Arduino Portenta H7 MicroPython Cheat Sheet

Goals

This article is a collection of mini-guides and API calls that can help you get started with the Arduino Portenta H7 board. You can also visit the documentation product page for more in-depth tutorials.

Core

The Portenta H7 uses the Arduino Mbed OS Portenta Boards core.

Installation

OpenMV

Arduino supports the OpenMV build of MicroPython to be used with the Portenta H7. To install it on your board, you can check out the guide below:

• Installing the Arduino Portenta H7 with MicroPython

Potential Issues

Sometimes the board is not detected even when the board is connected to your computer. This can be solved through the following steps:

1. Disconnect the board from your computer by removing the USB cable.
2. Reconnect the board to your computer.
3. If it still doesn't show up, double-press the reset button, to activate the bootloader mode.
4. Re-install the OpenMV firmware

Libraries

Some really useful MicroPython libraries in OpenMV are

pyb

machine

Pins

The below graphic shows the MKR pins available on the board. For a more detailed view that also shows the pins available through the high density connector, please visit the product page.

Pins in OpenMV

Most of the pins are referred to via their port name or their function in OpenMV. Please refer to the list below to see which function corresponds to which port on the Portenta H7.

I/O Pins

To access the I/O pins, you can use the

Pin

pyb

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1from pyb import Pin

To reference a pin on the Portenta, you can use the

Pin()

mode

Pin.IN

Pin.OUT_PP

Pin.OUT_OD

Pin.AF_PP

Pin.AF_OD

Pin.ANALOG

pull

Pin.PULL_NONE

Pin.PULL_UP

Pin.PULL_DOWN

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1pin0 = Pin('P0', mode, pull)

To get the logic level of a pin, call

.value()

LOW

HIGH

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1pin0.value()

PWM

To use PWM, you import the

pyb

time

Pin

Timer

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1import pyb
2import time
3from pyb import Pin, Timer

First you need to choose the pin you want to use PWM with.

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1pin1 = Pin("PC6", Pin.OUT_PP, Pin.PULL_NONE)

Create a timer for the PWM, where you set the ID and the frequency.

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1timer1 = Timer(3, freq=1000)

Then you need to start a PWM channel with the timer object.

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1channel1 = timer1.channel(1, Timer.PWM, pin=pin1, pulse_width=0)

Get or set the pulse width value on a channel. To get, pass no arguments. To set, give a value as an argument.

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1channel1.pulse_width(Width)

RGB LED

The Portenta H7 has built-in RGB that can be used as feedback for applications. Using the

pyb

For this you will use the

pyb

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1import pyb

Now you can easily define the different colors of the built in LED.

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1redLED = pyb.LED(1)
2greenLED = pyb.LED(2)
3blueLED = pyb.LED(3)

And then control them in our script.

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1redLED.on()
2redLED.off()
3
4greenLED.on()
5greenLED.off()
6
7blueLED.on()
8blueLED.off()

You could also set a custom intensity for our LED lights. This ranges between the values 0 (off) and 255 (full on). Below you can see an example of how to set the intensity on our different LED lights.

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1redLED.intensity(128)
2greenLED.intensity(64)
3blueLED.intensity(50)

If no argument is given in the

.intensity()

Communication

Like other Arduino® products, the Portenta H7 features dedicated pins for different protocols.

SPI

The pins used for SPI on the Portenta H7 are the following:

You can refer to the pinout above to find them on the board.

First, you have to import the relevant module from

pyb

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1from pyb import SPI

When you initialize SPI, the only thing you need to state is the bus, which will always be

2

SPI.MASTER

SPI.SLAVE

baudrate

Polarity

Phase

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1spi = SPI(2, SPI.MASTER, baudrate=100000, polarity=0, phase=0)

Now, if you want to send data over SPI, you simply call

.send()

data

timeout

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1dataInt = 21
2dataBuffer = bytearray(4)
3spi.send(data, timeout=5000)

Similarly, if you want to receive data over SPI, you call

.recv()

data

timeout

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1dataInt = 0
2dataBuffer = bytearray(4)
3SPI.recv(data, timeout=5000)

I2C

The pins used for I2C (Inter-Integrated Circuit) on the Portenta H7 are the following:

You can refer to the pinout above to find them on the board.

To use the I2C, you import the relevant module.

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1from pyb import I2C

You can now create the I2C object. To create an I2C object you need to state the bus, this indicates what pins you will use for I2C. Giving bus a value of

3

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1i2c = I2C(3)

Now that the object is created, you can initialize it. You need to decide if your device is going to be a controller (I2C.MASTER) or a reader (I2C.SLAVE). If it is a reader device, you also need to set the

address

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1i2c.init(I2C.MASTER, addr=address, baudrate=100000)

To receive data on the bus, you call the

.recv()

data

addr

timeout

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1dataInt = 0
2dataBuffer = bytearray(4)
3receivedData = i2c.recv(data, addr=0, timeout=5000)
4Print(receivedData)

To send data on the bus, you can call the

.send()

data

addr

timeout

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1dataInt = 412
2dataBuffer = bytearray(4)
3i2c.send(data, addr=0, timeout=5000)

If you need to make sure that devices are connected to the I2C bus, you can use the

.scan()

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1i2c.scan()

UART

The pins used for UART on the Portenta H7 are the following:

You can refer to the pinout above to find them on the board.

To use the UART, you need to import the relevant module.

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1from pyb import UART

To create the UART object, you need to indicate the UART bus, the Portenta has 3 UART buses, but there is only on UART bus available to use with OpenMV through the boards pins.

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1uart = UART(1)

With the object created, you can initialize it with

init

baudrate

bits

parity

None

0

1

stop

flow

timeout

timeout_char

read_buf_len

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1uart.init(baudrate, bits=8, parity=None, stop=1, timeout=0, flow=0, timeout_char=0, read_buf_len=64)

To read from UART, you can call

.read()

bytes

bytes

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1array = bytearray(5)
2uart.read(array)
3print(array)

If you intend to write over UART, you can call

.write()

buffer

buffer

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1uart.write(buffer)

WIFI

To use Wi-Fi you first need to import the relevant library.

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1import network

Then you need to define the Wi-Fi networks SSID and put that in a variable. You must do the same for the networks password.

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1SSID=''
2PASSWORD=''

Next, you can create a WLAN network interface object. In the argument you can enter

network.STA_IF

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1wlan = network.WLAN(network.STA_IF)

To activate the network interface, you can simply call

.activate

True

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1wlan.active(True)

Now you can decide which network to connect to. Here it is where the

SSID

PASSWORD

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1wlan.connect(SSID, PASSWORD, timeout=30000)

If you need to troubleshoot, the connection

.status()

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1wlan.status()

Audio

If you want to use audio with the Portenta H7, you first need to include the

audio

micro_speech

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1import audio, micro_speech

Next you need to initialize the audio object. In the initialization you can decide how many

channels

gain_db

highpass

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1audio.init(channels=2, frequency=16000, gain_db=24, highpass=0.9883)

If you need to deinitialize the audio object, you can simply call

deint()

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1audio.deint()

To use micro_speech, you first need to create a micro_speech object. You can create this object in the variable

speech

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1speech = micro_speech.MicroSpeech()

Next you can start streaming audio into the

micro_speech

audio.start_streaming()

micro_speech

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1audio.start_streaming(speech.audio_callback)

If you need to stop the audio streaming, you can call

.stop_streaming()

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1audio.stop_streaming()

Conclusion

This cheat sheet is written as a quick reference mainly to look up the features of this product. For a more in-depth walk though experience please have a look at the other tutorials.