daqopen-lib

daqopen-lib

This library can be used for various data acquisition tasks to proper handle streaming ADC data for building data acquisition applications.

Documentation incl. tutorials can be found here: docs.daqopen.com

Initially, it is build around the Arduino Due, which has a high-speed ADC with good accuracy and a data transfer via USB 2.0. Most of the examples and driver uses this model together with the firmware which can be found in the firmware folder.

Features

• ADC driver: Driver for communicating with Arduino Due (included firmware) and packing the data to numpy arrays.
• Circular Channel Buffer: A class representing a circular buffer for holding needed amount of data for viewing, calculating and storing.
• DAQ-Info Class: Can be used to exchange informations regarding the interpretation of the data packages. It holds adjustment values and info about the acquisition rate.
• ZMQ-Support: Transfer the acquired data in realtime via zmq to other applications or hosts

Intended Use

This library should be used if:

• you build long-running acquisition applications (e.g. measurement devices)

Installation

Installation from pypi:

pip install daqopen-lib

Install latest directly from Github:

git clone https://github.com/DaqOpen/daqopen-lib.git
cd daqopen-lib
pip install -e .

Usage

SIM (no hardware)

from daqopen.duedaq import DueDaq
import matplotlib.pyplot as plt

# Create Instance of DueDaq
myDaq = DueDaq(serial_port_name="SIM")

# Start acquisition device
myDaq.start_acquisition()

# Read the buffer 10 times
for i in range(10):
    data = myDaq.read_data()

# Hold acqusition device
myDaq.stop_acquisition()

# Plot Data of last buffer
plt.plot(data)
plt.show()

Arduino Due

Setting up Arduino IDE

• Download Arduino IDE for your plattform and start the app
• Install the Package to support SAM-Controllers: Arduino SAM Boards (32-bits ARM Cortex- M3) by Arduino of version 1.6.12

Compiling and Downloading

• Open the sketch-file from firmware/due-daq/due-daq.ino
• Connect the Arduino Due to the "Programming Port" (the port near to the power socket)
• Compile and upload the firmware
• Disconnect from the "Programming Port"

Now, connect the "Native USB Port" (the port near the reset toggle) and use the following sketch for testing the Arduino acquisition:

from daqopen.duedaq import DueDaq
import matplotlib.pyplot as plt

# Create Instance of DueDaq (use empty port name for automatic search)
myDaq = DueDaq()

# Start acquisition device
myDaq.start_acquisition()
for i in range(10):
    data = myDaq.read_data() # read buffer

# Hold acqusition device
myDaq.stop_acquisition()

# Plot Data of last buffer
plt.plot(data)
plt.show()

You should see something like this:

Congratulations!

For more Examples see docs.daqopen.com

Roadmap

A quick and dirty roadmap to show what is planned for the future:

• More practical examples
• Raspberry Pi Pico as DAQ device
• ...

Contributing

I welcome contributions to DaqOpen! If you'd like to contribute, please fork the repository, create a new branch, and submit a pull request.

License

This project is licensed under the MIT License - see the LICENSE file for details.