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, 51 deletions

diff --git a/esp8266/modules/ds18x20.py b/esp8266/modules/ds18x20.py
deleted file mode 100644
index bf06094835..0000000000
--- a/esp8266/modules/ds18x20.py
+++ /dev/null
@@ -1,51 +0,0 @@
-# DS18x20 temperature sensor driver for MicroPython.
-# MIT license; Copyright (c) 2016 Damien P. George
-
-from micropython import const
-
-_CONVERT = const(0x44)
-_RD_SCRATCH = const(0xbe)
-_WR_SCRATCH = const(0x4e)
-
-class DS18X20:
-    def __init__(self, onewire):
-        self.ow = onewire
-        self.buf = bytearray(9)
-
-    def scan(self):
-        return [rom for rom in self.ow.scan() if rom[0] == 0x10 or rom[0] == 0x28]
-
-    def convert_temp(self):
-        self.ow.reset(True)
-        self.ow.writebyte(self.ow.SKIP_ROM)
-        self.ow.writebyte(_CONVERT)
-
-    def read_scratch(self, rom):
-        self.ow.reset(True)
-        self.ow.select_rom(rom)
-        self.ow.writebyte(_RD_SCRATCH)
-        self.ow.readinto(self.buf)
-        if self.ow.crc8(self.buf):
-            raise Exception('CRC error')
-        return self.buf
-
-    def write_scratch(self, rom, buf):
-        self.ow.reset(True)
-        self.ow.select_rom(rom)
-        self.ow.writebyte(_WR_SCRATCH)
-        self.ow.write(buf)
-
-    def read_temp(self, rom):
-        buf = self.read_scratch(rom)
-        if rom[0] == 0x10:
-            if buf[1]:
-                t = buf[0] >> 1 | 0x80
-                t = -((~t + 1) & 0xff)
-            else:
-                t = buf[0] >> 1
-            return t - 0.25 + (buf[7] - buf[6]) / buf[7]
-        else:
-            t = buf[1] << 8 | buf[0]
-            if t & 0x8000: # sign bit set
-                t = -((t ^ 0xffff) + 1)
-            return t / 16