examples: Add example of I2C usage, taking PyBoard accelerometer as subject.

This commit is contained in:
Paul Sokolovsky 2015-10-28 21:04:03 +03:00
parent f3b1a933fc
commit a2e0d92eeb
1 changed files with 33 additions and 0 deletions

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examples/accel_i2c.py Normal file
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# This is an example on how to access accelerometer on
# PyBoard directly using I2C bus. As such, it's more
# intended to be an I2C example, rather than accelerometer
# example. For the latter, using pyb.Accel class is
# much easier.
import pyb
import time
# Accelerometer needs to be powered on first. Even
# though signal is called "AVDD", and there's separate
# "DVDD", without AVDD, it won't event talk on I2C bus.
accel_pwr = pyb.Pin("MMA_AVDD")
accel_pwr.value(1)
i2c = pyb.I2C(1)
addrs = i2c.scan()
print("Scanning devices:", [hex(x) for x in addrs])
if 0x4c not in addrs:
print("Accelerometer is not detected")
ACCEL_ADDR = 0x4c
ACCEL_AXIS_X_REG = 0
ACCEL_MODE_REG = 7
# Now activate measurements
i2c.mem_write(b"\x01", ACCEL_ADDR, ACCEL_MODE_REG)
print("Try to move accelerometer and watch the values")
while True:
val = i2c.mem_read(1, ACCEL_ADDR, ACCEL_AXIS_X_REG)
print(val[0])
time.sleep(1)