10 Ways to Ruin Your Mini-Max microcontroller (and lose $69)

Schematic Examplesof some common mistakes

Problem:

No current limiting resistor for LED

I/O pins are logic level control signals only

Problem:

I/O pins must be limited to 5 volts

Always test voltage levels

Problem:

Output pin is driven high by program but low by switch

Set up inputs & outputs before connecting them

Problem:

Battery is connected backwards!

Be very careful with this

Problem:

Two outputs connected together

Watch your pin direction control registers (TRIS)

Problem:

Input voltage exceeded

Power supply must be between +6 and +15 volts

Problem:

Vdd is +5 volts from internal voltage regulator

Do not apply any other voltage to this pin

Problem:Vdd pin cannot power other circuits

(except low power loads like sensors, etc.)

Problem:

Too much current from one I/O port

Use lower current or other ports

Problem:

Pins are sensitive to static electricity

Avoid touching pins

“Logical” NomenclatureWhat do you call the pin state?

• OFF• FALSE• ZERO• LOW• NO• 0 VOLTS• Vss• GROUND

• ON• TRUE• NOT ZERO• HIGH• YES• +5 VOLTS• Vdd• POSITIVE