kiln_controller/kiln/breakout.py

59 wiersze
1.6 KiB
Python

import smbus
import struct
from collections import namedtuple
Status = namedtuple('Status', 'ignite flame motor main_temp ambient weight aux_temp0 aux_temp1')
class Breakout(object):
fmt = struct.Struct('<BBH5f')
def __init__(self, addr, bus=1):
self.bus = smbus.SMBus(1)
self.addr = addr
@property
def status(self):
while True:
try:
chars = map(chr, self.bus.read_i2c_block_data(self.addr, 0, self.fmt.size))
return Status._make(self.fmt.unpack(''.join(chars)))
except IOError:
#ignore IOError due to i2c timeout
pass
def __repr__(self):
return repr(self.status)
def _get_cmd(self, cmd, fmt='f'):
s = struct.Struct('<'+fmt)
while True:
try:
data = self.bus.read_i2c_block_data(self.addr, ord(cmd), s.size)
return s.unpack(''.join(map(chr, data)))[0]
except IOError:
#ignore IOError due to i2c timeout
pass
def _set_cmd(self, cmd, value, fmt='f'):
out = map(ord, struct.pack('<'+fmt, value))
self.bus.write_i2c_block_data(self.addr, ord(cmd), out)
@property
def motor(self):
return self._get_cmd('M', fmt='H')
@motor.setter
def motor(self, pos):
self._set_cmd('M', pos, fmt='H')
@property
def temperature(self):
return self._get_cmd('T', fmt='f')
@property
def ignite(self):
return self._get_cmd('I', fmt='B')
@ignite.setter
def ignite(self, output):
self._set_cmd('I', output, fmt='B')