Current overflow false positive

[chrisb2]

Current overflow false positive

[Gbassous]

To get it working for now, i set __OVF = 0, since I am well aware of the tension and current values I am working with. I believe that somewhere in the current overflow detection procedure the comparison is being made against max tension instead of max current.

[chrisb2]

Could you provide some more details? Most usefully an example of the code which calls the library and example of the behavior with logging enabled?

If you know in advance your current/voltage then the option described in Advanced - Manual Gain, High Resolution is probably best, is this what you are using?

regards,
Chris

[Gbassous]

This is what i get with logging and both auto-gain and manual gain:
2019-02-05 15:15:46,955 - INFO - INA219 gain set to 0.32V
2019-02-05 15:15:46,956 - INFO - INA219 calibrate called with: bus max volts: 32V, max shunt volts: 0.32V, max expected amps: 1.600A
2019-02-05 15:15:46,956 - INFO - INA219 max possible current: 3.200A
2019-02-05 15:15:46,957 - INFO - INA219 max expected current: 1.600A
2019-02-05 15:15:46,957 - INFO - INA219 current LSB: 4.878e-05 A/bit
2019-02-05 15:15:46,957 - INFO - INA219 power LSB: 9.756e-04 W/bit
2019-02-05 15:15:46,957 - INFO - INA219 max current before overflow: 1.5984A
2019-02-05 15:15:46,958 - INFO - INA219 max shunt voltage before overflow: 159.8390mV
2019-02-05 15:15:46,958 - INFO - INA219 calibration: 0x20cc (8396)
press s for sample, e to save and end, k to end without saving: s
2019-02-05 15:15:47,893 - INFO - INA219 Current overflow detected - attempting to increase gain
2019-02-05 15:15:47,896 - INFO - INA219 gain is currently: 0.32V
2019-02-05 15:15:47,897 - INFO - INA219 Device limit reach, gain cannot be increased
Traceback (most recent call last):
File "power_calib.py", line 18, in
sample = numpy.array([ina.voltage(),ina.shunt_voltage()])
File "/home/pi/.virtualenvs/py3cv4gpio_mestrado/lib/python3.5/site-packages/ina219.py", line 194, in shunt_voltage
self._handle_current_overflow()
File "/home/pi/.virtualenvs/py3cv4gpio_mestrado/lib/python3.5/site-packages/ina219.py", line 221, in _handle_current_overflow
self._increase_gain()
File "/home/pi/.virtualenvs/py3cv4gpio_mestrado/lib/python3.5/site-packages/ina219.py", line 246, in _increase_gain
raise DeviceRangeError(self.__GAIN_VOLTS[gain], True)
ina219.DeviceRangeError: Current out of range (overflow), for gain 0.32V, device limit reached

I'm running 2 V / 0.36 A through my circuit (according to the power supply indicators), with a 5 Ohm load. With a voltmeter I get 0.038 V in the shunt. If I run a current lower than 0.32 A it works without a problem. By setting __OVF = 0, from what I understood from your code, it doesn't flag any overflows and I am able to measure currents over 0.32 A with manual gain. What I find oddly coincidental (which means it probably isn't) is that it's detecting overflow when the current is at the value for max voltage in the shunt.

Regards,
Guilherme

[chrisb2]

This does seem puzzling. I did some testing on my system with the following test program, which I think has the same configuration parameters that you using (at least log output is identical):

#!/usr/bin/env python
from ina219 import INA219
from ina219 import DeviceRangeError
import logging

SHUNT_OHMS = 0.1


def read():
    ina = INA219(SHUNT_OHMS, 1.6, log_level=logging.INFO)
    ina.configure(ina.RANGE_32V, ina.GAIN_8_320MV)

    print("Bus Voltage: %.3f V" % ina.voltage())
    try:
        print("Bus Current: %.3f mA" % ina.current())
        print("Power: %.3f mW" % ina.power())
        print("Shunt voltage: %.3f mV" % ina.shunt_voltage())
    except DeviceRangeError as e:
        # Current out of device range with specified shunt resister
        print(e)


if __name__ == "__main__":
    read()

My test load is a little different (its a 12V/21W car bulb) which results in my being able to generate the same current as you, but at a higher voltage. The higher voltage should not make a difference.

With the current just under the limit indicated in the logging (1.594A), I got:

2019-02-06 12:00:57,719 - INFO - INA219 gain set to 0.32V
2019-02-06 12:00:57,723 - INFO - INA219 calibrate called with: bus max volts: 32V, max shunt volts: 0.32V, max expected amps: 1.600A
2019-02-06 12:00:57,726 - INFO - INA219 max possible current: 3.200A
2019-02-06 12:00:57,730 - INFO - INA219 max expected current: 1.600A
2019-02-06 12:00:57,739 - INFO - INA219 current LSB: 4.878e-05 A/bit
2019-02-06 12:00:57,743 - INFO - INA219 power LSB: 9.756e-04 W/bit
2019-02-06 12:00:57,759 - INFO - INA219 max current before overflow: 1.5984A
2019-02-06 12:00:57,762 - INFO - INA219 max shunt voltage before overflow: 159.8390mV
2019-02-06 12:00:57,765 - INFO - INA219 calibration: 0x20cc (8396)
Bus Voltage: 10.884 V
Bus Current: 1584.537 mA
Power: 17252.683 mW
Shunt voltage: 158.490 mV

and with the current just over the limit:

2019-02-06 12:01:27,908 - INFO - INA219 gain set to 0.32V
2019-02-06 12:01:27,912 - INFO - INA219 calibrate called with: bus max volts: 32V, max shunt volts: 0.32V, max expected amps: 1.600A
2019-02-06 12:01:27,916 - INFO - INA219 max possible current: 3.200A
2019-02-06 12:01:27,919 - INFO - INA219 max expected current: 1.600A
2019-02-06 12:01:27,929 - INFO - INA219 current LSB: 4.878e-05 A/bit
2019-02-06 12:01:27,932 - INFO - INA219 power LSB: 9.756e-04 W/bit
2019-02-06 12:01:27,941 - INFO - INA219 max current before overflow: 1.5984A
2019-02-06 12:01:27,949 - INFO - INA219 max shunt voltage before overflow: 159.8390mV
2019-02-06 12:01:27,952 - INFO - INA219 calibration: 0x20cc (8396)
Bus Voltage: 11.540 V
Current out of range (overflow), for gain 0.32V

So my system is not replicating the issue you have. Can you draw and attach the circuit diagram for your setup?

regards,
Chris

[chrisb2]

I attached my test circuit:

[chrisb2]

Closing this issue, please re-open if you require further assistance.

[wojciechczyz]

I have got exactly the same problem when trying to install Raspberry PI i52 UPS Plus HAT. Device is called EP-0136
https://wiki.52pi.com/index.php/UPS_Plus_SKU:_EP-0136

I am getting following error:

---

------Current information of the detected Raspberry Pi------

Raspberry Pi Supply Voltage: 4.956 V
Raspberry Pi Current Current Consumption: 1180.656 mA
Raspberry Pi Current Power Consumption: 5843.566 mW

Traceback (most recent call last):
File "/home/pi/bin/upsPlus.py", line 40, in
batt_current = ina_batt.current()
File "/home/pi/.local/lib/python3.9/site-packages/ina219.py", line 196, in current
self._handle_current_overflow()
File "/home/pi/.local/lib/python3.9/site-packages/ina219.py", line 246, in _handle_current_overflow
self._increase_gain()
File "/home/pi/.local/lib/python3.9/site-packages/ina219.py", line 271, in _increase_gain
raise DeviceRangeError(self.__GAIN_VOLTS[gain], True)
ina219.DeviceRangeError: Current out of range (overflow), for gain 0.32V, device limit reached
UPS Plus Installation is Incomplete! ... failed!
Please visit wiki for more information:.
-----------------------------------------------------.
https://wiki.52pi.com/index.php/UPS_Plus_SKU:_EP-0136.
-----------------------------------------------------.