diff options
Diffstat (limited to 'drivers/onewire/ds18x20.py')
| -rw-r--r-- | drivers/onewire/ds18x20.py | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/onewire/ds18x20.py b/drivers/onewire/ds18x20.py index 272642239..ad2d9f52c 100644 --- a/drivers/onewire/ds18x20.py +++ b/drivers/onewire/ds18x20.py @@ -4,8 +4,9 @@ from micropython import const _CONVERT = const(0x44) -_RD_SCRATCH = const(0xbe) -_WR_SCRATCH = const(0x4e) +_RD_SCRATCH = const(0xBE) +_WR_SCRATCH = const(0x4E) + class DS18X20: def __init__(self, onewire): @@ -26,7 +27,7 @@ class DS18X20: self.ow.writebyte(_RD_SCRATCH) self.ow.readinto(self.buf) if self.ow.crc8(self.buf): - raise Exception('CRC error') + raise Exception("CRC error") return self.buf def write_scratch(self, rom, buf): @@ -40,12 +41,12 @@ class DS18X20: if rom[0] == 0x10: if buf[1]: t = buf[0] >> 1 | 0x80 - t = -((~t + 1) & 0xff) + 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) + if t & 0x8000: # sign bit set + t = -((t ^ 0xFFFF) + 1) return t / 16 |