kumi/MicroPython_PN532
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remove i2c status byte

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This commit is contained in:
ladyada 2018-08-24 14:44:09 -04:00
parent fce5b57918
commit 29679ba8a3
1 changed files with 13 additions and 17 deletions
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26
adafruit_pn532.py
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@ -141,8 +141,8 @@ _GPIO_P33 = const(3)
_GPIO_P34 = const(4) _GPIO_P34 = const(4)
_GPIO_P35 = const(5) _GPIO_P35 = const(5)
_ACK = b'\x01\x00\x00\xFF\x00\xFF\x00' _ACK = b'\x00\x00\xFF\x00\xFF\x00'
_FRAME_START = b'\x01\x00\x00\xFF' _FRAME_START = b'\x00\x00\xFF'
class BusyError(Exception): class BusyError(Exception):
"""Base class for exceptions in this module.""" """Base class for exceptions in this module."""
@ -213,15 +213,15 @@ class PN532_I2C(object):
def _read_data(self, count): def _read_data(self, count):
"""Read a specified count of bytes from the PN532.""" """Read a specified count of bytes from the PN532."""
# Build a read request frame. # Build a read request frame.
frame = bytearray(count) frame = bytearray(count+1)
with self._i2c: with self._i2c:
#self._i2c.readinto(frame, end=1) # read ready byte! self._i2c.readinto(frame, end=1) # read ready byte!
#if frame[0] != 0x01: # not ready if frame[0] != 0x01: # not ready
# raise BusyError raise BusyError
self._i2c.readinto(frame) self._i2c.readinto(frame)
if self.debug: if self.debug:
print("Reading: ", [hex(i) for i in frame]) print("Reading: ", [hex(i) for i in frame[1:]])
return frame return frame[1:]
def _read_frame(self, length): def _read_frame(self, length):
"""Read a response frame from the PN532 of at most length bytes in size. """Read a response frame from the PN532 of at most length bytes in size.
@ -233,12 +233,8 @@ class PN532_I2C(object):
response = self._read_data(length+8) response = self._read_data(length+8)
if self.debug: if self.debug:
print('Read frame:', [hex(i) for i in response]) print('Read frame:', [hex(i) for i in response])
# Check frame starts with 0x01 and then has 0x00FF (preceeded by optional
# zeros).
if response[0] != 0x01:
raise RuntimeError('Response frame does not start with 0x01!')
# Swallow all the 0x00 values that preceed 0xFF. # Swallow all the 0x00 values that preceed 0xFF.
offset = 1 offset = 0
while response[offset] == 0x00: while response[offset] == 0x00:
offset += 1 offset += 1
if offset >= len(response): if offset >= len(response):
@ -263,18 +259,18 @@ class PN532_I2C(object):
if self._irq: if self._irq:
print("TODO IRQ") print("TODO IRQ")
else: else:
"""
status = bytearray(1) status = bytearray(1)
t = time.monotonic() t = time.monotonic()
while (time.monotonic() - t) < timeout: while (time.monotonic() - t) < timeout:
"""
with self._i2c: with self._i2c:
self._i2c.readinto(status) self._i2c.readinto(status)
if status == b'\0x01': if status == b'\0x01':
print(".ready.") print(".ready.")
return True return True
else: else:
time.sleep(0.1)
print(".busy.") print(".busy.")
time.sleep(0.1)
""" """
time.sleep(timeout) time.sleep(timeout)
return True return True