AC Measure Unit (HLW8032) buggy?
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There are a number of forum entries talking about the fact that the AC Measure Unit (HLW8032) only works when there is a current flowing through it, i.e., a current to be measured.
Is this a feature or a bug?
At first I thought this must be because the power needed for the electronics on the AC side of the device must somehow be derived from the current being measured. But reading the schematic shows that this is not so. The circuit schematic shows that the "VCC 8032" voltage needed to supply the HLW8032 is provided by the B0505ST16-W5 DC/DC converter which is supplied with +5V from the I2C interface. So the whole thing (i.e. both the AC side and the I2C side) is powered up whenever the I2C connection is made.
So why does the unit stop working when the AC current is 0, instead of just reporting it as 0? And if this is a feature rather than a bug, why is it not mentioned in the documentation?
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@johnericsutton hard to believe that unit is designed in such way to report value only when measured source is above 0...
