INA219 - Wrong current reading

[r3v1]

The issue

I'm running the example provided by de library with an ESP32 and INA219 sensor, configured for 400mA, 16V and 40mV gain as:

  ESP_ERROR_CHECK(ina219_configure(&dev, INA219_BUS_RANGE_16V, INA219_GAIN_1,
                                   INA219_RES_12BIT_1S, INA219_RES_12BIT_1S, INA219_MODE_CONT_SHUNT_BUS));

That is the same configuration I've been using the Adafruit INA219 library in Arduino. However, the esp-idf-lib library reports wrong measures on this simple circuit (also simulated in Falstad):

The multimeter shows almost the same value around 36mA, but the library says about 76mA.

I think the calibration factor is somehow, in the Arduino library says 0x2000 and here, as is computed dinamically, says 0x1000. I tried to hardcode this value with no positive results. Shunt resistor is set to 100miliohms.

Which SDK are you using?

esp-idf

Which version of SDK are you using?

master

Which build target have you used?

• esp32
• esp32s2
• esp32s3
• esp32c2
• esp8266
• other

Component causing the issue

ina219

Anything in the logs that might be useful for us?

I (102) main_task: Started on CPU0
I (102) main_task: Calling app_main()
I (102) INA219_example: Initializing INA219
D (102) i2cdev: Reconfiguring I2C driver on port 0
D (102) i2cdev: I2C driver successfully reconfigured on port 0
D (112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
D (112) ina219: Initialize, config: 0x03ff
I (112) INA219_example: Configuring INA219
D (112) ina219: Config: 0x019f
D (112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
I (112) INA219_example: Calibrating INA219
D (112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
D (112) ina219: Calibration: 0.1000 Ohm, 0x1000
D (112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
I (102) main_task: Returned from app_main()
I (112) INA219_example: Starting the loop
D (112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
112,92.00
D (1112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
1112,-100.00
D (2112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
2112,76.00
D (3112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
3112,76.00
D (4112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
4112,76.00
D (5112) i2cdev: Timeout: ticks = 0 (0 usec) on port 0
5112,76.00

Additional information or context

No response

Confirmation

• This report is not a question nor a request for drivers.