
- // Vref = 3.3V, and a 10000:240 voltage divider on the input\r
- // can measure voltages up to 137500 mV\r
- vLf125 = (137500 * vLf125) >> 10;\r
-\r
- // Let the FPGA drive the low-frequency antenna around 134 kHz.\r
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz\r
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER | FPGA_LF_READER_USE_134_KHZ);\r
- SpinDelay(20);\r
- vLf134 = AvgAdc(4);\r
- // Vref = 3.3V, and a 10000:240 voltage divider on the input\r
- // can measure voltages up to 137500 mV\r
- vLf134 = (137500 * vLf134) >> 10;\r
-\r
- // Let the FPGA drive the high-frequency antenna around 13.56 MHz.\r
- FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);\r
- SpinDelay(20);\r
- vHf = AvgAdc(5);\r
- // Vref = 3300mV, and an 10:1 voltage divider on the input\r
- // can measure voltages up to 33000 mV\r
- vHf = (33000 * vHf) >> 10;\r
-\r
- c.cmd = CMD_MEASURED_ANTENNA_TUNING;\r
- c.ext1 = (vLf125 << 0) | (vLf134 << 16);\r
- c.ext2 = vHf;\r
- c.ext3 = (LF_TUNING_CAP_Z << 0) | (HF_TUNING_CAP_Z << 16);\r
- UsbSendPacket((BYTE *)&c, sizeof(c));\r
-}\r
-\r
-void SimulateTagLowFrequency(int period)\r
-{\r
- int i;\r
- BYTE *tab = (BYTE *)BigBuf;\r
-\r
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);\r
-\r
- PIO_ENABLE = (1 << GPIO_SSC_DOUT) | (1 << GPIO_SSC_CLK);\r
-\r
- PIO_OUTPUT_ENABLE = (1 << GPIO_SSC_DOUT);\r
- PIO_OUTPUT_DISABLE = (1 << GPIO_SSC_CLK);\r
-\r
-#define SHORT_COIL() LOW(GPIO_SSC_DOUT)\r
-#define OPEN_COIL() HIGH(GPIO_SSC_DOUT)\r
-\r
- i = 0;\r
- for(;;) {\r
- while(!(PIO_PIN_DATA_STATUS & (1<<GPIO_SSC_CLK))) {\r
- if(BUTTON_PRESS()) {\r
- return;\r
- }\r
- WDT_HIT();\r
- }\r
-\r
- LED_D_ON();\r
- if(tab[i]) {\r
- OPEN_COIL();\r
- } else {\r
- SHORT_COIL();\r
- }\r
- LED_D_OFF();\r
-\r
- while(PIO_PIN_DATA_STATUS & (1<<GPIO_SSC_CLK)) {\r
- if(BUTTON_PRESS()) {\r
- return;\r
- }\r
- WDT_HIT();\r
- }\r
-\r
- i++;\r
- if(i == period) i = 0;\r
- }\r
-}\r
-\r
-// compose fc/8 fc/10 waveform\r
-static void fc(int c, int *n) {\r
- BYTE *dest = (BYTE *)BigBuf;\r
- int idx;\r
-\r
- // for when we want an fc8 pattern every 4 logical bits\r
- if(c==0) {\r
- dest[((*n)++)]=1;\r
- dest[((*n)++)]=1;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- }\r
- // an fc/8 encoded bit is a bit pattern of 11000000 x6 = 48 samples\r
- if(c==8) {\r
- for (idx=0; idx<6; idx++) {\r
- dest[((*n)++)]=1;\r
- dest[((*n)++)]=1;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- }\r
- }\r
-\r
- // an fc/10 encoded bit is a bit pattern of 1110000000 x5 = 50 samples\r
- if(c==10) {\r
- for (idx=0; idx<5; idx++) {\r
- dest[((*n)++)]=1;\r
- dest[((*n)++)]=1;\r
- dest[((*n)++)]=1;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- dest[((*n)++)]=0;\r
- }\r
- }\r
-}\r
-\r
-// prepare a waveform pattern in the buffer based on the ID given then\r
-// simulate a HID tag until the button is pressed\r
-static void CmdHIDsimTAG(int hi, int lo)\r
-{\r
- int n=0, i=0;\r
- /*\r
- HID tag bitstream format\r
- The tag contains a 44bit unique code. This is sent out MSB first in sets of 4 bits\r
- A 1 bit is represented as 6 fc8 and 5 fc10 patterns\r
- A 0 bit is represented as 5 fc10 and 6 fc8 patterns\r
- A fc8 is inserted before every 4 bits\r
- A special start of frame pattern is used consisting a0b0 where a and b are neither 0\r
- nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)\r
- */\r
-\r
- if (hi>0xFFF) {\r
- DbpString("Tags can only have 44 bits.");\r
- return;\r
- }\r
- fc(0,&n);\r
- // special start of frame marker containing invalid bit sequences\r
- fc(8, &n); fc(8, &n); // invalid\r
- fc(8, &n); fc(10, &n); // logical 0\r
- fc(10, &n); fc(10, &n); // invalid\r
- fc(8, &n); fc(10, &n); // logical 0\r
-\r
- WDT_HIT();\r
- // manchester encode bits 43 to 32\r
- for (i=11; i>=0; i--) {\r
- if ((i%4)==3) fc(0,&n);\r
- if ((hi>>i)&1) {\r
- fc(10, &n); fc(8, &n); // low-high transition\r
- } else {\r
- fc(8, &n); fc(10, &n); // high-low transition\r
- }\r
- }\r
-\r
- WDT_HIT();\r
- // manchester encode bits 31 to 0\r
- for (i=31; i>=0; i--) {\r
- if ((i%4)==3) fc(0,&n);\r
- if ((lo>>i)&1) {\r
- fc(10, &n); fc(8, &n); // low-high transition\r
- } else {\r
- fc(8, &n); fc(10, &n); // high-low transition\r
- }\r
- }\r
-\r
- LED_A_ON();\r
- SimulateTagLowFrequency(n);\r
- LED_A_OFF();\r
-}\r
-\r
-// loop to capture raw HID waveform then FSK demodulate the TAG ID from it\r
-static void CmdHIDdemodFSK(void)\r
-{\r
- BYTE *dest = (BYTE *)BigBuf;\r
- int m=0, n=0, i=0, idx=0, found=0, lastval=0;\r
- DWORD hi=0, lo=0;\r
-\r
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz\r
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER | FPGA_LF_READER_USE_125_KHZ);\r
-\r
- // Connect the A/D to the peak-detected low-frequency path.\r
- SetAdcMuxFor(GPIO_MUXSEL_LOPKD);\r
-\r
- // Give it a bit of time for the resonant antenna to settle.\r
- SpinDelay(50);\r
-\r
- // Now set up the SSC to get the ADC samples that are now streaming at us.\r
- FpgaSetupSsc();\r
-\r
- for(;;) {\r
- WDT_HIT();\r
- LED_A_ON();\r
- if(BUTTON_PRESS()) {\r
- LED_A_OFF();\r
- return;\r
- }\r
-\r
- i = 0;\r
- m = sizeof(BigBuf);\r
- memset(dest,128,m);\r
- for(;;) {\r
- if(SSC_STATUS & (SSC_STATUS_TX_READY)) {\r
- SSC_TRANSMIT_HOLDING = 0x43;\r
- LED_D_ON();\r
- }\r
- if(SSC_STATUS & (SSC_STATUS_RX_READY)) {\r
- dest[i] = (BYTE)SSC_RECEIVE_HOLDING;\r
- // we don't care about actual value, only if it's more or less than a\r
- // threshold essentially we capture zero crossings for later analysis\r
- if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;\r
- i++;\r
- LED_D_OFF();\r
- if(i >= m) {\r
- break;\r
- }\r
- }\r
- }\r
-\r
- // FSK demodulator\r
-\r
- // sync to first lo-hi transition\r
- for( idx=1; idx<m; idx++) {\r
- if (dest[idx-1]<dest[idx])\r
- lastval=idx;\r
- break;\r
- }\r
- WDT_HIT();\r
-\r
- // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)\r
- // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere\r
- // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10\r
- for( i=0; idx<m; idx++) {\r
- if (dest[idx-1]<dest[idx]) {\r
- dest[i]=idx-lastval;\r
- if (dest[i] <= 8) {\r
- dest[i]=1;\r
- } else {\r
- dest[i]=0;\r
- }\r
-\r
- lastval=idx;\r
- i++;\r
- }\r
- }\r
- m=i;\r
- WDT_HIT();\r
-\r
- // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns\r
- lastval=dest[0];\r
- idx=0;\r
- i=0;\r
- n=0;\r
- for( idx=0; idx<m; idx++) {\r
- if (dest[idx]==lastval) {\r
- n++;\r
- } else {\r
- // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,\r
- // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets\r
- // swallowed up by rounding\r
- // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding\r
- // special start of frame markers use invalid manchester states (no transitions) by using sequences\r
- // like 111000\r
- if (dest[idx-1]) {\r
- n=(n+1)/6; // fc/8 in sets of 6\r
- } else {\r
- n=(n+1)/5; // fc/10 in sets of 5\r
- }\r
- switch (n) { // stuff appropriate bits in buffer\r
- case 0:\r
- case 1: // one bit\r
- dest[i++]=dest[idx-1];\r
- break;\r
- case 2: // two bits\r
- dest[i++]=dest[idx-1];\r
- dest[i++]=dest[idx-1];\r
- break;\r
- case 3: // 3 bit start of frame markers\r
- dest[i++]=dest[idx-1];\r
- dest[i++]=dest[idx-1];\r
- dest[i++]=dest[idx-1];\r
- break;\r
- // When a logic 0 is immediately followed by the start of the next transmisson\r
- // (special pattern) a pattern of 4 bit duration lengths is created.\r
- case 4:\r
- dest[i++]=dest[idx-1];\r
- dest[i++]=dest[idx-1];\r
- dest[i++]=dest[idx-1];\r
- dest[i++]=dest[idx-1];\r
- break;\r
- default: // this shouldn't happen, don't stuff any bits\r
- break;\r
- }\r
- n=0;\r
- lastval=dest[idx];\r
- }\r
- }\r
- m=i;\r
- WDT_HIT();\r
-\r
- // final loop, go over previously decoded manchester data and decode into usable tag ID\r
- // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0\r
- for( idx=0; idx<m-6; idx++) {\r
- // search for a start of frame marker\r
- if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )\r
- {\r
- found=1;\r
- idx+=6;\r
- if (found && (hi|lo)) {\r
- DbpString("TAG ID");\r
- DbpIntegers(hi, lo, (lo>>1)&0xffff);\r
- hi=0;\r
- lo=0;\r
- found=0;\r
- }\r
- }\r
- if (found) {\r
- if (dest[idx] && (!dest[idx+1]) ) {\r
- hi=(hi<<1)|(lo>>31);\r
- lo=(lo<<1)|0;\r
- } else if ( (!dest[idx]) && dest[idx+1]) {\r
- hi=(hi<<1)|(lo>>31);\r
- lo=(lo<<1)|1;\r
- } else {\r
- found=0;\r
- hi=0;\r
- lo=0;\r
- }\r
- idx++;\r
- }\r
- if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )\r
- {\r
- found=1;\r
- idx+=6;\r
- if (found && (hi|lo)) {\r
- DbpString("TAG ID");\r
- DbpIntegers(hi, lo, (lo>>1)&0xffff);\r
- hi=0;\r
- lo=0;\r
- found=0;\r
- }\r
- }\r
- }\r
- WDT_HIT();\r
- }\r
-}\r
-\r
-void SimulateTagHfListen(void)\r
-{\r
- BYTE *dest = (BYTE *)BigBuf;\r
- int n = sizeof(BigBuf);\r
- BYTE v = 0;\r
- int i;\r
- int p = 0;\r
-\r
- // We're using this mode just so that I can test it out; the simulated\r
- // tag mode would work just as well and be simpler.\r
- FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | FPGA_HF_READER_RX_XCORR_SNOOP);\r
-\r
- // We need to listen to the high-frequency, peak-detected path.\r
- SetAdcMuxFor(GPIO_MUXSEL_HIPKD);\r
-\r
- FpgaSetupSsc();\r
-\r
- i = 0;\r
- for(;;) {\r
- if(SSC_STATUS & (SSC_STATUS_TX_READY)) {\r
- SSC_TRANSMIT_HOLDING = 0xff;\r
- }\r
- if(SSC_STATUS & (SSC_STATUS_RX_READY)) {\r
- BYTE r = (BYTE)SSC_RECEIVE_HOLDING;\r
-\r
- v <<= 1;\r
- if(r & 1) {\r
- v |= 1;\r
- }\r
- p++;\r
-\r
- if(p >= 8) {\r
- dest[i] = v;\r
- v = 0;\r
- p = 0;\r
- i++;\r
-\r
- if(i >= n) {\r
- break;\r
- }\r
- }\r
- }\r
- }\r
- DbpString("simulate tag (now type bitsamples)");\r
-}\r
-\r
-void UsbPacketReceived(BYTE *packet, int len)\r
-{\r
- UsbCommand *c = (UsbCommand *)packet;\r
-\r
- switch(c->cmd) {\r
- case CMD_ACQUIRE_RAW_ADC_SAMPLES_125K:\r
- AcquireRawAdcSamples125k(c->ext1);\r
- break;\r
-\r
- case CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_15693:\r
- AcquireRawAdcSamplesIso15693();\r
- break;\r
-\r
- case CMD_READER_ISO_15693:\r
- ReaderIso15693(c->ext1);\r
- break;\r
-\r
- case CMD_SIMTAG_ISO_15693:\r
- SimTagIso15693(c->ext1);\r
- break;\r
-\r
- case CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_14443:\r
- AcquireRawAdcSamplesIso14443(c->ext1);\r
- break;\r
-\r
- case CMD_READER_ISO_14443a:\r
- ReaderIso14443a(c->ext1);\r
- break;\r
-\r
- case CMD_SNOOP_ISO_14443:\r
- SnoopIso14443();\r
- break;\r
-\r
- case CMD_SNOOP_ISO_14443a:\r
- SnoopIso14443a();\r
- break;\r
-\r
- case CMD_SIMULATE_TAG_HF_LISTEN:\r
- SimulateTagHfListen();\r
- break;\r
-\r
- case CMD_SIMULATE_TAG_ISO_14443:\r
- SimulateIso14443Tag();\r
- break;\r
-\r
- case CMD_SIMULATE_TAG_ISO_14443a:\r
- SimulateIso14443aTag(c->ext1, c->ext2); // ## Simulate iso14443a tag - pass tag type & UID\r
- break;\r
-\r
- case CMD_MEASURE_ANTENNA_TUNING:\r
- MeasureAntennaTuning();\r
- break;\r
-\r
- case CMD_HID_DEMOD_FSK:\r
- CmdHIDdemodFSK(); // Demodulate HID tag\r
- break;\r
-\r
- case CMD_HID_SIM_TAG:\r
- CmdHIDsimTAG(c->ext1, c->ext2); // Simulate HID tag by ID\r
- break;\r
-\r
- case CMD_FPGA_MAJOR_MODE_OFF: // ## FPGA Control\r
- LED_C_ON();\r
- FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);\r
- SpinDelay(200);\r
- LED_C_OFF();\r
- break;\r
-\r
- case CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K:\r
- case CMD_DOWNLOAD_RAW_BITS_TI_TYPE: {\r
- UsbCommand n;\r
- if(c->cmd == CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K) {\r
- n.cmd = CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K;\r
- } else {\r
- n.cmd = CMD_DOWNLOADED_RAW_BITS_TI_TYPE;\r
- }\r
- n.ext1 = c->ext1;\r
- memcpy(n.d.asDwords, BigBuf+c->ext1, 12*sizeof(DWORD));\r
- UsbSendPacket((BYTE *)&n, sizeof(n));\r
- break;\r
- }\r
- case CMD_DOWNLOADED_SIM_SAMPLES_125K: {\r
- BYTE *b = (BYTE *)BigBuf;\r
- memcpy(b+c->ext1, c->d.asBytes, 48);\r
- break;\r
- }\r
- case CMD_SIMULATE_TAG_125K:\r
- LED_A_ON();\r
- SimulateTagLowFrequency(c->ext1);\r
- LED_A_OFF();\r
- break;\r
-\r
- case CMD_LCD_RESET:\r
- LCDReset();\r
- break;\r
-\r
- case CMD_SWEEP_LF:\r
- SweepLFrange();\r
- break;\r
-\r
- case CMD_SET_LF_DIVISOR:\r
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, c->ext1);\r
- break;\r
-\r
- case CMD_LCD:\r
- LCDSend(c->ext1);\r
- break;\r
-\r
- case CMD_SETUP_WRITE:\r
- case CMD_FINISH_WRITE:\r
- USB_D_PLUS_PULLUP_OFF();\r
- SpinDelay(1000);\r
- SpinDelay(1000);\r
- RSTC_CONTROL = RST_CONTROL_KEY | RST_CONTROL_PROCESSOR_RESET;\r
- for(;;) {\r
- // We're going to reset, and the bootrom will take control.\r
- }\r
- break;\r
-\r
- default:\r
- DbpString("unknown command");\r
- break;\r
- }\r
-}\r
-\r
-void AppMain(void)\r
-{\r
- memset(BigBuf,0,sizeof(BigBuf));\r
- SpinDelay(100);\r
-\r
- LED_D_OFF();\r
- LED_C_OFF();\r
- LED_B_OFF();\r
- LED_A_OFF();\r
-\r
- UsbStart();\r
-\r
- // The FPGA gets its clock from us from PCK0 output, so set that up.\r
- PIO_PERIPHERAL_B_SEL = (1 << GPIO_PCK0);\r
- PIO_DISABLE = (1 << GPIO_PCK0);\r
- PMC_SYS_CLK_ENABLE = PMC_SYS_CLK_PROGRAMMABLE_CLK_0;\r
- // PCK0 is PLL clock / 4 = 96Mhz / 4 = 24Mhz\r
- PMC_PROGRAMMABLE_CLK_0 = PMC_CLK_SELECTION_PLL_CLOCK |\r
- PMC_CLK_PRESCALE_DIV_4;\r
- PIO_OUTPUT_ENABLE = (1 << GPIO_PCK0);\r
-\r
- // Reset SPI\r
- SPI_CONTROL = SPI_CONTROL_RESET;\r
- // Reset SSC\r
- SSC_CONTROL = SSC_CONTROL_RESET;\r
-\r
- // Load the FPGA image, which we have stored in our flash.\r
- FpgaDownloadAndGo();\r
-\r
- LCDInit();\r
-\r
- // test text on different colored backgrounds\r
- LCDString(" The quick brown fox ", &FONT6x8,1,1+8*0,WHITE ,BLACK );\r
- LCDString(" jumped over the ", &FONT6x8,1,1+8*1,BLACK ,WHITE );\r
- LCDString(" lazy dog. ", &FONT6x8,1,1+8*2,YELLOW ,RED );\r
- LCDString(" AaBbCcDdEeFfGgHhIiJj ", &FONT6x8,1,1+8*3,RED ,GREEN );\r
- LCDString(" KkLlMmNnOoPpQqRrSsTt ", &FONT6x8,1,1+8*4,MAGENTA,BLUE );\r
- LCDString("UuVvWwXxYyZz0123456789", &FONT6x8,1,1+8*5,BLUE ,YELLOW);\r
- LCDString("`-=[]_;',./~!@#$%^&*()", &FONT6x8,1,1+8*6,BLACK ,CYAN );\r
- LCDString(" _+{}|:\\\"<>? ",&FONT6x8,1,1+8*7,BLUE ,MAGENTA);\r
-\r
- // color bands\r
- LCDFill(0, 1+8* 8, 132, 8, BLACK);\r
- LCDFill(0, 1+8* 9, 132, 8, WHITE);\r
- LCDFill(0, 1+8*10, 132, 8, RED);\r
- LCDFill(0, 1+8*11, 132, 8, GREEN);\r
- LCDFill(0, 1+8*12, 132, 8, BLUE);\r
- LCDFill(0, 1+8*13, 132, 8, YELLOW);\r
- LCDFill(0, 1+8*14, 132, 8, CYAN);\r
- LCDFill(0, 1+8*15, 132, 8, MAGENTA);\r
-\r
- for(;;) {\r
- UsbPoll(FALSE);\r
- WDT_HIT();\r
- }\r
-}\r
-\r
-void SpinDelay(int ms)\r
-{\r
- int ticks = (48000*ms) >> 10;\r
-\r
- // Borrow a PWM unit for my real-time clock\r
- PWM_ENABLE = PWM_CHANNEL(0);\r
- // 48 MHz / 1024 gives 46.875 kHz\r
- PWM_CH_MODE(0) = PWM_CH_MODE_PRESCALER(10);\r
- PWM_CH_DUTY_CYCLE(0) = 0;\r
- PWM_CH_PERIOD(0) = 0xffff;\r
-\r
- WORD start = (WORD)PWM_CH_COUNTER(0);\r
-\r
- for(;;) {\r
- WORD now = (WORD)PWM_CH_COUNTER(0);\r
- if(now == (WORD)(start + ticks)) {\r
- return;\r
- }\r
- WDT_HIT();\r
- }\r
-}\r
+ */
+void SweepLFrange()
+{
+ BYTE *dest = (BYTE *)BigBuf;
+ char dummy[12];
+ int i, peak= 0, ptr= 0;
+ double freq;
+
+ // clear buffer
+ memset(BigBuf,0,sizeof(BigBuf));
+
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ for (i=255; i>19; i--) {
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, i);
+ SpinDelay(20);
+ dest[i] = (137500 * AvgAdc(ADC_CHAN_LF)) >> 18;
+ if(dest[i] > peak) {
+ peak= dest[i];
+ ptr= i;
+ }
+ }
+ dummy[11]= '\0';
+ dummy[10]= 'z';
+ dummy[9]= 'H';
+ dummy[8]= 'k';
+ dummy[7]= ' ';
+ freq= 12000000/(ptr + 1);
+ for(i= 6; i > 3 ; --i) {
+ dummy[i]= '0' + ((int) freq) % 10;
+ freq /= 10;
+ }
+ dummy[3]= '.';
+ for(i= 2; i >= 0 ; --i) {
+ dummy[i]= '0' + ((int) freq) % 10;
+ freq /= 10;
+ }
+ DbpString("Antenna resonates at:");
+ DbpString(dummy);
+}
+
+void MeasureAntennaTuning(void)
+{
+// Impedances are Zc = 1/(j*omega*C), in ohms
+#define LF_TUNING_CAP_Z 1273 // 1 nF @ 125 kHz
+#define HF_TUNING_CAP_Z 235 // 50 pF @ 13.56 MHz
+
+ int vLf125, vLf134, vHf; // in mV
+
+ UsbCommand c;
+
+ // Let the FPGA drive the low-frequency antenna around 125 kHz.
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER | FPGA_LF_READER_USE_125_KHZ);
+ SpinDelay(20);
+ vLf125 = AvgAdc(ADC_CHAN_LF);
+ // Vref = 3.3V, and a 10000:240 voltage divider on the input
+ // can measure voltages up to 137500 mV
+ vLf125 = (137500 * vLf125) >> 10;
+
+ // Let the FPGA drive the low-frequency antenna around 134 kHz.
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER | FPGA_LF_READER_USE_134_KHZ);
+ SpinDelay(20);
+ vLf134 = AvgAdc(ADC_CHAN_LF);
+ // Vref = 3.3V, and a 10000:240 voltage divider on the input
+ // can measure voltages up to 137500 mV
+ vLf134 = (137500 * vLf134) >> 10;
+
+ // Let the FPGA drive the high-frequency antenna around 13.56 MHz.
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);
+ SpinDelay(20);
+ vHf = AvgAdc(ADC_CHAN_HF);
+ // Vref = 3300mV, and an 10:1 voltage divider on the input
+ // can measure voltages up to 33000 mV
+ vHf = (33000 * vHf) >> 10;
+
+ c.cmd = CMD_MEASURED_ANTENNA_TUNING;
+ c.ext1 = (vLf125 << 0) | (vLf134 << 16);
+ c.ext2 = vHf;
+ c.ext3 = (LF_TUNING_CAP_Z << 0) | (HF_TUNING_CAP_Z << 16);
+ UsbSendPacket((BYTE *)&c, sizeof(c));
+}
+
+void SimulateTagLowFrequency(int period)
+{
+ int i;
+ BYTE *tab = (BYTE *)BigBuf;
+
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);
+
+ PIO_ENABLE = (1 << GPIO_SSC_DOUT) | (1 << GPIO_SSC_CLK);
+
+ PIO_OUTPUT_ENABLE = (1 << GPIO_SSC_DOUT);
+ PIO_OUTPUT_DISABLE = (1 << GPIO_SSC_CLK);
+
+#define SHORT_COIL() LOW(GPIO_SSC_DOUT)
+#define OPEN_COIL() HIGH(GPIO_SSC_DOUT)
+
+ i = 0;
+ for(;;) {
+ while(!(PIO_PIN_DATA_STATUS & (1<<GPIO_SSC_CLK))) {
+ if(BUTTON_PRESS()) {
+ DbpString("Stopped");
+ return;
+ }
+ WDT_HIT();
+ }
+
+ LED_D_ON();
+ if(tab[i]) {
+ OPEN_COIL();
+ } else {
+ SHORT_COIL();
+ }
+ LED_D_OFF();
+
+ while(PIO_PIN_DATA_STATUS & (1<<GPIO_SSC_CLK)) {
+ if(BUTTON_PRESS()) {
+ DbpString("Stopped");
+ return;
+ }
+ WDT_HIT();
+ }
+
+ i++;
+ if(i == period) i = 0;
+ }
+}
+
+// compose fc/8 fc/10 waveform
+static void fc(int c, int *n) {
+ BYTE *dest = (BYTE *)BigBuf;
+ int idx;
+
+ // for when we want an fc8 pattern every 4 logical bits
+ if(c==0) {
+ dest[((*n)++)]=1;
+ dest[((*n)++)]=1;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ }
+ // an fc/8 encoded bit is a bit pattern of 11000000 x6 = 48 samples
+ if(c==8) {
+ for (idx=0; idx<6; idx++) {
+ dest[((*n)++)]=1;
+ dest[((*n)++)]=1;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ }
+ }
+
+ // an fc/10 encoded bit is a bit pattern of 1110000000 x5 = 50 samples
+ if(c==10) {
+ for (idx=0; idx<5; idx++) {
+ dest[((*n)++)]=1;
+ dest[((*n)++)]=1;
+ dest[((*n)++)]=1;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ dest[((*n)++)]=0;
+ }
+ }
+}
+
+// prepare a waveform pattern in the buffer based on the ID given then
+// simulate a HID tag until the button is pressed
+static void CmdHIDsimTAG(int hi, int lo)
+{
+ int n=0, i=0;
+ /*
+ HID tag bitstream format
+ The tag contains a 44bit unique code. This is sent out MSB first in sets of 4 bits
+ A 1 bit is represented as 6 fc8 and 5 fc10 patterns
+ A 0 bit is represented as 5 fc10 and 6 fc8 patterns
+ A fc8 is inserted before every 4 bits
+ A special start of frame pattern is used consisting a0b0 where a and b are neither 0
+ nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)
+ */
+
+ if (hi>0xFFF) {
+ DbpString("Tags can only have 44 bits.");
+ return;
+ }
+ fc(0,&n);
+ // special start of frame marker containing invalid bit sequences
+ fc(8, &n); fc(8, &n); // invalid
+ fc(8, &n); fc(10, &n); // logical 0
+ fc(10, &n); fc(10, &n); // invalid
+ fc(8, &n); fc(10, &n); // logical 0
+
+ WDT_HIT();
+ // manchester encode bits 43 to 32
+ for (i=11; i>=0; i--) {
+ if ((i%4)==3) fc(0,&n);
+ if ((hi>>i)&1) {
+ fc(10, &n); fc(8, &n); // low-high transition
+ } else {
+ fc(8, &n); fc(10, &n); // high-low transition
+ }
+ }
+
+ WDT_HIT();
+ // manchester encode bits 31 to 0
+ for (i=31; i>=0; i--) {
+ if ((i%4)==3) fc(0,&n);
+ if ((lo>>i)&1) {
+ fc(10, &n); fc(8, &n); // low-high transition
+ } else {
+ fc(8, &n); fc(10, &n); // high-low transition
+ }
+ }
+
+ LED_A_ON();
+ SimulateTagLowFrequency(n);
+ LED_A_OFF();
+}
+
+// loop to capture raw HID waveform then FSK demodulate the TAG ID from it
+static void CmdHIDdemodFSK(void)
+{
+ BYTE *dest = (BYTE *)BigBuf;
+ int m=0, n=0, i=0, idx=0, found=0, lastval=0;
+ DWORD hi=0, lo=0;
+
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER | FPGA_LF_READER_USE_125_KHZ);
+
+ // Connect the A/D to the peak-detected low-frequency path.
+ SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+
+ // Give it a bit of time for the resonant antenna to settle.
+ SpinDelay(50);
+
+ // Now set up the SSC to get the ADC samples that are now streaming at us.
+ FpgaSetupSsc();
+
+ for(;;) {
+ WDT_HIT();
+ LED_A_ON();
+ if(BUTTON_PRESS()) {
+ DbpString("Stopped");
+ LED_A_OFF();
+ return;
+ }
+
+ i = 0;
+ m = sizeof(BigBuf);
+ memset(dest,128,m);
+ for(;;) {
+ if(SSC_STATUS & (SSC_STATUS_TX_READY)) {
+ SSC_TRANSMIT_HOLDING = 0x43;
+ LED_D_ON();
+ }
+ if(SSC_STATUS & (SSC_STATUS_RX_READY)) {
+ dest[i] = (BYTE)SSC_RECEIVE_HOLDING;
+ // we don't care about actual value, only if it's more or less than a
+ // threshold essentially we capture zero crossings for later analysis
+ if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
+ i++;
+ LED_D_OFF();
+ if(i >= m) {
+ break;
+ }
+ }
+ }
+
+ // FSK demodulator
+
+ // sync to first lo-hi transition
+ for( idx=1; idx<m; idx++) {
+ if (dest[idx-1]<dest[idx])
+ lastval=idx;
+ break;
+ }
+ WDT_HIT();
+
+ // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
+ // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
+ // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
+ for( i=0; idx<m; idx++) {
+ if (dest[idx-1]<dest[idx]) {
+ dest[i]=idx-lastval;
+ if (dest[i] <= 8) {
+ dest[i]=1;
+ } else {
+ dest[i]=0;
+ }
+
+ lastval=idx;
+ i++;
+ }
+ }
+ m=i;
+ WDT_HIT();
+
+ // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
+ lastval=dest[0];
+ idx=0;
+ i=0;
+ n=0;
+ for( idx=0; idx<m; idx++) {
+ if (dest[idx]==lastval) {
+ n++;
+ } else {
+ // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
+ // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
+ // swallowed up by rounding
+ // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
+ // special start of frame markers use invalid manchester states (no transitions) by using sequences
+ // like 111000
+ if (dest[idx-1]) {
+ n=(n+1)/6; // fc/8 in sets of 6
+ } else {
+ n=(n+1)/5; // fc/10 in sets of 5
+ }
+ switch (n) { // stuff appropriate bits in buffer
+ case 0:
+ case 1: // one bit
+ dest[i++]=dest[idx-1];
+ break;
+ case 2: // two bits
+ dest[i++]=dest[idx-1];
+ dest[i++]=dest[idx-1];
+ break;
+ case 3: // 3 bit start of frame markers
+ dest[i++]=dest[idx-1];
+ dest[i++]=dest[idx-1];
+ dest[i++]=dest[idx-1];
+ break;
+ // When a logic 0 is immediately followed by the start of the next transmisson
+ // (special pattern) a pattern of 4 bit duration lengths is created.
+ case 4:
+ dest[i++]=dest[idx-1];
+ dest[i++]=dest[idx-1];
+ dest[i++]=dest[idx-1];
+ dest[i++]=dest[idx-1];
+ break;
+ default: // this shouldn't happen, don't stuff any bits
+ break;
+ }
+ n=0;
+ lastval=dest[idx];
+ }
+ }
+ m=i;
+ WDT_HIT();
+
+ // final loop, go over previously decoded manchester data and decode into usable tag ID
+ // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
+ for( idx=0; idx<m-6; idx++) {
+ // search for a start of frame marker
+ if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
+ {
+ found=1;
+ idx+=6;
+ if (found && (hi|lo)) {
+ DbpString("TAG ID");
+ DbpIntegers(hi, lo, (lo>>1)&0xffff);
+ hi=0;
+ lo=0;
+ found=0;
+ }
+ }
+ if (found) {
+ if (dest[idx] && (!dest[idx+1]) ) {
+ hi=(hi<<1)|(lo>>31);
+ lo=(lo<<1)|0;
+ } else if ( (!dest[idx]) && dest[idx+1]) {
+ hi=(hi<<1)|(lo>>31);
+ lo=(lo<<1)|1;
+ } else {
+ found=0;
+ hi=0;
+ lo=0;
+ }
+ idx++;
+ }
+ if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
+ {
+ found=1;
+ idx+=6;
+ if (found && (hi|lo)) {
+ DbpString("TAG ID");
+ DbpIntegers(hi, lo, (lo>>1)&0xffff);
+ hi=0;
+ lo=0;
+ found=0;
+ }
+ }
+ }
+ WDT_HIT();
+ }
+}
+
+void SimulateTagHfListen(void)
+{
+ BYTE *dest = (BYTE *)BigBuf;
+ int n = sizeof(BigBuf);
+ BYTE v = 0;
+ int i;
+ int p = 0;
+
+ // We're using this mode just so that I can test it out; the simulated
+ // tag mode would work just as well and be simpler.
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | FPGA_HF_READER_RX_XCORR_SNOOP);
+
+ // We need to listen to the high-frequency, peak-detected path.
+ SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+
+ FpgaSetupSsc();
+
+ i = 0;
+ for(;;) {
+ if(SSC_STATUS & (SSC_STATUS_TX_READY)) {
+ SSC_TRANSMIT_HOLDING = 0xff;
+ }
+ if(SSC_STATUS & (SSC_STATUS_RX_READY)) {
+ BYTE r = (BYTE)SSC_RECEIVE_HOLDING;
+
+ v <<= 1;
+ if(r & 1) {
+ v |= 1;
+ }
+ p++;
+
+ if(p >= 8) {
+ dest[i] = v;
+ v = 0;
+ p = 0;
+ i++;
+
+ if(i >= n) {
+ break;
+ }
+ }
+ }
+ }
+ DbpString("simulate tag (now type bitsamples)");
+}
+
+void UsbPacketReceived(BYTE *packet, int len)
+{
+ UsbCommand *c = (UsbCommand *)packet;
+
+ switch(c->cmd) {
+ case CMD_ACQUIRE_RAW_ADC_SAMPLES_125K:
+ AcquireRawAdcSamples125k(c->ext1);
+ break;
+
+ case CMD_MOD_THEN_ACQUIRE_RAW_ADC_SAMPLES_125K:
+ ModThenAcquireRawAdcSamples125k(c->ext1,c->ext2,c->ext3,c->d.asBytes);
+ break;
+
+ case CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_15693:
+ AcquireRawAdcSamplesIso15693();
+ break;
+
+ case CMD_BUFF_CLEAR:
+ BufferClear();
+ break;
+
+ case CMD_READER_ISO_15693:
+ ReaderIso15693(c->ext1);
+ break;
+
+ case CMD_SIMTAG_ISO_15693:
+ SimTagIso15693(c->ext1);
+ break;
+
+ case CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_14443:
+ AcquireRawAdcSamplesIso14443(c->ext1);
+ break;
+
+ case CMD_READ_SRI512_TAG:
+ ReadSRI512Iso14443(c->ext1);
+ break;
+
+ case CMD_READER_ISO_14443a:
+ ReaderIso14443a(c->ext1);
+ break;
+
+ case CMD_SNOOP_ISO_14443:
+ SnoopIso14443();
+ break;
+
+ case CMD_SNOOP_ISO_14443a:
+ SnoopIso14443a();
+ break;
+
+ case CMD_SIMULATE_TAG_HF_LISTEN:
+ SimulateTagHfListen();
+ break;
+
+ case CMD_SIMULATE_TAG_ISO_14443:
+ SimulateIso14443Tag();
+ break;
+
+ case CMD_SIMULATE_TAG_ISO_14443a:
+ SimulateIso14443aTag(c->ext1, c->ext2); // ## Simulate iso14443a tag - pass tag type & UID
+ break;
+
+ case CMD_MEASURE_ANTENNA_TUNING:
+ MeasureAntennaTuning();
+ break;
+
+ case CMD_LISTEN_READER_FIELD:
+ ListenReaderField(c->ext1);
+ break;
+
+ case CMD_HID_DEMOD_FSK:
+ CmdHIDdemodFSK(); // Demodulate HID tag
+ break;
+
+ case CMD_HID_SIM_TAG:
+ CmdHIDsimTAG(c->ext1, c->ext2); // Simulate HID tag by ID
+ break;
+
+ case CMD_FPGA_MAJOR_MODE_OFF: // ## FPGA Control
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+ SpinDelay(200);
+ LED_D_OFF(); // LED D indicates field ON or OFF
+ break;
+
+ case CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K:
+ case CMD_DOWNLOAD_RAW_BITS_TI_TYPE: {
+ UsbCommand n;
+ if(c->cmd == CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K) {
+ n.cmd = CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K;
+ } else {
+ n.cmd = CMD_DOWNLOADED_RAW_BITS_TI_TYPE;
+ }
+ n.ext1 = c->ext1;
+ memcpy(n.d.asDwords, BigBuf+c->ext1, 12*sizeof(DWORD));
+ UsbSendPacket((BYTE *)&n, sizeof(n));
+ break;
+ }
+ case CMD_DOWNLOADED_SIM_SAMPLES_125K: {
+ BYTE *b = (BYTE *)BigBuf;
+ memcpy(b+c->ext1, c->d.asBytes, 48);
+ break;
+ }
+ case CMD_SIMULATE_TAG_125K:
+ LED_A_ON();
+ SimulateTagLowFrequency(c->ext1);
+ LED_A_OFF();
+ break;
+#ifdef WITH_LCD
+ case CMD_LCD_RESET:
+ LCDReset();
+ break;
+#endif
+ case CMD_SWEEP_LF:
+ SweepLFrange();
+ break;
+
+ case CMD_SET_LF_DIVISOR:
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, c->ext1);
+ break;
+#ifdef WITH_LCD
+ case CMD_LCD:
+ LCDSend(c->ext1);
+ break;
+#endif
+ case CMD_SETUP_WRITE:
+ case CMD_FINISH_WRITE:
+ case CMD_HARDWARE_RESET:
+ USB_D_PLUS_PULLUP_OFF();
+ SpinDelay(1000);
+ SpinDelay(1000);
+ RSTC_CONTROL = RST_CONTROL_KEY | RST_CONTROL_PROCESSOR_RESET;
+ for(;;) {
+ // We're going to reset, and the bootrom will take control.
+ }
+ break;
+
+
+ default:
+ DbpString("unknown command");
+ break;
+ }
+}
+
+void AppMain(void)
+{
+ memset(BigBuf,0,sizeof(BigBuf));
+ SpinDelay(100);
+
+ LED_D_OFF();
+ LED_C_OFF();
+ LED_B_OFF();
+ LED_A_OFF();
+
+ UsbStart();
+
+ // The FPGA gets its clock from us from PCK0 output, so set that up.
+ PIO_PERIPHERAL_B_SEL = (1 << GPIO_PCK0);
+ PIO_DISABLE = (1 << GPIO_PCK0);
+ PMC_SYS_CLK_ENABLE = PMC_SYS_CLK_PROGRAMMABLE_CLK_0;
+ // PCK0 is PLL clock / 4 = 96Mhz / 4 = 24Mhz
+ PMC_PROGRAMMABLE_CLK_0 = PMC_CLK_SELECTION_PLL_CLOCK |
+ PMC_CLK_PRESCALE_DIV_4;
+ PIO_OUTPUT_ENABLE = (1 << GPIO_PCK0);
+
+ // Reset SPI
+ SPI_CONTROL = SPI_CONTROL_RESET;
+ // Reset SSC
+ SSC_CONTROL = SSC_CONTROL_RESET;
+
+ // Load the FPGA image, which we have stored in our flash.
+ FpgaDownloadAndGo();
+
+#ifdef WITH_LCD
+
+ LCDInit();
+
+ // test text on different colored backgrounds
+ LCDString(" The quick brown fox ", &FONT6x8,1,1+8*0,WHITE ,BLACK );
+ LCDString(" jumped over the ", &FONT6x8,1,1+8*1,BLACK ,WHITE );
+ LCDString(" lazy dog. ", &FONT6x8,1,1+8*2,YELLOW ,RED );
+ LCDString(" AaBbCcDdEeFfGgHhIiJj ", &FONT6x8,1,1+8*3,RED ,GREEN );
+ LCDString(" KkLlMmNnOoPpQqRrSsTt ", &FONT6x8,1,1+8*4,MAGENTA,BLUE );
+ LCDString("UuVvWwXxYyZz0123456789", &FONT6x8,1,1+8*5,BLUE ,YELLOW);
+ LCDString("`-=[]_;',./~!@#$%^&*()", &FONT6x8,1,1+8*6,BLACK ,CYAN );
+ LCDString(" _+{}|:\\\"<>? ",&FONT6x8,1,1+8*7,BLUE ,MAGENTA);
+
+ // color bands
+ LCDFill(0, 1+8* 8, 132, 8, BLACK);
+ LCDFill(0, 1+8* 9, 132, 8, WHITE);
+ LCDFill(0, 1+8*10, 132, 8, RED);
+ LCDFill(0, 1+8*11, 132, 8, GREEN);
+ LCDFill(0, 1+8*12, 132, 8, BLUE);
+ LCDFill(0, 1+8*13, 132, 8, YELLOW);
+ LCDFill(0, 1+8*14, 132, 8, CYAN);
+ LCDFill(0, 1+8*15, 132, 8, MAGENTA);
+
+#endif
+
+ for(;;) {
+ UsbPoll(FALSE);
+ WDT_HIT();
+ }
+}
+
+void SpinDelayUs(int us)
+{
+ int ticks = (48*us) >> 10;
+
+ // Borrow a PWM unit for my real-time clock
+ PWM_ENABLE = PWM_CHANNEL(0);
+ // 48 MHz / 1024 gives 46.875 kHz
+ PWM_CH_MODE(0) = PWM_CH_MODE_PRESCALER(10);
+ PWM_CH_DUTY_CYCLE(0) = 0;
+ PWM_CH_PERIOD(0) = 0xffff;
+
+ WORD start = (WORD)PWM_CH_COUNTER(0);
+
+ for(;;) {
+ WORD now = (WORD)PWM_CH_COUNTER(0);
+ if(now == (WORD)(start + ticks)) {
+ return;
+ }
+ WDT_HIT();
+ }
+}
+
+void SpinDelay(int ms)
+{
+ int ticks = (48000*ms) >> 10;
+
+ // Borrow a PWM unit for my real-time clock
+ PWM_ENABLE = PWM_CHANNEL(0);
+ // 48 MHz / 1024 gives 46.875 kHz
+ PWM_CH_MODE(0) = PWM_CH_MODE_PRESCALER(10);
+ PWM_CH_DUTY_CYCLE(0) = 0;
+ PWM_CH_PERIOD(0) = 0xffff;
+
+ WORD start = (WORD)PWM_CH_COUNTER(0);
+
+ for(;;) {
+ WORD now = (WORD)PWM_CH_COUNTER(0);
+ if(now == (WORD)(start + ticks)) {
+ return;
+ }
+ WDT_HIT();
+ }
+}
+
+// listen for external reader
+void ListenReaderField(int limit)
+{
+ int lf_av, lf_av_new, lf_baseline= 0, lf_count= 0;
+ int hf_av, hf_av_new, hf_baseline= 0, hf_count= 0;
+
+#define LF_ONLY 1
+#define HF_ONLY 2
+
+ LED_A_OFF();
+ LED_B_OFF();
+ LED_C_OFF();
+ LED_D_OFF();
+
+ lf_av= ReadAdc(ADC_CHAN_LF);
+
+ if(limit != HF_ONLY)
+ {
+ DbpString("LF 125/134 Baseline:");
+ DbpIntegers(lf_av,0,0);
+ lf_baseline= lf_av;
+ }
+
+ hf_av= ReadAdc(ADC_CHAN_HF);
+
+
+ if (limit != LF_ONLY)
+ {
+ DbpString("HF 13.56 Baseline:");
+ DbpIntegers(hf_av,0,0);
+ hf_baseline= hf_av;
+ }
+
+ for(;;)
+ {
+ if(BUTTON_PRESS())
+ {
+ DbpString("Stopped");
+ LED_B_OFF();
+ LED_D_OFF();
+ return;
+ }
+ WDT_HIT();
+
+
+ if (limit != HF_ONLY)
+ {
+ if (abs(lf_av - lf_baseline) > 10)
+ LED_D_ON();
+ else
+ LED_D_OFF();
+ ++lf_count;
+ lf_av_new= ReadAdc(ADC_CHAN_LF);
+ // see if there's a significant change
+ if(abs(lf_av - lf_av_new) > 10)
+ {
+ DbpString("LF 125/134 Field Change:");
+ DbpIntegers(lf_av,lf_av_new,lf_count);
+ lf_av= lf_av_new;
+ lf_count= 0;
+ }
+ }
+
+ if (limit != LF_ONLY)
+ {
+ if (abs(hf_av - hf_baseline) > 10)
+ LED_B_ON();
+ else
+ LED_B_OFF();
+ ++hf_count;
+ hf_av_new= ReadAdc(ADC_CHAN_HF);
+ // see if there's a significant change
+ if(abs(hf_av - hf_av_new) > 10)
+ {
+ DbpString("HF 13.56 Field Change:");
+ DbpIntegers(hf_av,hf_av_new,hf_count);
+ hf_av= hf_av_new;
+ hf_count= 0;
+ }
+ }
+ }
+}