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"""Arduino-like library for Python on BeagleBone"""
import time
HIGH = "HIGH"
LOW = "LOW"
OUTPUT = "OUTPUT"
INPUT = "INPUT"
pinList = [] # needed for unexport()
startTime = time.time() # needed for millis()
digitalPinDef = {
"P8.3": 38,
"P8.4": 39,
"P8.5": 34,
"P8.6": 35,
"P8.11": 45,
"P8.12": 44,
"P8.14": 26,
"P8.15": 47,
"P8.16": 46,
"P8.17": 27,
"P8.18": 65,
"P8.20": 63,
"P8.21": 62,
"P8.22": 37,
"P8.23": 36,
"P8.24": 33,
"P8.25": 32,
"P8.26": 61,
"P8.27": 86,
"P8.28": 88,
"P8.29": 87,
"P8.30": 89,
"P8.39": 76,
"P8.40": 77,
"P8.41": 74,
"P8.42": 75,
"P8.43": 72,
"P8.44": 73,
"P8.45": 70,
"P8.46": 71,
"P9.12": 60,
"P9.15": 48,
"P9.23": 49,
"P9.25": 117,
"P9.27": 115,
"P9.42": 7}
analogPinDef = {
"P9.33": "ain4",
"P9.35": "ain6",
"P9.36": "ain5",
"P9.37": "ain2",
"P9.38": "ain3",
"P9.39": "ain0",
"P9.40": "ain1"}
def pinMode(pin, direction):
"""pinMode(pin, direction) opens (exports) a pin for use and
sets the direction"""
if pin in digitalPinDef:
fw = file("/sys/class/gpio/export", "w")
fw.write("%d" % (digitalPinDef[pin]))
fw.close()
fileName = "/sys/class/gpio/gpio%d/direction" % (digitalPinDef[pin])
fw = file(fileName, "w")
if direction == INPUT:
fw.write("in")
else:
fw.write("out")
fw.close()
pinList.append(digitalPinDef[pin])
else:
print "pinMode error: Pin " + pin + " is not defined as a digital I/O pin in the pin definition."
def digitalWrite(pin, status):
"""digitalWrite(pin, status) sets a pin HIGH or LOW"""
if pin in digitalPinDef:
fileName = "/sys/class/gpio/gpio%d/value" % (digitalPinDef[pin])
fw = file(fileName, "w")
if status == HIGH:
fw.write("1")
if status == LOW:
fw.write("0")
fw.close()
else:
print "digitalWrite error: Pin " + pin + " is not defined as a digital I/O pin in the pin definition."
def digitalRead(pin):
"""digitalRead(pin) returns HIGH or LOW for a given pin."""
if pin in digitalPinDef:
fileName = "/sys/class/gpio/gpio%d/value" % (digitalPinDef[pin])
fw = file(fileName, "r")
inData = fw.read()
fw.close()
if inData == "0\n":
return LOW
if inData == "1\n":
return HIGH
else:
print "digitalRead error: Pin " + pin + " is not defined as a digital I/O pin in the pin definition."
return -1;
def analogRead(pin):
"""analogRead(pin) returns analog value for a given pin."""
if pin in analogPinDef:
fileName = "/sys/devices/platform/tsc/" + (analogPinDef[pin])
fw = file(fileName, "r")
return fw.read()
fw.close()
else:
print "analogRead error: Pin " + pin + " is not defined as an analog in pin in the pin definition."
return -1;
def pinUnexport(pin):
"""pinUnexport(pin) closes a pin in sysfs. This is susally
called by cleanup() when a script is exiting."""
fw = file("/sys/class/gpio/unexport", "w")
fw.write("%d" % (pin))
fw.close()
def cleanup():
""" takes care of stepping through pins that were set with
pinMode and unExports them. Prints result"""
def find_key(dic, val):
return [k for k, v in dic.iteritems() if v == val][0]
print ""
print "Cleaning up. Unexporting the following pins:",
for pin in pinList:
pinUnexport(pin)
print find_key(digitalPinDef, pin),
def delay(millis):
"""delay(millis) sleeps the script for a given number of
milliseconds"""
time.sleep(millis/1000.0)
def millis():
"""millis() returns an int for the number of milliseconds since
the script started."""
return int((time.time() - startTime) * 1000)
def run(setup, main): # from PyBBIO by Alexander Hiam - ahiam@marlboro.edu - www.alexanderhiam.com https://github.com/alexanderhiam/PyBBIO
""" The main loop; must be passed a setup and a main function.
First the setup function will be called once, then the main
function wil be continuously until a stop signal is raised,
e.g. CTRL-C or a call to the stop() function from within the
main function. """
try:
setup()
while (True):
main()
except KeyboardInterrupt:
# Manual exit signal, clean up and exit happy
cleanup()
except Exception, e:
# Something may have gone wrong, clean up and print exception
cleanup()
print e
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