blob: feae4a3e313193bdc0550d14aa7b10be50a42cca [file] [log] [blame]
# Copyright 2014 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Allows creation of ADC interface for beaglebone devices."""
import glob
import os
class BBadcError(Exception):
"""Class for exceptions of BBadc."""
def __init__(self, msg, value=0):
"""BBadc constructor.
msg: string, message describing error in detail
value: integer, value of error when non-zero status returned. Default=0
super(BBAdcError, self).__init__(msg, value)
self.msg = msg
self.value = value
class BBadc(object):
"""Provides interface to ADC through beaglebone."""
ADC_ENABLE_COMMAND = 'echo cape-bone-iio > %s'
ADC_ENABLE_NODE = '/sys/devices/bone_capemgr.*/slots'
ADC_IN_NODE = '/sys/devices/ocp.*/helper.*/AIN*'
def __init__(self):
"""Enables ADC drvier."""
adc_nodes = glob.glob(BBadc.ADC_ENABLE_NODE)
for adc_node in adc_nodes:
os.system(BBadc.ADC_ENABLE_COMMAND % adc_node)
def read(self):
"""Reads ADC values.
ADC inputs from AIN0 to AIN7.
buffer = []
adc_in_nodes = glob.glob(BBadc.ADC_IN_NODE)
for adc_in in adc_in_nodes:
with open(adc_in, 'r') as f:
buffer.append(int(, 10))
return buffer