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##
## This file is part of the libsigrokdecode 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
##
# MEMSIC MXC6225XU protocol decoder
import sigrokdecode as srd
# Definitions of various bits in MXC6225XU registers.
status = {
# SH[1:0]
'sh': {
0b00: 'none',
0b01: 'shake left',
0b10: 'shake right',
0b11: 'undefined',
},
# ORI[1:0] and OR[1:0] (same format)
'ori': {
0b00: 'vertical in upright orientation',
0b01: 'rotated 90 degrees clockwise',
0b10: 'vertical in inverted orientation',
0b11: 'rotated 90 degrees counterclockwise',
},
# SHTH[1:0]
'shth': {
0b00: '0.5g',
0b01: '1.0g',
0b10: '1.5g',
0b11: '2.0g',
},
# SHC[1:0]
'shc': {
0b00: '16',
0b01: '32',
0b10: '64',
0b11: '128',
},
# ORC[1:0]
'orc': {
0b00: '16',
0b01: '32',
0b10: '64',
0b11: '128',
},
}
class Decoder(srd.Decoder):
api_version = 1
id = 'mxc6225xu'
name = 'MXC6225XU'
longname = 'MEMSIC MXC6225XU'
desc = 'Digital Thermal Orientation Sensor (DTOS) protocol.'
license = 'gplv2+'
inputs = ['i2c']
outputs = ['mxc6225xu']
probes = []
optional_probes = [
{'id': 'int', 'name': 'INT', 'desc': 'DTOS interrupt output pin'},
]
options = {}
annotations = [
['Text', 'Human-readable text'],
]
def __init__(self, **kwargs):
self.state = 'IDLE'
def start(self):
# self.out_proto = self.register(srd.OUTPUT_PYTHON)
self.out_ann = self.register(srd.OUTPUT_ANN)
def report(self):
pass
def putx(self, data):
self.put(self.ss, self.es, self.out_ann, data)
def handle_reg_0x00(self, b):
# XOUT: 8-bit x-axis acceleration output.
# Data is in 2's complement, values range from -128 to 127.
self.putx([0, ['XOUT: %d' % b]])
def handle_reg_0x01(self, b):
# YOUT: 8-bit y-axis acceleration output.
# Data is in 2's complement, values range from -128 to 127.
self.putx([0, ['YOUT: %d' % b]])
def handle_reg_0x02(self, b):
# STATUS: Orientation and shake status.
# Bits[7:7]: INT
int_val = (b >> 7) & 1
s = 'unchanged and no' if (int_val == 0) else 'changed or'
ann = 'INT = %d: Orientation %s shake event occured\n' % (int_val, s)
# Bits[6:5]: SH[1:0]
sh = (((b >> 6) & 1) << 1) | ((b >> 5) & 1)
ann += 'SH[1:0] = %s: Shake event: %s\n' % \
(bin(sh)[2:], status['sh'][sh])
# Bits[4:4]: TILT
tilt = (b >> 4) & 1
s = '' if (tilt == 0) else 'not '
ann += 'TILT = %d: Orientation measurement is %svalid\n' % (tilt, s)
# Bits[3:2]: ORI[1:0]
ori = (((b >> 3) & 1) << 1) | ((b >> 2) & 1)
ann += 'ORI[1:0] = %s: %s\n' % (bin(ori)[2:], status['ori'][ori])
# Bits[1:0]: OR[1:0]
or_val = (((b >> 1) & 1) << 1) | ((b >> 0) & 1)
ann += 'OR[1:0] = %s: %s\n' % (bin(or_val)[2:], status['ori'][or_val])
# ann += 'b = %s\n' % (bin(b))
self.putx([0, [ann]])
def handle_reg_0x03(self, b):
# DETECTION: Powerdown, orientation and shake detection parameters.
# Note: This is a write-only register.
# Bits[7:7]: PD
pd = (b >> 7) & 1
s = 'Do not power down' if (pd == 0) else 'Power down'
ann = 'PD = %d: %s the device (into a low-power state)\n' % (pd, s)
# Bits[6:6]: SHM
shm = (b >> 6) & 1
ann = 'SHM = %d: Set shake mode to %d\n' % (shm, shm)
# Bits[5:4]: SHTH[1:0]
shth = (((b >> 5) & 1) << 1) | ((b >> 4) & 1)
ann += 'SHTH[1:0] = %s: Set shake threshold to %s\n' \
% (bin(shth)[2:], status['shth'][shth])
# Bits[3:2]: SHC[1:0]
shc = (((b >> 3) & 1) << 1) | ((b >> 2) & 1)
ann += 'SHC[1:0] = %s: Set shake count to %s readings\n' \
% (bin(shc)[2:], status['shc'][shc])
# Bits[1:0]: ORC[1:0]
orc = (((b >> 1) & 1) << 1) | ((b >> 0) & 1)
ann += 'ORC[1:0] = %s: Set orientation count to %s readings\n' \
% (bin(orc)[2:], status['orc'][orc])
self.putx([0, [ann]])
# TODO: Fixup, this is copy-pasted from another PD.
# TODO: Handle/check the ACKs/NACKs.
def decode(self, ss, es, data):
cmd, databyte = data
# Store the start/end samples of this I2C packet.
self.ss, self.es = ss, es
# State machine.
if self.state == 'IDLE':
# Wait for an I2C START condition.
if cmd != 'START':
return
self.state = 'GET SLAVE ADDR'
self.block_start_sample = ss
elif self.state == 'GET SLAVE ADDR':
# Wait for an address write operation.
# TODO: We should only handle packets to the slave(?)
if cmd != 'ADDRESS WRITE':
return
self.state = 'GET REG ADDR'
elif self.state == 'GET REG ADDR':
# Wait for a data write (master selects the slave register).
if cmd != 'DATA WRITE':
return
self.reg = databyte
self.state = 'WRITE REGS'
elif self.state == 'WRITE REGS':
# If we see a Repeated Start here, it's a multi-byte read.
if cmd == 'START REPEAT':
self.state = 'READ REGS'
return
# Otherwise: Get data bytes until a STOP condition occurs.
if cmd == 'DATA WRITE':
handle_reg = getattr(self, 'handle_reg_0x%02x' % self.reg)
handle_reg(databyte)
self.reg += 1
# TODO: Check for NACK!
elif cmd == 'STOP':
# TODO
self.state = 'IDLE'
else:
pass # TODO
elif self.state == 'READ REGS':
# Wait for an address read operation.
# TODO: We should only handle packets to the slave(?)
if cmd == 'ADDRESS READ':
self.state = 'READ REGS2'
return
else:
pass # TODO
elif self.state == 'READ REGS2':
if cmd == 'DATA READ':
handle_reg = getattr(self, 'handle_reg_0x%02x' % self.reg)
handle_reg(databyte)
self.reg += 1
# TODO: Check for NACK!
elif cmd == 'STOP':
# TODO
self.state = 'IDLE'
else:
pass # TODO?
else:
raise Exception('Invalid state: %s' % self.state)
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