Added support for extended frames, fixes adafruit#38 adafruit#39 #5

solhuebner · Aug 21, 2020 · 8ddae6f · 8ddae6f
1 parent 12d6cf7
commit 8ddae6f
Showing 1 changed file with 28 additions and 11 deletions.
diff --git a/Adafruit_PN532.cpp b/Adafruit_PN532.cpp
@@ -19,6 +19,8 @@
 
     @section  HISTORY
 
+    v2.2 - Added support for extended frames
+
     v2.1 - Added NTAG2xx helper functions
 
     v2.0 - Refactored to add I2C support from Adafruit_NFCShield_I2C library.
@@ -598,7 +600,7 @@ bool Adafruit_PN532::readPassiveTargetID(uint8_t cardbaudrate, uint8_t *uid,
 /**************************************************************************/
 bool Adafruit_PN532::inDataExchange(uint8_t *send, uint8_t sendLength,
                                     uint8_t *response,
-                                    uint8_t *responseLength) {
+                                    uint16_t *responseLength) {
   if (sendLength > PN532_PACKBUFFSIZ - 2) {
 #ifdef PN532DEBUG
     PN532DEBUGPRINT.println(F("APDU length too long for packet buffer"));
@@ -611,7 +613,7 @@ bool Adafruit_PN532::inDataExchange(uint8_t *send, uint8_t sendLength,
     #endif
     return false;
   }
-  uint8_t i;
+  uint16_t i;
 
   pn532_packetbuffer[0] = 0x40; // PN532_COMMAND_INDATAEXCHANGE;
   pn532_packetbuffer[1] = _inListedTag;
@@ -637,18 +639,33 @@ bool Adafruit_PN532::inDataExchange(uint8_t *send, uint8_t sendLength,
 
   if (pn532_packetbuffer[0] == 0 && pn532_packetbuffer[1] == 0 &&
       pn532_packetbuffer[2] == 0xff) {
-    uint8_t length = pn532_packetbuffer[3];
-    if (pn532_packetbuffer[4] != (uint8_t)(~length + 1)) {
+
+    uint16_t length;
+    uint8_t checksumOffset;
+    uint8_t lengthChecksum;
+    if (pn532_packetbuffer[3] == PN532_EXTENDED_FRAME_FIXED_VALUE &&
+        pn532_packetbuffer[4] == PN532_EXTENDED_FRAME_FIXED_VALUE) {
+      //It's an extended frame
+      length = (((uint16_t) pn532_packetbuffer[5]) << 8) | pn532_packetbuffer[6];
+      lengthChecksum = (uint8_t)(~(pn532_packetbuffer[5]+pn532_packetbuffer[6])+1);
+      checksumOffset = 3; //length is encoded in three more bytes (two fixed values 0xFF and an additional octet for the length itself)
+    } else {
+      length = pn532_packetbuffer[3];
+      lengthChecksum = (uint8_t)(~length+1);
+      checksumOffset = 0;
+    }
+
+    if (pn532_packetbuffer[checksumOffset+4]!=lengthChecksum) {
 #ifdef PN532DEBUG
       PN532DEBUGPRINT.println(F("Length check invalid"));
       PN532DEBUGPRINT.println(length, HEX);
       PN532DEBUGPRINT.println((~length) + 1, HEX);
 #endif
       return false;
     }
-    if (pn532_packetbuffer[5] == PN532_PN532TOHOST &&
-        pn532_packetbuffer[6] == PN532_RESPONSE_INDATAEXCHANGE) {
-      if ((pn532_packetbuffer[7] & 0x3f) != 0) {
+    if (pn532_packetbuffer[checksumOffset+5]==PN532_PN532TOHOST &&
+        pn532_packetbuffer[checksumOffset+6]==PN532_RESPONSE_INDATAEXCHANGE) {
+      if ((pn532_packetbuffer[checksumOffset+7] & 0x3f)!=0) {
 #ifdef PN532DEBUG
         PN532DEBUGPRINT.println(F("Status code indicates an error"));
 #endif
@@ -662,7 +679,7 @@ bool Adafruit_PN532::inDataExchange(uint8_t *send, uint8_t sendLength,
       }
 
       for (i = 0; i < length; ++i) {
-        response[i] = pn532_packetbuffer[8 + i];
+        response[i] = pn532_packetbuffer[checksumOffset+8+i];
       }
       *responseLength = length;
 
@@ -1580,7 +1597,7 @@ bool Adafruit_PN532::waitready(uint16_t timeout) {
     @param  n         Number of bytes to be read
 */
 /**************************************************************************/
-void Adafruit_PN532::readdata(uint8_t *buff, uint8_t n) {
+void Adafruit_PN532::readdata(uint8_t *buff, uint16_t n) {
   if (spi_dev) {
     uint8_t cmd = PN532_SPI_DATAREAD;
 
@@ -1604,10 +1621,10 @@ void Adafruit_PN532::readdata(uint8_t *buff, uint8_t n) {
     PN532DEBUGPRINT.print(F("Reading: "));
 #endif
     // Start read (n+1 to take into account leading 0x01 with I2C)
-    WIRE.requestFrom((uint8_t)PN532_I2C_ADDRESS, (uint8_t)(n + 2));
+    WIRE.requestFrom((uint8_t)PN532_I2C_ADDRESS, (uint16_t)(n + 2));
     // Discard the leading 0x01
     i2c_recv();
-    for (uint8_t i = 0; i < n; i++) {
+    for (uint16_t i = 0; i < n; i++) {
       delay(1);
       buff[i] = i2c_recv();
 #ifdef PN532DEBUG