diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index c6a65d50..7bf8f5af 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -1994,7 +1994,7 @@ int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data, uint8_t *res) {
 			*res = data_bytes[0];
 
 		// crc check
-		if (len >=3 && !CheckCrc14443(CRC_14443_A, data_bytes, len)) {
+		if (len >= 3 && !CheckCrc14443(CRC_14443_A, data_bytes, len)) {
 			return -1;
 		}
 		
diff --git a/client/cmdhf14a.c b/client/cmdhf14a.c
index 8947d798..15b3f0e8 100644
--- a/client/cmdhf14a.c
+++ b/client/cmdhf14a.c
@@ -747,11 +747,80 @@ int ExchangeRAW14a(uint8_t *datain, int datainlen, bool activateField, bool leav
 	return 0;
 }
 
+int CmdExchangeAPDU(uint8_t *datain, int datainlen, bool activateField, uint8_t *dataout, int maxdataoutlen, int *dataoutlen) {
+	
+	if (activateField) {
+		cmdc |= ISO14A_CONNECT | ISO14A_CLEAR_TRACE;
+	}
+
+	// "Command APDU" length should be 5+255+1, but javacard's APDU buffer might be smaller - 133 bytes
+	// https://stackoverflow.com/questions/32994936/safe-max-java-card-apdu-data-command-and-respond-size
+	// here length USB_CMD_DATA_SIZE=512
+	// timeout must be authomatically set by "get ATS"
+	UsbCommand c = {CMD_READER_ISO_14443a, {ISO14A_APDU | ISO14A_NO_DISCONNECT | cmdc, (datainlen & 0xFFFF), 0}}; 
+	memcpy(c.d.asBytes, datain, datainlen);
+	SendCommand(&c);
+	
+    uint8_t *recv;
+    UsbCommand resp;
+
+	if (activateField) {
+		if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
+			PrintAndLog("APDU ERROR: Proxmark connection timeout.");
+			return 1;
+		}
+		if (resp.arg[0] != 1) {
+			PrintAndLog("APDU ERROR: Proxmark error %d.", resp.arg[0]);
+			return 1;
+		}
+	}
+
+    if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
+        recv = resp.d.asBytes;
+        int iLen = resp.arg[0];
+		uint8_t res = resp.arg[1];
+		
+		int dlen = iLen - 2;
+		if (dlen < 0)
+			dlen = 0;
+		*dataoutlen += dlen;
+		
+		if (maxdataoutlen && *dataoutlen > maxdataoutlen) {
+			PrintAndLog("APDU ERROR: Buffer too small(%d). Needs %d bytes", *dataoutlen, maxdataoutlen);
+			return 2;
+		}
+		
+        if(!iLen) {
+			PrintAndLog("APDU ERROR: No APDU response.");
+            return 1;
+		}
+		
+		// check block TODO
+		if (iLen == -2) {
+			PrintAndLog("APDU ERROR: Block type mismatch.");
+			return 2;
+		}
+
+		memcpy(dataout, recv, dlen);
+		
+		// CRC Check
+		if (iLen == -1) {
+			PrintAndLog("APDU ERROR: ISO 14443A CRC error.");
+			return 3;
+		}
+	}	
+
+	return 0;
+}
+
+
 int ExchangeAPDU14a(uint8_t *datain, int datainlen, bool activateField, bool leaveSignalON, uint8_t *dataout, int maxdataoutlen, int *dataoutlen) {
 	uint16_t cmdc = 0;
 	int dlen;
 	*dataoutlen = 0;
 	
+	int res = CmdExchangeAPDU(datain, datainlen, activateField, dataout, maxdataoutlen, dataoutlen);
+//start refactoring...
 	if (activateField) {
 		cmdc |= ISO14A_CONNECT | ISO14A_CLEAR_TRACE;
 	}
@@ -830,7 +899,7 @@ int ExchangeAPDU14a(uint8_t *datain, int datainlen, bool activateField, bool lea
 				*dataoutlen += dlen;
 				
 				recv1 = resp1.d.asBytes;
-				printf("vlen:%d dlen:%d\n", resp1.arg[0] & 0xFFFF, dlen);
+				printf("dlen:%d\n", dlen);
 				
 				if (maxdataoutlen && *dataoutlen > maxdataoutlen) {
 					PrintAndLog("APDU ERROR: Buffer too small(%d). Needs %d bytes", *dataoutlen, maxdataoutlen);