User manual

MediaTek LinkIt™ Smart 7688 Developer's Guide

Page 61

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Then, call pin.write(0) to set the pin state to LOW or call pin.write(1) to set the pin

state to

HIGH. To make the Wi-Fi LED blink periodically, set pin 44 (WLED_N) to GPIO mode

and execute the following code:

import mraa

import time

# Refer to the pinout digram for the GPIO number to silk print mapping

# in this example the number 44 maps to Wi-Fi LED.

pin = mraa.Gpio(44)

pin.dir(mraa.DIR_OUT)

while True:

pin.write(1)

time.sleep(1)

pin.write(0)

time.sleep(1)

There’s another GPIO mode which is INPUT. It takes the digital signal input from the pin

and interprets it into 1 and 0. This example will continuously print out the value received

from

P10 on the board. You can short 3V3 and P10 to observe the change in values.

import mraa

import time

# Refer to the pinout digram for the GPIO number to silk print mapping

# in this example the number 2 maps to P10 on LinkIt Smart 7688 board

pin = mraa.Gpio(2)

pin.dir(mraa.DIR_IN)

while True:

print "P10 state:", pin.read()

time.sleep(0.3)

Finally, an interrupt service routine can be installed to the pin and invoked when the

values of the input pin P10 (GPIO2) has changed. Call

isr API with the trigger type you

want to register and the function to be called. Note that the function runs in a different

thread.

import mraa

import time

def callback(userdata):

print "interrupt triggered with userdata=", userdata

pin = mraa.Gpio(2)

pin.dir(mraa.DIR_IN)

pin.isr(mraa.EDGE_BOTH, callback, None)