I have purchased the above module. Allegro’s datasheet indicates a sensitivity of 200mV/A, as does the wiki entry on Seeed Studio. In practice I am getting 35mV/A. I have tried many inputs from 0 to 2A DC, measured with lab power supply and multimeter. Zero offset is 1.54 V. I have tried 3.3 and 5 V inputs. Have I received a broken module?
Hi rowsto64!
I am sorry to inform you the product is out of stock now so that we cannot have a test for this module. I will receive you in this thread when the module is available.
Thank you. But does the data sheet not specify the correct resolution? Regardless, I will wait for your test, as the product is still of interest if 200mV/A is correct.
Hi.
I arrive late.
It happens exactly the same to me.
I bought 9 units, 2 in June and 7 in July.
All of them in DIGIKEY.
First 2 units from June measure fine at 200mv/A
But 7 units from July measure wrong giving around 30-40mV/A
All of them with exactly same setup.
Did you find any explanation?
From my point of view these boards have to be defective.
Thanks and regards
No, no explanation or adequate response. I have decided they are defective. Thank you for confirmation of the problem. At least you have 2 working!
I’m having exactly the same low sensitivity problem with the Grove +/- 5A ACS70331. Over the full range 10 A (-5 to +5 A) of the sensor, I’m getting a sensitivity of 36.8 mV/A instead of 200 mV/A. I was expecting to make calibration adjustments to both the zero-crossing and the sensitivity. The zero-crossing only needs a small adjustment (0.015 V), but the recorded sensitivity of 36.8 (vs 200) tells me that there is a flaw in the device. I sent my data/graph to Seeed last night (11/4/23), I hope they can locate a working replacement. It’s weird that Argui recorded the same sensitivity error (30-40 mV/A) as I did. I wonder if the wrong chip got placed on a batch of these breakout boards.