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##
## This file is part of the sigrok project.
##
## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
##
# Melexis MLX90614 Infrared Thermometer protocol decoder
import sigrokdecode as srd
class Decoder(srd.Decoder):
api_version = 1
id = 'mlx90614'
name = 'MLX90614'
longname = 'Melexis MLX90614'
desc = 'Infrared Thermometer protocol.'
license = 'gplv2+'
inputs = ['i2c']
outputs = ['mlx90614']
probes = []
optional_probes = []
options = {}
annotations = [
['Celsius', 'Temperature in degrees Celsius'],
['Kelvin', 'Temperature in degrees Kelvin'],
]
def __init__(self, **kwargs):
self.state = 'IGNORE START REPEAT'
self.data = []
def start(self, metadata):
# self.out_proto = self.add(srd.OUTPUT_PROTO, 'mlx90614')
self.out_ann = self.add(srd.OUTPUT_ANN, 'mlx90614')
def report(self):
pass
def putx(self, data):
self.put(self.ss, self.es, self.out_ann, data)
# Quick hack implementation! This needs to be improved a lot!
def decode(self, ss, es, data):
cmd, databyte = data
# State machine.
if self.state == 'IGNORE START REPEAT':
if cmd != 'START REPEAT':
return
self.state = 'IGNORE ADDRESS WRITE'
elif self.state == 'IGNORE ADDRESS WRITE':
if cmd != 'ADDRESS WRITE':
return
self.state = 'GET TEMPERATURE'
elif self.state == 'GET TEMPERATURE':
if len(self.data) == 0:
self.data.append(databyte)
self.ss = ss
elif len(self.data) == 1:
self.data.append(databyte)
self.es = es
else:
kelvin = (self.data[0] | (self.data[1] << 8)) * 0.02
celsius = kelvin - 273.15
self.putx([0, ['Temperature: %3.2f °C' % celsius]])
self.putx([1, ['Temperature: %3.2f °K' % kelvin]])
self.state = 'IGNORE START REPEAT'
self.data = []
else:
raise Exception('Invalid state: %d' % self.state)
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