Change Log

Rev 1.0

• Turn signal mapped to PA8 but that is not an ADC Pin

  • Resolution: Rev 1.1

Rev 1.1

• Remapped stalk input from PA8 to PA5

Surge Protection Research:

What is Surge Protection/ESD?

Electrostatic Discharge (ESD) can be caused by a seemingly random surge in Voltage due to static electricity or electrostatic induction. Since the driver interacts with the controls a lot, there is a chance for ESD to occur from static electricity. Due to the random voltage spike, microcontroller pins can easily get damaged, so surge protection is required.

Best Practices:

• Keep sensitive components away from high voltage components

• Short routes/wires

  • short wires = less inductance = less EMI = less ESD

• Ground Plane in PCB stackup

  • can accept ESD-induced currents

• Do not run wires parallel to any wire through which ESD pulses might travel (due to EMI inducing voltages in other wires)

Potential Fixes:

• Transient voltage suppressor (TVS) diodes (or Zener diodes)

  • Unidirectional - good if the polarity of an ESD event is known with respect to the system I/O

  • Bidirectional - good if the polarity of an ESD event is unknown with respect to the system I/O

  • Weakness: Transient oscillations can cause TVS diodes to fail

• ESD suppressors

  • generally use TVS diodes

  • ex. https://www.digikey.ca/en/ptm/c/comchip-technology/esd-and-esd-suppressors

• Reverse bias diodes for clamping voltages

• Relays

Example Circuit to Avoid ESD

Open

• The TVS diodes ensure that the voltage surge is regulated

• The resistor is used to limit the current (protecting the diodes from ESD failure)

Readings

https://www.digikey.ca/en/articles/protecting-inputs-in-digital-electronics

Beginner’s Guide to ESD Protection Circuit Design for PCBs

Basics of Surge/ESD and Protection Components

Driver Display(s)

per regulations, commercially available electronic panel meters with internal batteries do not need to be powered by the main battery pack. These displays can be used to our advantage to save more power from the main battery pack.