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Python

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README

This PASCO Python library allows users to connect to PASCO Wireless sensors using Python. Create your own data collection application, use sensors to interact with other hardware devices, or come up with your own unique solution!

For project examples, view our pasco_python_examples repository.

Contents:

How do I get started?

First, make sure you are working with Python 3.11 (see Troubleshooting for Python version help)

To install the PASCO package into your Python environment, type this into your Terminal

pip install pasco

In your project file, import the PASCOBLEDevice class, the CodeNodeDevice class, and/or the ControlNodeDevice class.

Compatible Sensors

Connecting to a sensor

Device Structure

Device: A physical PASCO wireless sensor is a device.

Sensor: A device can have multiple sensors built in.

Measurements: A sensor can offer multiple measurements.

Device Structure Example

A Wireless Weather Sensor would be a "device". The "device" has 4 sensors ['WirelessWeatherSensor', 'WirelessGPSSensor', 'WirelessLightSensor', 'WirelessCompass']

Each "sensor" can have multiple measurements

Available Commands

device = PASCOBLEDevice() Create a Bluetooth device object
device.scan(sensor_name_filter: string [optional]) Scan for available bluetooth devices. Returns a list of available devices
device.connect(ble_device: BLEDevice) Connect to a device using the object returned from the scan command.
device.connect_by_id(pasco_device_id: string) Connect to a device using the 6 digit ID printed on the sensor.
device.disconnect() Disconnect from a device
device.is_connected() Returns true/false to tell device connection state
device.get_sensor_list() Get a list of sensors that a device has
device.get_measurement_list(sensor_name: string [optional]) Returns all the measurements that a device has
device.read_data(measurement: string) Get a single reading from a single measurement
device.read_data_list(measurements: List[string]) Get a list of readings for multiple measurements
device.get_measurement_unit(measurement: string) Get the default units for a single measurement
device.get_measurement_unit_list(measurements: List[string]) Get a list of default units for multiple measurements

Step 1: Import the appropriate module

For a regular wireless sensor:

from src.pasco.pasco_ble_device import PASCOBLEDevice 
# src is necessary until pip repository is updated

To connect to a /\/code.Node (Note: The Icons package is optional):

from src.pasco.code_node_device import CodeNodeDevice, Icons

To connect to a /\/control.Node:

from src.pasco.control_node_device import ControlNodeDevice

Step 2: Create an object for the device

my_sensor = PASCOBLEDevice()

If you know the device's 6-digit serial ID (printed on the device) you can quickly scan and connect using the command: my_sensor.connect_by_id('111-123')

Otherwise perform Steps 2 & 3 to scan/connect.

Step 3: Scan for available bluetooth (BLE) sensors

my_sensor.scan() Returns list of BLE devices found in the scan. my_sensor.scan('Temperature') Returns a list of Temperature sensors found

How to use:

found_devices = my_sensor.scan()

Step 4: Connect to a BLE sensor found from the scan

The scan command will return a list of found devices. Iterate through that list to determine which device you want to connect to.

One way is to print the list and prompt the user like this:

if found_devices:
    print('\nDevices Found')
    for i, ble_device in enumerate(found_devices):
        print(f'{i}: {ble_device.name}')

    selected_device = input('Select a device: ') if len(found_devices) > 1 else 0
    code_node_device.connect(found_devices[int(selected_device)])
else:
    print("No Devices Found")
    exit(1)

Putting it all together:

from src.pasco.pasco_ble_device import PASCOBLEDevice

my_sensor = PASCOBLEDevice()
found_devices = my_sensor.scan()

if found_devices:
    print('\nDevices Found')
    for i, ble_device in enumerate(found_devices):
        print(f'{i}: {ble_device.name}')

    selected_device = input('Select a device: ') if len(found_devices) > 1 else 0
    my_sensor.connect(found_devices[int(selected_device)])
else:
    print("No Devices Found")
    exit(1)

print(f"measurements: {my_sensor.get_measurement_list()}")
my_sensor.disconnect()

Step 5: View Device Sensor(s)

A device can have one or more on-board sensors. To view the list of sensors use the command my_sensor.get_sensor_list(). This returns a list of sensor names that a device has.

Step 6: View Device Measurement(s)

Each sensor in the device can have one or more measurements. If you want to view all the measurements that a device has, use the command my_sensor.get_measurement_list().

To view only the measurements that a sensor has, use the sensor name (from the list in Step 4) like this my_sensor.get_measurement_list('WirelessWeatherSensor').

Step 7: Start collecting data!

The measurement variable names come from Step 4

To read the Temperature my_temperature_sensor.read_data('Temperature')

To read the RelativeHumidity my_weather_sensor.read_data('RelativeHumidity')

To read a multiple measurements at one time my_weather_sensor.read_data_list(['Temperature','RelativeHumidity'])

To get the units for a single measurement my_temperature_sensor.get_measurement_unit('Temperature')

To get the units for a list of measurements my_weather_sensor.get_measurement_unit_list(['Temperature','RelativeHumidity'])

Let's put it all together

Example: One shot read

from src.pasco.pasco_ble_device import PASCOBLEDevice

temp_sensor = PASCOBLEDevice()
temp_sensor.connect_by_id('055-808') # replace with your sensor's 6-digit id

temp_value = temp_sensor.read_data('Temperature')
temp_units = temp_sensor.get_measurement_unit('Temperature')
print(f'{temp_value} {temp_units}')

temp_sensor.disconnect()

Example: Scan/select a sensor and read data

Scan for a sensor and get the current temperature. In this example we can use a Temperature, Weather or /\/code.Node to read the temperature measurement. We do not need to specify a device type. We will continuously read and display the result.

from src.pasco.pasco_ble_device import PASCOBLEDevice

my_sensor = PASCOBLEDevice()
found_devices = my_sensor.scan()

if found_devices:
    print('\nDevices Found')   
    for i, ble_device in enumerate(found_devices):
        print(f'{i}: {ble_device.name}')

    selected_device = input('Select a device: ') if len(found_devices) > 1 else 0
    my_sensor.connect(found_devices[int(selected_device)])
else:
    print("No Devices Found")
    exit(1)

# Loop that will read/display the data 100 times
for i in range(100):
    current_temp = my_sensor.read_data('Temperature')
    print(f'The current temp is {current_temp}')

my_sensor.disconnect()

/\/code.Node

In order to connect to a /\/code.Node we must import the CodeNodeDevice object and (optionally) the character library which allows a user to display icons on the 5x5 LED Array.

from src.pasco.code_node_device import CodeNodeDevice, Icons

my_code_node = CodeNodeDevice() Create /\/code.Node Bluetooth device object
my_code_node.set_led_in_array() Set an individual LED in the 5x5 LED Array
my_code_node.set_leds_in_array() Set multiple LEDs in the 5x5 LED Array
my_code_node.set_rgb_led() Set the RGB LED
my_code_node.set_sound_frequency() Set the speaker frequency
my_code_node.scroll_text_in_array Scroll text on the 5x5 LED Array
my_code_node.show_image_in_array() Display an image in the 5x5 LED Array
my_code_node.reset() Reset all of the /\/code.Node outputs

Set LEDs on the 5x5 Display

x, y coordinates on the //code.Node 5x5 LED display
---------------------------
| 0,0  1,0  2,0  3,0  4,0 |
| 0,1  1,1  2,1  3,1  4,1 |
| 0,2  1,2  2,2  3,2  4,2 |
| 0,3  1,3  2,3  3,3  4,3 |
| 0,4  1,4  2,4  3,4  4,4 |
---------------------------

intensity range is 0-255

Set one LED

code_node_device.set_led_in_array(x, y, intensity)

Example: This will turn the top center LED on at max brightness

code_node_device.set_led_in_array(2, 0, 255)

Set multiple LEDs at once

code_node_device.set_leds_in_array(led_list, intensity)

led_list = [[4,4], [0,4], [2,2]]
code_node_device.set_leds_in_array(led_list, 128)

Set the RGB LED

code_node_device.set_rgb_led(r, g, b) r, g, b indicate brightness ranges between 0 and 255.

r = 20
g = 100
b = 200
code_node_device.set_rgb_led(r, g, b)

Turn the speaker on/off

code_node_device.set_sound_frequency(frequency) Send frequency (int) in Hz

code_node_device.set_sound_frequency(440)

Turn the speaker off

code_node_device.set_sound_frequency(0)

Scroll Text on the 5x5 LED Array

code_node_device.scroll_text_in_array(text) This will scroll the text on the /\/code.Node's display

code_node_device.scroll_text_in_array('HELLO WORLD')

The character library

code_node_device.show_image_in_array(Icons().smile) If we import the Icons class from the character_library to our project we can show unique images on the 5x5 LED Array. Refer to the library file to see available options. Examples:

code_node_device.show_image_in_array(Icons().smile)
code_node_device.show_image_in_array(Icons().heart)

Reset the code_node outputs

code_node_device.reset() Turn the 5x5 LED display, RGB LED and speaker off.

Example: Working with the /\/code.Node

Below is a simple example that shows how to connect to a /\/code.Node, read a measurement and control an output.

from src.pasco.code_node_device import CodeNodeDevice

code_node = CodeNodeDevice()
code_node.connect_by_id('481-782') # replace with your device's 6-digit id

while code_node.read_data('Button1') == 0:
    if code_node.read_data('Brightness') < 2:
        code_node.set_rgb_led(100,100,100)
    else:
        code_node.set_rgb_led(0,0,0)

code_node.scroll_text_in_array('Goodbye')

code_node.reset()
code_node.disconnect()

Example: Connect to multiple sensors

We can also connect to multiple sensors. Here we are connecting to a /\/code.Node and Wireless Force Sensor. We are also using /\/code.Node specific commands and testing the Character Library.

from src.pasco.pasco_ble_device import PASCOBLEDevice
from src.pasco.code_node_device import CodeNodeDevice, Icons

code_node_device = CodeNodeDevice()
found_devices = code_node_device.scan('//code.Node')

if found_devices:
    for i, ble_device in enumerate(found_devices):
        print(f'{i}: {ble_device.name}')

    selected_device = input('Select a device: ') if len(found_devices) > 1 else 0
    code_node_device.connect(found_devices[int(selected_device)])
else:
    print("No Devices Found")
    exit(1)

force_accel_device = PASCOBLEDevice()
found_devices = force_accel_device.scan('Force')

if found_devices:
    for i, ble_device in enumerate(found_devices):
        print(f'{i}: {ble_device.name}')

    selected_device = input('Select a device: ') if len(found_devices) > 1 else 0
    force_accel_device.connect(found_devices[int(selected_device)])
else:
    print("No Devices Found")
    exit(1)

code_node_device.reset()
light_on = False

for i in range (1000):
    if force_accel_device.read_data('Force') > 10:
        if light_on == False:
            code_node_device.set_rgb_led(100,100,100)
            code_node_device.set_sound_frequency(200)
            code_node_device.show_image_in_array(Icons().alien)
            light_on = True
        else:
            code_node_device.reset()
            light_on = False
        while force_accel_device.read_data('Force') > 10:
            pass

code_node_device.disconnect()
force_accel_device.disconnect()

/\/control.Node

The control node has an internal speaker and x,y,z acceleration sensor. But what makes the control node unique is that it can also connect to external devices such as a rangefinder, steppers, and servos. Any sensor plugged into the control node is automatically accessible just like a built-in sensor.

The control.Node has commands for setting steppers, servos, and the power output board as well as sensing from steppers, servos, and plugin sensors.

If you know the 6-digit code of your control node device, you can just connect:

from src.pasco.control_node_device import ControlNodeDevice
import time

controlNode = ControlNodeDevice()
controlNode.connect_by_id('664-591') # replace with your device's 6-digit id

Now put the \/\/control.Node into the pascobot. Plug in the steppers into ports A and B on the \/\/control.Node, and run the following code. 

from src.pasco.control_node_device import ControlNodeDevice
import time

controlNode = ControlNodeDevice()
controlNode.connect_by_id('664-591') # replace with your device's 6-digit id

controlNode.rotate_steppers_continuously(360, 360, 360, 360)
time.sleep(1)
controlNode.stop_steppers(360, 360)
print(controlNode.read_data('Angle', 'A'))
controlNode.disconnect()

This accelerates both steppers to 360 deg/s at an acceleration of 360 deg/s/s, waits a second, stops them at an acceleration of 360 deg/s/s, and reads the angle of stepper A. More examples of steppers, servos, plugin sensors, and the power output board are in controlnode_examples.py and grabberbot.py.

Troubleshooting

1. Are you working with Python 3.11?

To check your version type in your terminal

python --version

If that doesn't work try 

python3 --version

If that doesn't work you don't have python installed. Go to https://www.python.org/ and install.

If you have an older version of python installed, uninstall it and reinstall 3.11. After you reinstall Python you will also need to reinstall the pasco package.

2. Is pasco installed?

If you get an error like no module named "<module name>" try

pip install pasco

3. Is the device on?

Check if the red light is blinking. If so you're good to go.

4. Is the device already connected?

Check if the light is green. If so, hold down the power button to turn the device off, and press it to turn the device on again. When the light blinks red you're good.

5. Fire the intern.