Micropython

The Pyboard comes with 4 on board LEDs, in this example we will flash them on and off, the example was written in uPyCraft

Pinouts

Parts List

Code

First of all the various methods from the official docs

LED.intensity([value])

Get or set the LED intensity. Intensity ranges between 0 (off) and 255 (full on). If no argument is given, return the LED intensity. If an argument is given, set the LED intensity and return None.

Note: Only LED(3) and LED(4) can have a smoothly varying intensity, and they use timer PWM to implement it. LED(3) uses Timer(2) and LED(4) uses Timer(3). These timers are only configured for PWM if the intensity of the relevant LED is set to a value between 1 and 254. Otherwise the timers are free for general purpose use.

LED.off()

Turn the LED off.

LED.on()

Turn the LED on, to maximum intensity.

LED.toggle()

Toggle the LED between on (maximum intensity) and off. If the LED is at non-zero intensity then it is considered “on” and toggle will turn it off.

Now for the example showing this

[codesyntax lang=”python”]

from pyb import LED
import time

led1 = LED(1) # 1=red, 2=green, 3=yellow, 4=blue
led1.toggle()
led1.on()
time.sleep(1)
led1.off()
time.sleep(1)

led2 = LED(2) # 1=red, 2=green, 3=yellow, 4=blue
led2.toggle()
led2.on()
time.sleep(1)
led2.off()
time.sleep(1)

led3 = LED(3) # 1=red, 2=green, 3=yellow, 4=blue
led3.toggle()
led3.on()
time.sleep(1)
led3.off()
time.sleep(1)

led4 = LED(4) # 1=red, 2=green, 3=yellow, 4=blue
led4.toggle()
led4.on()
time.sleep(1)
led4.off()
time.sleep(1)

# LEDs 3 and 4 support PWM intensity (0-255)
LED(4).intensity()    # get intensity
LED(4).intensity(25) # set intensity to 25

[/codesyntax]

This is a simple very short code example in which we show how to create a basic I2CScanner in Micropython using the uPyCraft IDE for a Pyboard

The arduino equivalent is one that I use frequently and is one of the most useful sketches for figuring out why a sensor may not be working correctly with a library or code – usually because the default I2C address differs from the sensor address that you buy

Layout

An example connecting a sensor to a Pyboard

Code

[codesyntax lang=”python”]

from pyb import I2C

i2c = I2C(1, I2C.MASTER, baudrate=100000)
print('Scan i2c bus...')
devices = i2c.scan()

if len(devices) == 0:
  print("No i2c device !")
else:
  print('i2c devices found:',len(devices))
  
for device in devices:  
  print("Decimal address: ",device)
  print("Hex address: ",hex(device))

[/codesyntax]

Output

All going well you should output like the following in uPyCraft – this is a TMP175 connected to a PyBoard (not a BMP180 as the layout earlier)

Ready to download this file,please wait!
…
download ok
exec(open(‘i2cscanner.py’).read(),globals())
Scan i2c bus…
i2c devices found: 1
Decimal address: 55
Hex address: 0x37
>>>