IoT @ Pickup-Boxes

Set up the development environment

Install the latest Python version

First, download and install the latest version of Python for your operating system (currently 3.10.0).

Download PythonPython.org

Download and install Visual Studio Code

Next, download and install Visual Studio Code, an open-source integrated development environment, for your operating system.

https://code.visualstudio.com/downloadcode.visualstudio.com

Install the Python extension for Visual Studio Code

Visual Studio Code allows you to extend the functionality with so-called extensions. For Python development, I recommend the Python extension. You can install the extension directly from VS Code. Click on the extensions tab on the left menu and type “Python” into the search field. This link takes you to the extensions' website on the VS Code marketplace.

Install Brick Daemon and Brick Viewer

To work with the Tinkerforge devices on your local computer, you need the Brick Daemon to connect to the devices on your USB port. Additionally, to play around with the devices, you can install the Brick Viewer.

Brick Viewer and Daemon

For this project, you don't need to configure the web sockets ports as decribed in the link above.

Set up the Python project

Create a Python virtual environment

When developing in multiple projects with Python, it is a good practice to create a virtual environment for each project. This way you can ensure that you don't have conflicting dependencies between different projects. To create a virtual environment for your project, start a terminal in VS Code and change to the directory where you want the project to be. I put all my code into a directory called c:\code on my main drive:

C:\code\> python -m venv c:\code\tinkerforge-with-python

Activate the virtual environment

Once created, you need to activate the virtual environment as follows:

cd tinkerforge-with-python
C:\code\tinkerforge-with-python> env\Scripts\activate

After this command, the terminal should display this:

(env) C:\code\tinkerforge-with-python>

Install the Tinkerforge library

To work with Tinkerforge devices from our Python code, we need to install their official library:

(env) C:\code\tinkerforge-with-python> pip install tinkerforge

Example 1: Read the humidity sensor once

You can copy the program code below into a new Python file (e.g., run.py). Make sure you replace the UID in line 3 with the correct value for your particular sensor. Run the program by typing python run.py on the terminal.

HOST = "localhost"
PORT = 4223
UID = "Dk8" # Change this value to the UID of your sensor

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_humidity_v2 import BrickletHumidityV2

ipcon = IPConnection() # Create IP connection
h = BrickletHumidityV2(UID, ipcon) # Create device object

ipcon.connect(HOST, PORT) # Connect to brickd
# Don't use device before ipcon is connected

# Get current humidity
humidity = h.get_humidity()
print("Humidity: " + str(humidity/100.0) + " %RH")

input("Press key to exit\n") # Use raw_input() in Python 2
ipcon.disconnect()

If everything works correctly, the terminal should display the current humidity:

The output of the example program above.

Example 2: Read the humidity sensor continuously

For most use cases, it makes sense to read the values continuously. Either in a certain time interval (e.g, every second), or whenever the value changes. The following example uses a so-called callback function callback_humidity that is registered with the sensor (line 20) and called every 1000 milliseconds (line 23).

HOST = "localhost"
PORT = 4223
UID = "Dk8" # Change this value to the UID of your sensor

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_humidity_v2 import BrickletHumidityV2

# Callback function for humidity callback
def callback_humidity(humidity):
    print("Humidity: " + str(humidity/100.0) + " %RH")


ipcon = IPConnection() # Create IP connection
h = BrickletHumidityV2(UID, ipcon) # Create device object

ipcon.connect(HOST, PORT) # Connect to brickd
# Don't use device before ipcon is connected

# Register humidity callback to function cb_humidity
h.register_callback(h.CALLBACK_HUMIDITY, callback_humidity)

# Set period for humidity callback to 1s (1000ms) without a threshold
h.set_humidity_callback_configuration(1000, False, "x", 0, 0)

input("Press key to exit\n") # Use raw_input() in Python 2
ipcon.disconnect()

The result is a continuous output of the humidity value (every 1 second) until the user interrupts the program with ⌨ Ctrl + X.

The output of the example program above.

You can find this example and the API documentation for all devices on the official Tinkerforge website:

Doc | Tinkerforge