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This version (29 May 2023 09:47) was approved by Michelle Claire So.
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Table of Contents
EVAL-CN0565-ARDZ User Guide
Overview
The EVAL-CN0565-ARDZ is an electrical impedance tomography (EIT) measurement system for characterizing and computing interior impedance of surfaces. The platform allows a conductivity map to be reconstructed using several repeating measurements from electrodes placed at different locations. It supports impedance measurement setups with up to 24 electrodes. The design uses a pair 8×12 analog crosspoint switches, which enables the excitation signal to be applied to one pair of electrodes at a time. The implementation of crosspoint switches allows the circuit to maximize the impedance measurements, which consequently improves the resolution of the constructed images.
The design also features a complete power and signal isolation to the host controller, which can be used as reference for bioimpedance applications.
The board comes in an Arduino-compatible form factor and includes an industry-standard software interface, allowing easy integration to end-user systems as well to connect up to external development platforms such as the EVAL-ADICUP3029.
Simplified Functional Block Diagram
Figure 2. EVAL-CN0565-ARDZ Simplified Block Diagram
Features
- supports 24 impedance input, arbitrarily assignable to quadrupole impedance measurement channels
- supports impedance measurement setups with up to 24 electrode pairs
- accepts measurement frequency range from 0.015 Hz up to 200 kHz
- provides measurement ground that is fully isolated from host computer, with 0.47 uF isolation capacitance
Video
Documents Needed
Equipment Required
Jumper Settings and Configuration
Connectors and Jumpers
- P7 (Chip Select Mapping) - leave this at default for the provided firmware
Figure 3. EVAL-CN0565-ARDZ P7 Pin Location
- P1 (DUT Connections) - shows the pin mapping diagram
Figure 4. EVAL-CN0565-ARDZ P1 Pin Location
System Setup
Hardware Setup
Figure 5. EVAL-CN0565-ARDZ Test Setup
Getting Started
Follow below steps to set up the hardware for testing:
- Check visually if Pins 5 and 6 on the P7 of EVAL-CN0565-ARDZ are shorted by default.
- Connect the EVAL-CN0565-ARDZ (via male header pins) to the EVAL-ADICUP3029 (via female header pins). Ensure that the header pins between the two boards fit properly together.
- Connect the EVAL-ADICUP3029 to the host PC using a micro-USB cable. The DS2 LED in the EVAL-CN565-ARDZ should turn green, this indicates power.
- Upload the CN0565 demo firmware to the EVAL-ADICUP3029 by copying the prebuilt .HEX file directly into the DAPLINK drive.
- Drag and drop the CN0565.HEX file to the DAPLINK. The DAPLINK will automatically disconnect and connect again, this indicates successful uploading.
Ensure that the DAPLINK is visible in the file explorer, this indicates a proper connection between the EVAL-ADICUP3029 and the host PC.
Software Setup
Uploading the HEX File
In order to use the EVAL-CN0565-ARDZ with the EVAL-ADICUP3029, you must upload the CN0565 HEX file. The procedure is as follows:
- Open the file explorer in the Host PC (Windows)
- Open the folder where the CN0565.HEX file is located. If you don't have the HEX file, download this file: CN0565.hex
- Launch another file explorer, and then open the DAPLINK folder.
- Drag and drop the CN0565.HEX file into the DAPLINK folder. The window will automatically close and temporarily disconnect the EVAL-ADICUP3029, and then reconnect again. This is an indication that the HEX file is properly installed.
Installing Software Requirements
- Clone the example firmware from GitHub EVAL-CN0565-ARDZ Python Scripts. This includes the .txt file that contains the required modules and libraries to run the example scripts.
- In Windows, open a command terminal. Point the current working directory to the cloned pyadi-iio repository by changing the directory using this command:
cd C:\GitHub\cn0565\pyadi-iio
- Navigate inside the pyadi-iio folder and install the following requirements using these commands:
pip install -r requirements.txt
pip install -r requirements_dev.txt
pip install -r requirements_doc.txt
pip install -r requirements_prod_test.txt
- To test the source as a standalone module, enter this command:
pip install -e .
- After installing the required modules and libraries, the device is now ready to run example scripts. To run a test script, open the folder where the script is saved and then enter this command:
python file_name.py
Check the active port where the board is connected in your device manager.
Python Example Scripts
Two sample scripts have been created to execute EIT measurements in the EVAL-CN0565-ARDZ. The Specific Electrode Pair script allows the user to measure the impedance on a specific electrode pair, whereas the Electrode Tomography script examines the impedance of the entire test board across all electrodes.
Using the Specific Electrode Pair Script
- Open the command terminal and direct the current working directory to where the example script is saved.
- Run the script by entering this command:
python cn0565_example_single.py -e 0 1 1 0
Prompting these commands in the terminal will give you the Active Port, Frequency and Baud Rate, Electrode Pair, Rectangular and Polar form impedance, and the Real and Imaginary impedance for the specific electrode pair.
The numbers 0, 1, 1, 0 indicate the electrode positions for Force Leads: F+, F-, and Sense Leads: S+, and S-
Using the Electrode Tomography Script
- Open the command terminal and direct the current working directory to the cloned repository.
- Activate the virtual environment by entering this command:
.\env\Scripts\activate
- Change the current directory to where the example script is saved.
- Run the script by entering this command:
python cn0565_example.py
Prompting these commands in the terminal will give you the Electrode Pair, Rectangular and Polar form impedance, and the Real and Imaginary impedance for each electrode pair that is being measured. After measuring all possible electrode pairs, the frequency and the average of the real and imaginary values will display.
After running the sample script, the program will prompt a question whether you like to generate an excel file that contains the measured data.
Enter this command if you want to generate an excel file:
Y
Enter this command if you don't need to generate an excel file:
N
All python scripts used in performing this test are uploaded in the git repository. You may access the repository using this link: EVAL-CN0565-ARDZ Python Scripts
CN0565 GUI Test Example
- Connect the EVAL-CN0565-ARDZ to the EVAL-ADICUP3029 via the Arduino headers.
- Connect to the EVAL-ADICUP3029 to the host PC via a micro-USB cable.
- The DS2 in the EVAL-CN0565-ARDZ must turn green to indicate power.
- Upload the CN0565 demo firmware to the EVAL-ADICUP3029 by copying the prebuilt HEX file directly into the DAPLINK drive (see the ADICUP3029 User Guide).
- Make sure that the DAPLINK is visible in the file explorer, indicating a proper connection between the two boards.
- Drag and drop the CN0565.HEX file to the DAPLINK. The DAPLINK will automatically disconnect and connect again, which indicates successful uploading.
- Open the command prompt in the Host PC (Windows).
- Assuming all requirements have been installed, run the main.py to prompt the CN0565 Realtime EIT GUI.
- Select the type of dataset, type of image reconstruction, number of electrodes, and set the frequency.
- Once all the parameters are set, connect the board to the GUI by selecting Active Comport, and then click Connect. When the board is already connected the image will automatically display.
Disconnecting the board is necessary to run the GUI for another set of measurement. Once disconnected, proceed to Step 6.
Figure 6. Results Displayed in the CN0565 GUI
- Github link for the Python sample script: EVAL-CN0565-ARDZ Python Example
Schematic, PCB Layout, Bill of Materials
EVAL-CN0565-ARDZ Design & Integration Files
- Schematic
- PCB Layout
- Bill of Materials
- Allegro Project
More Information and Useful links
Registration
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End of Document
/srv/wiki.analog.com/data/pages/resources/eval/user-guides/circuits-from-the-lab/cn0565.txt · Last modified: 23 Aug 2023 08:04 by Joyce Velasco