diff options
Diffstat (limited to 'esp8266/scripts/onewire.py')
-rw-r--r-- | esp8266/scripts/onewire.py | 127 |
1 files changed, 0 insertions, 127 deletions
diff --git a/esp8266/scripts/onewire.py b/esp8266/scripts/onewire.py deleted file mode 100644 index 686616950a..0000000000 --- a/esp8266/scripts/onewire.py +++ /dev/null @@ -1,127 +0,0 @@ -# 1-Wire driver for MicroPython on ESP8266 -# MIT license; Copyright (c) 2016 Damien P. George - -import _onewire as _ow - -class OneWireError(Exception): - pass - -class OneWire: - SEARCH_ROM = const(0xf0) - MATCH_ROM = const(0x55) - SKIP_ROM = const(0xcc) - - def __init__(self, pin): - self.pin = pin - self.pin.init(pin.OPEN_DRAIN) - - def reset(self): - return _ow.reset(self.pin) - - def readbit(self): - return _ow.readbit(self.pin) - - def readbyte(self): - return _ow.readbyte(self.pin) - - def read(self, count): - buf = bytearray(count) - for i in range(count): - buf[i] = _ow.readbyte(self.pin) - return buf - - def writebit(self, value): - return _ow.writebit(self.pin, value) - - def writebyte(self, value): - return _ow.writebyte(self.pin, value) - - def write(self, buf): - for b in buf: - _ow.writebyte(self.pin, b) - - def select_rom(self, rom): - self.reset() - self.writebyte(MATCH_ROM) - self.write(rom) - - def scan(self): - devices = [] - diff = 65 - rom = False - for i in range(0xff): - rom, diff = self._search_rom(rom, diff) - if rom: - devices += [rom] - if diff == 0: - break - return devices - - def _search_rom(self, l_rom, diff): - if not self.reset(): - return None, 0 - self.writebyte(SEARCH_ROM) - if not l_rom: - l_rom = bytearray(8) - rom = bytearray(8) - next_diff = 0 - i = 64 - for byte in range(8): - r_b = 0 - for bit in range(8): - b = self.readbit() - if self.readbit(): - if b: # there are no devices or there is an error on the bus - return None, 0 - else: - if not b: # collision, two devices with different bit meaning - if diff > i or ((l_rom[byte] & (1 << bit)) and diff != i): - b = 1 - next_diff = i - self.writebit(b) - if b: - r_b |= 1 << bit - i -= 1 - rom[byte] = r_b - return rom, next_diff - - def crc8(self, data): - return _ow.crc8(data) - -class DS18B20: - CONVERT = const(0x44) - RD_SCRATCH = const(0xbe) - WR_SCRATCH = const(0x4e) - - def __init__(self, onewire): - self.ow = onewire - - def scan(self): - return [rom for rom in self.ow.scan() if rom[0] == 0x28] - - def convert_temp(self): - if not self.ow.reset(): - raise OneWireError - self.ow.writebyte(SKIP_ROM) - self.ow.writebyte(CONVERT) - - def read_scratch(self, rom): - if not self.ow.reset(): - raise OneWireError - self.ow.select_rom(rom) - self.ow.writebyte(RD_SCRATCH) - buf = self.ow.read(9) - if self.ow.crc8(buf): - raise OneWireError - return buf - - def write_scratch(self, rom, buf): - if not self.ow.reset(): - raise OneWireError - self.ow.select_rom(rom) - self.ow.writebyte(WR_SCRATCH) - self.ow.write(buf) - - def read_temp(self, rom): - buf = self.read_scratch(rom) - return (buf[1] << 8 | buf[0]) / 16 |