3.6 Hardware test
The Hardware test screen provides a comprehensive diagnostic of your hardware.
All 19 IO signal states are shown; both the digital readings of the pin (0 or 1) and the analog level
0 to 4095 for GPIO pins 0 to 8.
Date, Time and the GPS parameters are all derived from the serial data stream arriving from the
GPS module.
The screen also tests the Si5351A Synthesizer and shows the LM75 temperature (in Kelvin) and
the measured battery voltage.
The data is updated once per second.
If there are any fails, they are coloured red. A common failure is all the GPS parameters being
coloured red; this is normally (hopefully) just a matter of waiting longer for a GPS satellite fix. It
can take several minutes, depending on the sky view and how well you built a GPS antenna.
U4B operating manual Rev 1.00
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