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This version (03 Aug 2017 17:37) was approved by rgetz.

CO Toxic Gas Measurement Demo (with EVAL-CN0357-ARDZ)

The cn0357_example_noos is a toxic gas(CO) detector demo project for the EVAL-ADICUP3029 base board with additional EVAL-CN0357-ARDZ shield, created using the CrossCore Embedded Studio environment.

General Description/Overview

This user guide gives a detailed explanation about cn0357_example_noos toxic gas (CO) detection project for EVAL-ADICUP3029 base board and EVAL-CN0357-ARDZ gas sensor shield. The gas sensor shield consists of portable gas detector circuit.

The EVAL-CN0357-ARDZ shield circuit provides a potentiostatic circuit for biasing the electrochemical sensor and 16-bit Sigma-Delta ADC. The small currents passing in the sensor is being converted to a voltage that can be read by the ADC. The 16-bit ADC value is received via SPI interface of the EVAL-ADICUP3029 board, where the gas concentration is computed.

The cn0357_example_noos application configures the necessary components, processes ADC output value and make all necessary conversions in order to provide the gas concentration. A UART interface (38400 baud rate and 8-bits data length) is used to send the results to terminal window: CO Concentration in Parts Per Million(PPM) are the outputs provided in the terminal window.

At the start of the project, the software computes the necessary parameters and configure the digital rheostat(AD5270) . The required parameters are the sensor sensitivity and feedback resistor range. These can be modified by changing the values of the constants CN0357_SENSOR_SENSITIVITY and CN0357_FEEDBACK_RESISTOR found in the adi_cn0357.h header file of the project.

Demo Requirements

The following is a list of items needed in order to replicate this demo.

  • Hardware
    • EVAL-ADICUP3029
    • EVAL-CN0357-ARDZ
    • Mirco USB to USB cable
    • PC or Laptop with a USB port
    • 7V - 12V DC power supply (only if you have Rev B of the CN0357)
  • Software
    • cn0357_example_noos software
      • Inside Sensor_Sw Pack (1.0.0 or higher)
    • CrossCore Embedded Studio (2.6.0 or higher)
    • ADuCM302x DFP (2.0.0 or higher)
    • ADICUP3029 BSP (1.0.0 or higher)
    • Android IoTNode App (optional)
      • Either Android or iOS version
    • Serial Terminal Program (Required for running in release mode only)
      • Such as Putty or Tera Term

Setting up the hardware

  1. Make sure that Carbon Monoxide sensor CO-AX is properly placed on the EVAL-CN0357-ARDZ sensor shield ()
  2. Ensure the jumper AD5720_CS has a shunt across Pin 3 and Pin 4 of the EVAL-CN0357-ARDZ
  3. Ensure the jumper AD7790_CS has a shunt across Pin 1 and Pin 2 of the EVAL-CN0357-ARDZ
  4. Place the (S5) switch position to read “Wall/USB”, and the (S2) switch position to read “USB” on the EVAL-ADICUP3029.
  5. Mount EVAL-CN0357-ARDZ on the EVAL-ADICUP3029 base board such that DIGI1 and DIGI0 of the EVAL-CN0357-ARDZ are connected to the P6 and P7 on the EVAL-ADICUP3029 board respectively.
  6. Plug in the micro USB cable into the (P10) USB port on the EVAL-ADICUP3029, and the other end into the PC or laptop.

Extremely important to plug in an acceptable power supply to the barrel jack P2 of the EVAL-ADICUP3029 to supply power for the EVAL-CN0357-ARDZ Rev B. The boards will not work if you try only to power it from the USB. The external power supply is not required for EVAL-CN0357-ARDZ Rev C.


Configuring the Software

The CN0357 comes with a carbon monoxide sensor, and those default settings are programmed into the software. If you decide to use a different type of sensor, you will need to change the sensor sensitivity and feedback resistor.

In adi_cn0357.h header file the user can configure parameters:

  • CN0357_FEEDBACK_RESISTOR - CN0357_FEEDBACK_RESISTOR -This is the value that the rheostat needs to be configured to for proper operation (ohms). This value is dervied from equation 2 (located on page 2) on the CN0357 datasheet.
    #define CN0357_FEEDBACK_RESISTOR (9230.76)
  • CN0357_SENSOR_SENSITIVTY - CN0357_SENSOR_SENSITIVTY - sensitivity (nA/ppm) of the electrochemical sensor being used.
    #define CN0357_SENSOR_SENSITIVTY (0.0000000065)   


In the cn0357_app.h header files you can configure the following parameters:

  • ADI_APP_DISPATCH_TIMEOUT - DISPATCH TIMEOUT will define how often the data is sent over Bluetooth.
  • ADI_APP_USE_BLUETOOTH - ENABLE BLUETOOTH parameter - will either use Bluetooth or will have the option to print to console window in debug mode or terminal in release mode.


Obtaining the source code

We recommend not opening the project directly, but rather import it into CrossCore Embedded Studio and make a local copy in your workspace.

The source code and include files of the cn0357_example_noos can be found below:


Outputting Data

Once the hardware is setup and software is configured, user needs to select how they want to view the data coming from the gas sensor(CN0357).

There are three different ways to visualize the data:

  • CrossCore Embedded Studio Console Window (through semihosting)
  • Serial Terminal Program (such as Putty or Tera Term)
  • IoTNode Smart Device App

Depending on how you want to operate the board and visualize the data, there are two different options that must be selected from. Below is a table outlining the general operation, and you need to click on which launch file you need to program onto the EVAL-ADICUP3029, and hit the <F5> key on your keyboard.

Data Output Destination Connected to Debugger Configuration File
CCES Console Window Yes ADICUP3029_Debug.launch
PC/Laptop Serial Terminal No ADICUP3029_Release.launch
IoTNode Smart App Yes ADICUP3029_Debug.launch
IoTNode Smart App No ADICUP3029_Release.launch



The data for this demo can be viewed in the serial terminal window (via UART) and by connecting to the Analog Devices iOS Smart Device App (for more information and installation directions check out the iOS Smart Device App page) or Android Smart Device App (for more information and installation directions check out the Android Smart Device App page)

Debug Launch Mode

Debug launch mode is used when connected to the debugger. In debug mode, all the outputs are directed to the console window of the CrossCore tools via semihosting. The data is also sent by default to the IoTNode smart app (ADI_APP_USE_BLUETOOTH =1), but can be turned of if desired by setting ADI_APP_USE_BLUETOOTH = 0.

Figure shows when ADI_APP_USE_BLUETOOTH is set to 1, sensor data is sent to the smart app and printed onto the console.

If you have the app installed on your phone, these figure shows the output on android device.

Do not try to connect directly (or pair) to the EVAL-ADICUP3029 from your phone.

  1. Simply open up the IoTNode application on your phone.
  2. “Scan” for nearby demos.
  3. Once you find your demo, click on it to open it up.
  1. Android App display
  2. iOS App display



Release Launch Mode

Release launch mode is used for running without the debugger connected. When in release mode, console output is redirected to UART. Bluetooth is enabled, and sensor data is sent to android application. If disabled, sensor data is directed only to the UART. If you are using the UART to make print to the PC/laptop, here are the settings your TCP client must be set too. Following is the UART configuration.

  Select COM Port
  Baud rate: 38400
  Data: 8 bit
  Parity: none
  Stop: 1 bit
  Flow Control: none


Figure shows the UART terminal when ADI_APP_USE_BLUETOOTH is set to 1

iOS App and Android App display If you have the app installed on your phone, these figure shows the output on android device.

Do not try to connect directly (or pair) to the EVAL-ADICUP3029 from your phone.

  1. Simply open up the IoTNode application on your phone.
  2. “Scan” for nearby demos.
  3. Once you find your demo, click on it to open it up.
  1. Android App display
  2. iOS App display



How to use the Tools

The official tool we promote for use with the EVAL-ADICUP3029 is CrossCore Embedded Studio. For more information on downloading the tools and a quick start guide on how to use the tool basics, please check out the Tools Overview page.

Importing

For more detailed instructions on importing this application/demo example into the CrossCore Embedded Studios tools, please view our How to import existing projects into your workspace section.

Debugging

A debug configuration must be set up for this project in order to have the possibility to program and to debug the ADICUP3029_CN0357 project. To do this, follow the instructions from How to configure the debug session section.

  • Make sure the target board is connected to workstation (via USB at P10) and using the tool bar, navigate to the small Debug icon and select the debugging session you created. The application will programmed and the program execution will stop at the beginning of the main() function.
  • Use step-by-step execution or directly run the program.

After completion of the steps above the program will be loaded onto the system FLASH and it will run by default every time the board is powered up.


Project Structure

The cn0357_example_noos project use ADuCM302x C/C++ Project structure.

This project contains: system initialization part - disabling watchdog, enabling clock for peripherals; port configuration for SPI0;SPI2;UART , SPI and UART initialisation, SPI, UART read/write functions, AD7790 control, AD5270 control and gas concentration computation, BLE initialization, packet formation and sending data .

The cn0357_app.cpp is the application file for the project. The ADuCM3029 folder consists of pinmux for SPI0, SPI2 and UART0.

The RTE folder contains ADuCM3029 Device Family Pack,Board Support Package files and Sensor Config files related to cn0357_example_noos project.



End of Document

resources/eval/user-guides/eval-adicup3029/reference_designs/demo_cn0357.txt · Last modified: 31 Jul 2017 19:40 by Brandon