This High Current INA3221 Version has Shunt Resistors of 0.02 Ohms versus 0.1 Ohm for the normal INA3221 Boards.
This product is identical to the INA3221 Breakout Board except for the addition of screw terminals for the IN1-, IN1+, IN2-, IN2+, IN3-,IN3+ pin header terminals.
To use this INA3221 properly scaled, you will need to change this value in SDL_Arduino_INA3221.h to:
#define SHUNT_RESISTOR_VALUE (0.02) // default shunt resistor value of 0.1 Ohm / 0.02 ohm for high current
In the Raspberry Pi Drivers, change:
SHUNT_RESISTOR_VALUE = (0.1) # default shunt resistor value of 0.1 Ohm
SHUNT_RESISTOR_VALUE = (0.02) # default shunt resistor value of 0.1 Ohm
The INA3221 Breakout Board is a three-channel, high-side current and bus voltage monitor with an I2C interface and Grove Connectors/Pin Headers and screw terminals. Sometimes, you want to measure lots of things in your system. A great example is when you have a solar powered system. To figure out what is going on in your solar system dynamically, you need to measure the current and voltage for the Solar Cells, Batteries and the Load (computer) all at the same time. The conventional way to do this is to use three s INA219 (same function, but only one channel) for a higher cost and much more wiring / space. This INA3221 breakout board will do the same job as three INA219's but for about half the cost and about 50% of the space.
You can use it both with a Grove I2C Connector and standard pin headers. Sometimes, you want to measure lots of things in your system. A great example is when you have a solar powered system. To figure out what is going on in your solar system dynamically, you need to measure the current and voltage for the Solar Cells, Batteries and the Load (computer) all at the same time. The conventional way to do this is to use three $10 INA219 (same function, but only one channel) for a cost of $30 and much more wiring / space. The INA3221 Breakout Board Replaces 3 INA219 Boards.
- The full specification for the Dual Grove/Pin Header INA3221 Breakout Board is available here (updated on March 26, 2016)
- The Version 1 specification for the INA3221 Breakout Board (without the Grove Connector) is available here.
- Arduino SunAirPlus INA3221 Current Measuring Drivers
- Raspberry Pi Python SunAirPlus INA3221 Current Measuring Drivers
- ESP8266 SunAirPlus INA3221 Library
- node + mraa library for reading from SwitchDoc Labs SunAirPlus or INA3221 Breakout Board
What are Grove Connectors?
Check out this Grove Connector tutorial.
How to Use
To use the INA3221, you connect the I2C bus up to an Arduino or Raspberry Pi (using the Grove connector or the Pin headers) and then connect the loads that you want to measure as shown in the block diagram below. See the wiring lists for the Arduino and Raspberry Pi in the specification above.
SwitchDoc Labs developed this pure Python INA3221 Raspberry Pi library as part of the SunAirPlus product development and for this INA3221 Breakout Board. Here are several articles about these drivers: Raspberry Pi and Arduino Power Consumption - INA3221 INA3221 Arduino Library Released INA3221 Python Raspberry Pi Library Released It is similar to using three INA219 High Side Current Monitors, but not quite. There are significant differences in the chip itself and especially in the software needed. In SunAirPlus, we want to measure the current and voltage for all three major subsystems: The LiPo Battery, Solar Panels and the Computer. The software is located on the SwitchDoc Labs github under https://github.com/switchdoclabs/SDL_Pi_INA3221. Arduino drivers are also located on github under https://github.com/switchdoclabs/SDL_Arduino_INA3221. The first test on the Raspberry Pi should always be “i2cdetect -y 1” which should show you the INA3221 at the default address of 0x40. A similar test can be run on the Arduino. Running the test results from the INA3221 Breakout board are below:
Test SDL_Pi_INA3221 Version 1.0 - SwitchDoc Labs
Sample uses 0x40 address and SunAirPlus board INA3221
Will work with the INA3221 SwitchDoc Labs Breakout Board
------------------------------ LIPO_Battery Bus Voltage: 4.15 V LIPO_Battery Shunt Voltage: -9.12 mV LIPO_Battery Load Voltage: 4.14 V LIPO_Battery Current 1: 91.20 mA Solar Cell Bus Voltage 2: 5.19 V Solar Cell Shunt Voltage 2: -73.52 mV Solar Cell Load Voltage 2: 5.12 V Solar Cell Current 2: 735.20 mA Output Bus Voltage 3: 4.88 V Output Shunt Voltage 3: 48.68 mV Output Load Voltage 3: 4.93 V Output Current 3: 486.80 mA