chg: 'lf cmdread' @marshmellow42 improvements from https://github.com/Proxmark/proxmark3/pull/570

chg:  and some adaptations..

armsrc/lfops.c

@@ -4,7 +4,7 @@
 // the license.
 //-----------------------------------------------------------------------------
 // Miscellaneous routines for low frequency tag operations.
-// Tags supported here so far are Texas Instruments (TI), HID
+// Tags supported here so far are Texas Instruments (TI), HID, EM4x05, EM410x
 // Also routines for raw mode reading/simulating of LF waveform
 //-----------------------------------------------------------------------------
 
@@ -55,47 +55,101 @@
 /**
  * Function to do a modulation and then get samples.
  * @param delay_off
- * @param periods  0xFFFF0000 is period_0,  0x0000FFFF is period_1
+ * @param period_0
- * @param useHighFreg
+ * @param period_1
- * @param command
+ * @param command (in binary char array)
  */
-void ModThenAcquireRawAdcSamples125k(uint32_t delay_off, uint32_t periods, uint32_t useHighFreq, uint8_t *command) {
+void ModThenAcquireRawAdcSamples125k(uint32_t delay_off, uint32_t period_0, uint32_t period_1, uint8_t *command) {
-	uint16_t period_0 =  periods >> 16;
+
-	uint16_t period_1 =  periods & 0xFFFF;
+	// start timer
-	
+	StartTicks();
-	// 95 == 125 KHz  88 == 134.8 KHz
+
-	int divisor_used = (useHighFreq) ? 88 : 95;
+	// use lf config settings
-	sample_config sc = { 0,0,1, divisor_used, 0};
+	sample_config *sc = getSamplingConfig();
-	setSamplingConfig(&sc);
 
 	//clear read buffer
 	BigBuf_Clear_keep_EM();
 
-	LFSetupFPGAForADC(sc.divisor, 1);
+	LFSetupFPGAForADC(sc->divisor, 1);
 	
 	// Trigger T55x7 in mode.
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	WaitUS(START_GAP);
 	
+	// And a little more time for the tag to fully power up
+	WaitMS(2000);
+	
+	// if delay_off = 0 then just bitbang 1 = antenna on 0 = off for respective periods.
+	bool bitbang = delay_off == 0;
 	// now modulate the reader field
-	while (*command != '\0' && *command != ' ') {
+	if (bitbang) {
-		LED_D_ON();
+		// HACK it appears the loop and if statements take up about 7us so adjust waits accordingly...
-		if (*(command++) == '0')
+		uint8_t hack_cnt = 7;
-			TurnReadLFOn(period_0);
+		if (period_0 < hack_cnt || period_1 < hack_cnt) {
-		else
+			DbpString("[!] Warning periods cannot be less than 7us in bit bang mode");
-			TurnReadLFOn(period_1);
+			FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+			LED_D_OFF();
+			return;
+		}
 
-		LED_D_OFF();
+		// hack2 needed---  it appears to take about 8-16us to turn the antenna back on 
-		FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+		// leading to ~ 1 to 2 125khz samples extra in every off period 
-		WaitUS(delay_off);		
+		// so we should test for last 0 before next 1 and reduce period_0 by this extra amount...
+		// but is this time different for every antenna or other hw builds???  more testing needed
+
+		// prime cmd_len to save time comparing strings while modulating
+		int cmd_len = 0;
+		while(command[cmd_len] != '\0' && command[cmd_len] != ' ')
+			cmd_len++;
+
+		int counter = 0;
+		bool off = false;
+		for (counter = 0; counter < cmd_len; counter++) {
+			// if cmd = 0 then turn field off
+			if (command[counter] == '0') {
+				// if field already off leave alone (affects timing otherwise)
+				if (off == false) {
+					FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+					LED_D_OFF();
+					off = true;
+				}
+				// note we appear to take about 7us to switch over (or run the if statements/loop...)
+				WaitUS(period_0 - hack_cnt);
+			// else if cmd = 1 then turn field on
+			} else {
+				// if field already on leave alone (affects timing otherwise)
+				if (off) {
+					FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+					LED_D_ON();
+					off = false;
+				}
+				// note we appear to take about 7us to switch over (or run the if statements/loop...)
+				WaitUS(period_1 - hack_cnt);
+			}
+		}
+	} else { // old mode of cmd read using delay as off period
+		while(*command != '\0' && *command != ' ') {
+			LED_D_ON();
+			if (*(command++) == '0')
+				TurnReadLFOn(period_0);
+			else
+				TurnReadLFOn(period_1);
+
+			LED_D_OFF();
+			FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+			WaitUS(delay_off);
+		}
+
+		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, sc->divisor);
 	}
-	
+
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 
 	// now do the read
 	DoAcquisition_config(false, 0);
-	
+
+	// Turn off antenna	
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	// tell client we are done	
 	cmd_send(CMD_ACK,0,0,0,0,0);    
 }
 

client/cmdlf.c

@@ -14,19 +14,18 @@ bool g_lf_threshold_set = false;
 static int CmdHelp(const char *Cmd);
 
 int usage_lf_cmdread(void) {
-	PrintAndLog("Usage: lf cmdread d <delay period> z <zero period> o <one period> c <cmdbytes> [H]");
+	PrintAndLog("Usage: lf cmdread d <delay period> z <zero period> o <one period> c <cmdbytes>");
 	PrintAndLog("Options:");
 	PrintAndLog("       h             This help");
-	PrintAndLog("       L             Low frequency (125 KHz)");
+	PrintAndLog("       d <delay>     delay OFF period, (0 for bitbang mode) (decimal)");
-	PrintAndLog("       H             High frequency (134 KHz)");
-	PrintAndLog("       d <delay>     delay OFF period, (decimal)");
 	PrintAndLog("       z <zero>      time period ZERO, (decimal)");
 	PrintAndLog("       o <one>       time period ONE, (decimal)");
 	PrintAndLog("       c <cmd>       Command bytes  (in ones and zeros)");
+	PrintAndLog("");
 	PrintAndLog("       ************* All periods in microseconds (ms)");
+	PrintAndLog("       ************* Use lf config to configure options.");	
 	PrintAndLog("Examples:");
 	PrintAndLog("      lf cmdread d 80 z 100 o 200 c 11000");
-	PrintAndLog("      lf cmdread d 80 z 100 o 100 c 11000 H");
 	return 0;
 }
 int usage_lf_read(void){
@@ -144,23 +143,15 @@ int usage_lf_find(void){
 /* send a LF command before reading */
 int CmdLFCommandRead(const char *Cmd) {
 
-	bool errors = false;
-	bool useHighFreq = false;
-	uint16_t one = 0, zero = 0;
-  	uint8_t cmdp = 0;
 	UsbCommand c = {CMD_MOD_THEN_ACQUIRE_RAW_ADC_SAMPLES_125K, {0,0,0}};
-	
+	bool errors = false;
+
+  	uint8_t cmdp = 0;
 	while(param_getchar(Cmd, cmdp) != 0x00 && !errors) {
 		switch(param_getchar(Cmd, cmdp)) {
 		case 'h':
-			return usage_lf_cmdread();
 		case 'H':
-			useHighFreq = true;
+			return usage_lf_cmdread();
-			cmdp++;
-			break;
-		case 'L':
-			cmdp++;
-			break;
 		case 'c':
 			param_getstr(Cmd, cmdp+1, (char *)&c.d.asBytes, sizeof(c.d.asBytes));
 			cmdp += 2;
@@ -170,16 +161,16 @@ int CmdLFCommandRead(const char *Cmd) {
 			cmdp += 2;
 			break;
 		case 'z':
-			zero = param_get32ex(Cmd, cmdp+1, 0, 10) & 0xFFFF;
+			c.arg[1] = param_get32ex(Cmd, cmdp+1, 0, 10) & 0xFFFF;
 			cmdp += 2;
 			break;
 		case 'o':
-			one = param_get32ex(Cmd, cmdp+1, 0, 10) & 0xFFFF;
+			c.arg[2] = param_get32ex(Cmd, cmdp+1, 0, 10) & 0xFFFF;
 			cmdp += 2;
 			break;
 		default:
 			PrintAndLog("Unknown parameter '%c'", param_getchar(Cmd, cmdp));
-			errors = 1;
+			errors = true;
 			break;
 		}
 	}
@@ -187,14 +178,11 @@ int CmdLFCommandRead(const char *Cmd) {
 	//Validations
 	if (errors || cmdp == 0)  return usage_lf_cmdread();
 	
-	// zero and one lengths
-	c.arg[1] = (uint32_t)(zero << 16 | one);
-	
-	// add frequency 125 or 134
-	c.arg[2] = useHighFreq;
-
 	clearCommandBuffer();
 	SendCommand(&c);
+	
+	WaitForResponse(CMD_ACK, NULL);
+	getSamples(0, true);
 	return 0;
 }
 

client/cmdmain.c

@@ -165,7 +165,7 @@ bool WaitForResponseTimeoutW(uint32_t cmd, UsbCommand* response, size_t ms_timeo
 		
 		if (msclock() - start_time > 3000 && show_warning) {
 			PrintAndLog("Waiting for a response from the proxmark...");
-			PrintAndLog("Don't forget to cancel its operation first by pressing on the button");
+			PrintAndLog("You can cancel this operation by pressing the pm3 button");
 			show_warning = false;
 		}
 	}