piface.py

Go to the documentation of this file.

#   Copyright 2012-2013 Eric Ptak - trouch.com
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.

from webiopi.utils.types import M_JSON
from webiopi.devices.digital.mcp23XXX import MCP23S17
from webiopi.decorators.rest import request, response


class PiFaceDigital():
    def __init__(self, board=0):
        mcp = MCP23S17(0, 0x20+board)
        mcp.writeRegister(mcp.getAddress(mcp.IODIR, 0), 0x00) # Port A as output
        mcp.writeRegister(mcp.getAddress(mcp.IODIR, 8), 0xFF) # Port B as input
        mcp.writeRegister(mcp.getAddress(mcp.GPPU,  0), 0x00) # Port A PU OFF
        mcp.writeRegister(mcp.getAddress(mcp.GPPU,  8), 0xFF) # Port B PU ON
        self.mcp = mcp
        self.board = board
        
    def __str__(self):
        return "PiFaceDigital(%d)" % self.board 

    def __family__(self):
        return "PiFaceDigital"
    
    def checkChannel(self, channel):
        if not channel in range(8):
            raise ValueError("Channel %d invalid" % channel)
    
    @request("GET", "digital/input/%(channel)d")
    @response("%d")
    def digitalRead(self, channel):
        self.checkChannel(channel)
        return not self.mcp.digitalRead(channel+8)
    
    @request("POST", "digital/output/%(channel)d/%(value)d")
    @response("%d")
    def digitalWrite(self, channel, value):
        self.checkChannel(channel)
        return self.mcp.digitalWrite(channel, value)
    
    @request("GET", "digital/output/%(channel)d")
    @response("%d")
    def digitalReadOutput(self, channel):
        self.checkChannel(channel)
        return self.mcp.digitalRead(channel)
    
    @request("GET", "digital/*")
    @response(contentType=M_JSON)
    def readAll(self):
        inputs = {}
        outputs = {}
        for i in range(8):
            inputs[i] = self.digitalRead(i)
            outputs[i] = self.digitalReadOutput(i)
        return {"input": inputs, "output": outputs}