drivers/onewire: Move onewire.py, ds18x20.py from esp8266 to drivers.

These drivers can now be used by any port (so long as that port has the
_onewire driver from extmod/modonewire.c).

These drivers replace the existing 1-wire and DS18X20 drivers in the
drivers/onewire directory.  The existing ones were pyboard-specific and
not very efficient nor minimal (although the 1-wire driver was written in
pure Python it only worked at large enough CPU frequency).

This commit brings backwards incompatible API changes to the existing
1-wire drivers.  User code should be converted to use the new drivers, or
check out the old version of the code and keep a local copy (it should
continue to work unchanged).

1 files changed, 0 insertions, 91 deletions

diff --git a/esp8266/modules/onewire.py b/esp8266/modules/onewire.py
deleted file mode 100644
index 83318d1a47..0000000000
--- a/esp8266/modules/onewire.py
+++ /dev/null
@@ -1,91 +0,0 @@
-# 1-Wire driver for MicroPython on ESP8266
-# MIT license; Copyright (c) 2016 Damien P. George
-
-from micropython import const
-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, required=False):
-        reset = _ow.reset(self.pin)
-        if required and not reset:
-            raise OneWireError
-        return reset
-
-    def readbit(self):
-        return _ow.readbit(self.pin)
-
-    def readbyte(self):
-        return _ow.readbyte(self.pin)
-
-    def readinto(self, buf):
-        for i in range(len(buf)):
-            buf[i] = _ow.readbyte(self.pin)
-
-    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)