INA239: VCP Monitor 4 Click using the IC -

Hello Douglas,

You're welcome. Here are my responses to your questions:

1. Our INA239EVM is limited to 10A when you run the current through the PCB, but it has connections for an external shunt resistor so that you can run the current off of the PCB and use whatever current you want. The EVM User's Guide discusses how to do this in section 4.2.3.1.

2. The INA229_239EVM (or in your case, just the INA239EVM) can be connected to whatever MCU you want. It is designed to plug directly into our TI-SCB controller that has a convenient software/GUI package ready to run, but you can always use your own MCU (like the Arduino) instead of our controller. When using your own MCU, you will have to do your own software. However, if you take the software from SysConfig, it can pretty easily be converted into an Arduino project. Here is a guide written by a colleague of mine that shows how to do this (it's written for the INA236, but will apply for the INA239 also. Click the images to enlarge them):

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How to turn SysConfig code into Arduino code:

1. Download all.zip from INA236 ASCStudio Sysconfig
2. Find Arduino documents folder
3. Create new sketchbook folder that is the same name as your main INO file
   1. Create a "main" folder sketchbook to reflect main.ino
4. Change the main.c extension to main.ino
5. Change the sysconfig file extensions from .c & .h to .cpp & .hpp
   1. 
6. Opening main.ino should open the entire sketchbook of files
7. Change the #include statements at the beginning of each file to reflect the extension change (ex. #include "mcu.h" to #include "mcu.hpp")
8. To communicate between your MCU of choice and INA236 (or any other current sensor) you'll need to add MCU-specific code to mcu.cpp. Arduino has a premade library for I2C/two-wire communication called "Wire" - here's a guide
   1. Add an include statement for the Wire library in both mcu.cpp and your main.ino
   2. Start the wire communication in the mcu_i2cInit function
   3. Add write and read code to mcu_i2cTransfer function from examples given in the Wire guide for Arduino
   4. Add delay function to mcu_msWait
      1. This also requires that you add #include <Arduino.h> in your mcu.cpp if you use delay() from the Arduino library
   5. 
9. hpp, INA236.cpp, mcu.hpp, config.cpp, and config.hpp do not require changes beyond the includes and extension changes
10. Finally you'll need to write the main loops inside your main.c now main.ino file
    1. Instead of int main(void) you will have two functions void setup() and void loop() following with standard Arduino
    2. Inside void setup you'll include code to start the wire communication and serial to output the information/current you're reading to the serial monitor in the Arduino IDE. You'll also need to include the configuration function to configure the INA236_0 struct
    3. Inside void loop you will write functions that utilize your INA236.c functions for instance INA236_readReg to pull current values or manufacturing IDs
    4. 
11. From here you can compile the code and upload it to the Arduino
12. To connect the Arduino to an INA236EVM you connect

Regards,

Mitch

Hello Douglas,

Interesting, so maybe there was a problem with the breadboard itself? I'm glad you were able to get the device to work properly with GND connected.

Regards,

Mitch

Hey Douglas,

We do not spec the devices for when there is power but no GND, so it could just be that power is draining somewhere else. I recommend not running the device with power connected and no GND.

Regards,

Mitch