This project shows how to interact with the Raspberry Pi GPIOs from a dashboard created using Arduino Cloud with an application programmed in Python. It can serve as an example to create your own applications that require access to RPI GPIOs and that can be ultimately controlled using a dashboard.
In this project I have used a Raspberry Pi 5 connected to an LED and a push button, both inserted in a breadboard. This is the diagram
Note: This project should work with any Raspberry Pi version and actually with any Linux-based machine that supports libgpiod. Please, drop your comments in Issues if it does not work with your board in order to review it.
The process to use this project is very straighforward:
- Create the Device and Thing in the Arduino Cloud and get the Arduino Cloud API Key
- Create your python environment
- Develop the python application
- Create the Arduino Cloud dashboard
- Test everything
Note: Before getting started, make sure that you have an Arduino Cloud account
Go to the Devices section of the Arduino IoT Cloud and click on + DEVICE.
Select Any Device and follow the instructions on the wizard.
Note: Save your
Device IDandSecret Keyas they will be used in your python code.
In your recently created device page, go to the Associated Thing section, click on Create Thing and rename it.
Note: You can also create the Thing from the Things list and associate it later.
Add the variables by clicking on the ADD button. At the end of the process, your list of variables should look like this.
| Name | Type | Description |
|---|---|---|
| button | Boolean | It will hold the status of the physical button |
| led | Boolean | The variable that we will use to act over the physical LED |
| test_value | Integer | This is a value that will change periodically in the application |
Note: All the variables have to be READ-WRITE. You can define the periodicity you wish or set them with the policy ON-CHANGE.
This is a screenshot for reference.
Now it is time to install the python dependencies in order to use Arduino Cloud. You have a full tutorial that describes the process in detail.
It can be summarized as follows:
- Install GPIOD library in the system
- Install the Python GPIOD package
- Install the Python Arduino Cloud packages
First, you have to install library in the system. If you are using Ubuntu or any other Debian-based machine, you can follow these instructions
sudo apt install gpiod libgpiod-dev libgpiod2 python3-libgpiod
Next, you have to install the PIP package. For that, my recommendation is that you install it in an isolated virtual environment. So you have to install the following packages
sudo apt install python3-pip python3-virtualenv
To create and activate the virtual environment, use the following code
cd <YOUR_PROJECT_FOLDER>
virtualenv venv
source venv/bin/activate
Note: The command
virtualenv venvcreates the virtual environment and only has to be executed once.
Install the package
pip install gpiod
To install the Arduino IoT Cloud client library, you only have to do the following:
pip install arduino-iot-cloud swig
Use your favourite programming environment and edit the gpio-basic.py file.
Create a file called credentials.py inside the gpio-basic folder with the following content
DEVICE_ID = b"YOUR_DEVICE_ID"
SECRET_KEY = b"YOUR_SECRET_KEY"
If you are using a different Raspberry Pi flavour or any other machine, you should check which is the right chipset and which are the lines that you want to use. Then, modify the following lines accordingly:
LED=14 # GPIO14, Pin 8
BUTTON=15 # GPIO15, Pin 10
chip = gpiod.Chip('/dev/gpiochip4')
If you want to learn more, check the Annex at the end of this doc.
The dashboard that we are going to build will look like this
There are 2 ways to create the dashboard:
- Create it manually. Replicate the one shown above following the instructions in this guide.
- The LED widgets should be linked to the variable led
- The Value widgets should be linked to the variable test_value
- The Button widgets should be linked to the variable button
- Clone the one provided by this tutorial following the instructions in the Annex
Run your code
(venv)sxxx$ python ./gpio-basic.py
You should see the following:
- Every time push the button, the button widget should be updated
- Every time you change the LED widget in the dashboard, the physical LED should switch to ON or OFF
- The value of
test_valueshould change randomly every 10s and the value updated in the dashboard
Enjoy!
Arduino Cloud is a platform that simplifies the process of developing, deploying, and managing IoT devices. It supports various hardware, including Arduino boards, ESP boards and any device programmed with Python or Javascript. It makes it easy for makers, IoT enthusiasts, and professionals to build connected projects without high programming skills.
The platform allows for easy management and monitoring of connected devices through customizable dashboards, which provide real-time visualisations of the device's data. The dashboards can be accessed remotely through the mobile app Arduino IoT Cloud Remote, which is available for both Android and iOS devices, allowing users to manage their devices from anywhere.
As described in the tutorial, you can create the dashboard on your own, but here I will show you a very handy trick so that you can just make a copy of a template that I have created. For that, you need to use Arduino Cloud CLI.
The steps are the following:
-
Download and extract the latest release. Download it from here Make sure it is in your machine's PATH, so that it can be used globally. After installation, check that it is working by opening a terminal, and type:
-
Set your credentials To authenticate with the Arduino Cloud, we will need to first set our credentials, using our clientId and clientSecret which are obtained from the Arduino Cloud API keys section. Run the following command and introduce the credentials:
arduino-cloud-cli credentials init
- Create the dashboard
arduino-cloud-cli dashboard create \
--name <Your-Dashboard_Name> \
--template rpi-gpio-basic-dashboard.yaml \
--override Raspberry-Basic-GPIO=<Your-Thing-ID>
Replace <Your-Dashboard-Name> and <Your-Thing-ID> with your actual data.
There are many GPIO libraries that can be used with Raspberry Pis. Among some of the most popular, we can find: gpiozero, gpiod, RPi.GPIO. One of the issues that I found is that some of the libraries only work for certain versions of RPI. For instance, the new RPI 5, has a brand new chipset for managing GPIOs, and not all the libraries work for it.
After a lot of googling and searching, I ended up using gpiod as it is the one supported by the Linux kernel team directly and it can be used across all the RPI flavours.
First, you have to install library in the system. If you are using Ubuntu or any other Debian-based machine, you can follow these instructions
sudo apt install gpiod libgpiod-dev libgpiod2 python3-libgpiod
Next, you have to install the PIP package, for that, my recommendation is that you install it in an isolated virtual environment. So, you have to install the following packages
sudo apt install python3-pip python3-virtualenv
To create and activate the virtual environment, use the following code
cd <YOUR_PROJECT_FOLDER>
virtualenv venv
source venv/bin/activate
The GPIOD library has evolved quite a lot in time. The versions before 2.0.0 have a different API than the newer ones. This project is based on the API and syntax of version v2.1.3.
These are the official pages of the Python package:
- https://pypi.org/project/gpiod/
- https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/tree/bindings/python
- https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/about/
If you want to check what is the gpiochip and line that you have to use in the code, you can use the following command line commands.
This is an example of the output in a Raspberry PI 5
$ sudo gpiodetect
gpiochip0 [gpio-brcmstb@107d508500] (32 lines)
gpiochip1 [gpio-brcmstb@107d508520] (4 lines)
gpiochip2 [gpio-brcmstb@107d517c00] (17 lines)
gpiochip3 [gpio-brcmstb@107d517c20] (6 lines)
gpiochip4 [pinctrl-rp1] (54 lines)
$
$ sudo gpioinfo gpiochip4
gpiochip4 - 54 lines:
line 0: "ID_SD" unused input active-high
line 1: "ID_SC" unused input active-high
line 2: "PIN3" unused input active-high
line 3: "PIN5" unused input active-high
line 4: "PIN7" unused input active-high
line 5: "PIN29" unused input active-high
line 6: "PIN31" unused input active-high
line 7: "PIN26" "spi0 CS1" output active-low [used]
line 8: "PIN24" "spi0 CS0" output active-low [used]
line 9: "PIN21" unused input active-high
line 10: "PIN19" unused input active-high
line 11: "PIN23" unused input active-high
line 12: "PIN32" unused input active-high
line 13: "PIN33" unused input active-high
line 14: "PIN8" "rpi-acloud-gpio-basic" output active-high [used]
line 15: "PIN10" unused input active-high
line 16: "PIN36" unused input active-high
line 17: "PIN11" unused input active-high
line 18: "PIN12" unused input active-high
line 19: "PIN35" unused input active-high
line 20: "PIN38" unused input active-high
line 21: "PIN40" unused input active-high
line 22: "PIN15" unused input active-high
line 23: "PIN16" unused input active-high
line 24: "PIN18" unused input active-high
line 25: "PIN22" unused input active-high
line 26: "PIN37" unused input active-high
line 27: "PIN13" unused input active-high
line 28: "PCIE_RP1_WAKE" unused input active-high
line 29: "FAN_TACH" unused input active-high
line 30: "HOST_SDA" unused input active-high
line 31: "HOST_SCL" unused input active-high
line 32: "ETH_RST_N" "phy-reset" output active-low [used]
line 33: "-" unused input active-high
line 34: "CD0_IO0_MICCLK" "cam0_reg" output active-high [used]
line 35: "CD0_IO0_MICDAT0" unused input active-high
line 36: "RP1_PCIE_CLKREQ_N" unused input active-high
line 37: "-" unused input active-high
line 38: "CD0_SDA" unused input active-high
line 39: "CD0_SCL" unused input active-high
line 40: "CD1_SDA" unused input active-high
line 41: "CD1_SCL" unused input active-high
line 42: "USB_VBUS_EN" unused output active-high
line 43: "USB_OC_N" unused input active-high
line 44: "RP1_STAT_LED" "PWR" output active-low [used]
line 45: "FAN_PWM" unused output active-high
line 46: "CD1_IO0_MICCLK" "cam1_reg" output active-high [used]
line 47: "2712_WAKE" unused input active-high
line 48: "CD1_IO1_MICDAT1" unused input active-high
line 49: "EN_MAX_USB_CUR" unused output active-high
line 50: "-" unused input active-high
line 51: "-" unused input active-high
line 52: "-" unused input active-high
line 53: "-" unused input active-high
Check the full documentation of libgpiod and the command line tools here.