R.E.M. II v4.1

Tweaking perfection

After the trial run of v4 models, it was time to add in the necessary fixes and tweaks to make the REM II line-up near perfect! These are also the first boards to sport the new company name. 52 units were ordered to see how things went.

The main fixes include fixing the MicroSD Card footprint, Swapping the TCU and Bluetooth Comm pins for max CPU speed, adding in an op amp for signal out possibilities, swapping the free analog pins for more control, adding 5v voltage dividers to those pins for more realistic analog reading, and gold plating for extra bling.

On the nerdier side of things, I took care of an odd voltage spike due to a button resistor value being too low, and my absolute favorite fix of changing the lcd contrast knob from the 5v feed to the teensy’s 3.3v feed. Now no matter where power is input, the voltage will always be stable which means the lcd contrast will too, and for true bonus nachos now it will also be less sensitive so I can really dial in the perfect spot.

  • New Features:
    – MicroSD Card Slot
    – Faster CPU Speed
    – Free Pins have more functions
    – Signal Output for experimental tuning
    – Gold plated terminals
  • Features:
    – 87-90 4.0L M/T & A/T ECU Support
    – 86-90 2.5L M/T & A/T ECU Support
    – AW-4 TCU Support
    – 16×2 RGB LCD
    – Check Engine Light
    – Auto Dimming Display
    – o2 Heater Relay reading
    – RTC clock module
    – Power and Jack breakout pins
    – 3 Arduino breakout pins for Inputs or Outputs
    – Surface Mount components
    – Fused Circuit Protection
    – PJRC Teensy 3.2
    – PCB Diagnostic Adapter
    – Original Price: $110
  • Compatible Upgrades
    – Optional Bluetooth Module
    – Optional Gyroscope
    – Optional In/Out adapter to control fans or read extra signals
  • Known Bugs
    – Bluetooth module is powered off 3.3v instead of 5v, but still seems to function properly.
    – Signal Out Op Amp is not rail-to-rail and can only go down to 0.8v.
    – 5v Voltage Regulator may overheat with additional add-ons (Rare)