Testing Phase 1 - Progress Direct Systems Volt Tattler 2 Owner's Manual

Testing Phase 1

1. Apply around 12V D.C. to the board. Watch the polarity. Protection should be in place but we
don't know if everything has been properly constructed yet.
2. If popping, smoke, burning or smell occurs immediately disconnect the voltage and look for a
problem in the assembly. Look for shorts between runs, bad solder joints and improperly
oriented components etc. If you are using a power supply that indicates current it should read
very low (less than 1 milliamp) current. Most power supplies with digital meters will register no
current as the resolution of the digital meters is usually far larger than 1 milliamp.
3. Assuming everything is stable, set your multimeter to measure DC voltage. If your multimeter
is not autoranging set your range above the supply voltage.
4. If you have installed axial lead (a wire at each end of the capacitor) electrolytic capacitors at C10
and C7 then connect the negative lead of your multimeter to the negative lead of one of the
electrolytic capacitors. If you used radial lead capacitors (leads on one end of the capacitors)
you may insert a test wire temporarily into one of the axial lead negative holes. This lead can be
clipped off or left for testing in the future.
5. Using the positive lead, measure the 3.3V supply to the microcontroller (U2) at pin 1. The
voltage must measure near +3.3V. If it is significantly higher or lower disconnect the power and
look for a problem in the assembly.
6. With power still attached move the + voltmeter lead to pin 3 of the microcontroller. You should
see somewhere near 1 volt (assuming 13V was applied as power).
7. Move the + voltmeter lead to the pad for pin 16 of the microcontroller. This should read close
to +3.3V.
8. If everything above looks good disconnect from power and proceed to installing the
microcontroller. If something is not right disconnect power and search for a build error, solder
splash, dry solder joint etc. DO NOT install the microcontroller if any of the above
measurements are significantly off.