feat: v0.3.5 — PN532 driver, NFC operational, pinout from config

pn532.py

@@ -0,0 +1,155 @@
+# ============================================================+
+# Identity IoT — PN532 NFC Driver for MicroPython
+# (c) Copyright : ae Aeonian Engineering Limited - Hong Kong
+# (c) Copyright : WIDE di D. Papa - Naples - Italy
+# ============================================================+
+
+import utime
+from machine import Pin, I2C
+
+PN532_I2C_ADDRESS            = 0x24
+PN532_CMD_GETFIRMWAREVERSION = 0x02
+PN532_CMD_SAMCONFIGURATION   = 0x14
+PN532_CMD_INLISTPASSIVETARGET= 0x4A
+PN532_CMD_INDATAEXCHANGE     = 0x40
+PN532_CMD_INRELEASE          = 0x52
+PN532_HOSTTOPN532            = 0xD4
+PN532_PN532TOHOST            = 0xD5
+
+
+class PN532Error(Exception):
+    pass
+
+
+class PN532_I2C:
+
+    def __init__(self, i2c: I2C, address: int = PN532_I2C_ADDRESS):
+        self._i2c  = i2c
+        self._addr = address
+
+        # Wake
+        try:
+            self._i2c.writeto(self._addr, bytes([0x00]))
+        except Exception:
+            pass
+        utime.sleep_ms(500)
+
+        fw = self.get_firmware_version()
+        if not fw:
+            raise PN532Error('PN532 not found or not responding')
+        print('[pn532] firmware: IC=%02x Ver=%d Rev=%d' % (fw['ic'], fw['ver'], fw['rev']))
+        self._sam_config()
+
+    def _build_frame(self, cmd: list) -> bytes:
+        body   = [PN532_HOSTTOPN532] + cmd
+        length = len(body)
+        lcs    = (~length + 1) & 0xFF
+        dcs    = (~(sum(body) & 0xFF) + 1) & 0xFF
+        return bytes([0x00, 0x00, 0xFF, length, lcs] + body + [dcs, 0x00])
+
+    def _send_command(self, cmd: list):
+        frame = self._build_frame(cmd)
+        self._i2c.writeto(self._addr, frame)
+
+    def _wait_ready(self, timeout=1000) -> bool:
+        t = timeout
+        while t > 0:
+            try:
+                b = self._i2c.readfrom(self._addr, 1)
+                if b[0] == 0x01:
+                    return True
+            except Exception:
+                pass
+            utime.sleep_ms(10)
+            t -= 10
+        return False
+
+    def _read_response(self, length=32, timeout=1000):
+        """Read after command — PN532 sends ACK then response."""
+        # Read ACK (6 bytes + status)
+        if not self._wait_ready(timeout):
+            return None
+        self._i2c.readfrom(self._addr, 7)  # status + ACK frame
+        utime.sleep_ms(10)
+
+        # Read response
+        if not self._wait_ready(timeout):
+            return None
+        buf = self._i2c.readfrom(self._addr, length + 1)
+
+        # Parse: skip status byte, find data after header
+        # Frame: [status][0x00][0x00][0xFF][len][lcs][TFI][cmd+1][data...][dcs][0x00]
+        if len(buf) < 8:
+            return None
+        data_len = buf[4]  # length field
+        if data_len < 2:
+            return bytes()
+        # data starts at index 7 (after status+preamble+start+len+lcs+TFI)
+        data = buf[7:7 + data_len - 1]
+        return bytes(data)
+
+    def _sam_config(self):
+        self._send_command([PN532_CMD_SAMCONFIGURATION, 0x01, 0x14, 0x01])
+        self._read_response(timeout=200)
+
+    def get_firmware_version(self) -> dict:
+        try:
+            self._send_command([PN532_CMD_GETFIRMWAREVERSION])
+            # First read: ACK frame
+            if not self._wait_ready(500):
+                return None
+            self._i2c.readfrom(self._addr, 7)  # status + ACK
+            utime.sleep_ms(10)
+            # Second read: response frame
+            if not self._wait_ready(500):
+                return None
+            buf = self._i2c.readfrom(self._addr, 14)
+            # buf[0]=status, buf[1..3]=preamble, buf[4]=len, buf[5]=lcs
+            # buf[6]=TFI(0xD5), buf[7]=cmd(0x03), buf[8..11]=IC,Ver,Rev,Support
+            if len(buf) < 12:
+                return None
+            return {
+                'ic':      buf[8],
+                'ver':     buf[9],
+                'rev':     buf[10],
+                'support': buf[11],
+            }
+        except Exception as e:
+            print('[pn532] fw error:', e)
+            return None
+
+    def read_passive_target(self, timeout=1000) -> bytes:
+        """Wait for ISO14443A card. Returns UID bytes or None."""
+        self._send_command([PN532_CMD_INLISTPASSIVETARGET, 0x01, 0x00])
+        resp = self._read_response(length=32, timeout=timeout)
+        if not resp or len(resp) < 6:
+            return None
+        if resp[0] != 0x01:
+            return None
+        uid_len = resp[4]
+        return bytes(resp[5:5 + uid_len])
+
+    def read_uid(self, timeout=500) -> bytes:
+        return self.read_passive_target(timeout=timeout)
+
+    def read_page(self, page: int) -> bytes:
+        self._send_command([PN532_CMD_INDATAEXCHANGE, 0x01, 0x30, page & 0xFF])
+        resp = self._read_response(length=16, timeout=500)
+        if not resp or len(resp) < 4:
+            return None
+        return bytes(resp[:4])
+
+    def write_page(self, page: int, data: bytes) -> bool:
+        if len(data) != 4:
+            raise PN532Error('write_page: data must be 4 bytes')
+        self._send_command([PN532_CMD_INDATAEXCHANGE, 0x01, 0xA2, page & 0xFF] + list(data))
+        resp = self._read_response(timeout=500)
+        return resp is not None
+
+    def release_target(self) -> bool:
+        try:
+            self._send_command([PN532_CMD_INRELEASE, 0x01])
+            self._read_response(timeout=200)
+            return True
+        except Exception:
+            return False