Defective INA 226? [SOLVED]

Other Hardware Sensors
1

Hello to all!

I have doubts that my INA 226 is defective...
Voltages are readed fine, but current not working at all, even configuration is not set properly;
I try several INA 226 library and they have similar behavior, no matter internal or external resistor.

Limiting the current from low to high (slowly from 0.100 to 1A ) INA reads 0 or max current ("Max possible current")

I use Arduino-INA226 to verify configs are loaded ok

This is configuration INA code :

ina.configure(INA226_AVERAGES_16, INA226_BUS_CONV_TIME_4156US,INA226_MODE_SHUNT_BUS_CONT);

// Calibrate INA226. Rshunt = 1 ohm, Max excepted current = 4A
ina.calibrate(1.0, 4.0);

Configuration Outoput:

Mode:                  Shunt and Bus, Continuous
Samples average:       16 samples
Bus conversion time:   4.156ms
Shunt conversion time: 4.156ms
Max possible current:  0.08 A
Max current:           0.08 A
Max shunt voltage:     0.08 V
Max power:             2.95 W

Juggling with config to pump up max current to 4A does not make any changes over behavior

2

If I'm reading the datasheet correctly, it says the usable 'Shunt voltage input range' is between –81.9175 and 81.92 mv.

If you are using a 1 ohm resistor and putting 0.1A through it then you will be going over range.
Try a much smaller resistor or smaller current.

3

Using 0.1ohms (original, module resistor) resistor does not make any change...
Onenote, module is it on HIGH side, don't know is there some different configuration for HIGH side.

4

Do post more info about your project. Voltages involved, AC or DC, which exact module used, details on the other shunt resistor used, complete sketch used, and anything else that may or may not be relevant.

5

This is the project I'm flowoing:
uSupply, with this scheme.
I have make little changes over resistors to handle 3A and voltage input type is same as current. And shunt is moved after the power transistor

Arduino sketchs here

About the shut.... it is a japanese one, Non Inductive Resistor MPC** exactly 1ohm (dint remember full name)

INA module

6

mikb55:
http://www.ti.com/lit/ds/symlink/ina226.pdf

If I'm reading the datasheet correctly, it says the usable 'Shunt voltage input range' is between –81.9175 and 81.92 mv.

It seems out of range (need to test more)
I assume i need around 27mΩ shunt.. :confused:

7

Verified!
27mΩ shunt needed to perform 3A current measurements