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Moonrat: A second-generation portable incubator
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Temperature Readings on UNO U4 Go BAD when operating on 12V, Works on USB Power. #267

Open ForrestErickson opened 3 months ago

ForrestErickson commented 3 months ago

Summary

Temperature Readings on UNO U4 Go BAD when operating on 12V, Works on USB Power.

Further Tests.

Please duplicate the normal and abnormal operation. Measure with an oscilloscope the voltage at the TMP36 output pin in each case. Provide screen shots if possible for operation with both UNO R3 and R4.

ForrestErickson commented 3 months ago

Lee testes Serial number 01 unit. Test conditions: Device Under Test (DUT) powered by USB. The Thermal pad is connected through 100 Ohms and so not drawing much current. Measure the voltage at U1 pin 1, the voltage that represents temperature. When measured with an oscilloscope it is GwInstek GDS-1054B and screen capture software OpenWave. When measured with a multi meter it is EMCO DMR-3800.

This is the oscilloscope measurement for AC ripple

image Note there is probably 16mS ripple which is the 60 cycle AC current here in the USA.

This is the oscilloscope measurement for DC

image When measured with a multi meter it is 0.709 Volts.