NAME¶

hwmon_ina219 - Driver for UPS based on INA219

SYNOPSIS¶

hwmon_ina219 -h

hwmon_ina219 -a UPS_NAME [OPTIONS]

The driver implements reading of current and voltage from INA219 by using hwmon sysfs API of the Linux Kernel. There is no other UPS-like logic in there. Based on the measurements of the battery voltage and charging current, the driver makes assumptions of the current state of the system.

SUPPORTED HARDWARE¶

The hwmon_ina219 driver is based on setup with Raspberry PI Compute Module 4 and its baseboard Waveshare CM4-POE-UPS-BASE.

EXTRA ARGUMENTS¶

The required parameter for this driver:

port=hwmon-dir

Optional parameters:

default.battery.charge.low=low-battery-threshold

default.battery.voltage.nominal=voltage-value

default.battery.voltage.low=voltage-value

default.battery.voltage.high=voltage-value

INSTALLATION¶

This driver is specific to the Linux hwmon API.

When using with the Waveshare CM4-POE-UPS-BASE baseboard, there are few steps to be done to enable access to the INA219 circuit:

  dtparam=i2c_vc=on


  dtoverlay=i2c-ina219

/dts-v1/;
/plugin/;
/ {


    compatible = "brcm,bcm2835";


    fragment@0 {


        target = <&i2c_csi_dsi>;


        __overlay__ {


            #address-cells = (1);


            #size-cells = (2);


            ina219@43 {


                status = "okay";


                compatible = "ti,ina219";


                reg = <0x43>;


                shunt-resistor = (3);  // R100


            };


        };


    };
};

$ dtc -@ -I dts -O dtb -o /boot/overlays/i2c-ina219.dtbo i2c-ina219.dts

[ina219]
driver = hwmon_ina219
port = auto

KNOWN ISSUES AND BUGS¶

The driver shutdown function is not implemented.

AUTHORS¶

Andrew Anderson <aander07@gmail.com>

SEE ALSO¶