Unicorn Inchworm+ Upgrade & Experimenter

The first Unicorn PCBs are done and an Opps!

The Unicorn PCBs are here, they look great but a small opps crept in while I was editing the silkscreen layer (I bumped Q1 too high and it touches a trace shown in purple!). Luckily it does not affect normal operation of the Unicorn and the simple solution is to omit LED1 and R7 (designed for Experimenter use and has no effect on the USB Inchworm+ upgrade).

Unicorn USB Upgrade for Inchworm+ & Experimenter Preview

What is the Unicorn...

  • MPLAB compatible USB upgrade for the Inchworm+ (simply snaps to the bottom of the Inchworm+)
  • Many times faster than the RS232 version of Inchworm
  • Uses your USB port for power 250ma max* to power itself, Inchworm+ and your target project.
  • For extra power use the Inchworm+ onboard power supply 1A max
  • Uses MPLAB firmware client driver

 

Unicorn can transform in to a USB Experimenter...

  • 128x64 GLCD connector with backlight control
  • 2x16 LCD with backlight control
  • USB port for fast communications
  • RS485 for long range 4000', multi-node (32 devices) serial communications
  • I2C option with socket for 24LCxxx EEPROM
  • 4 pushbuttons on PCB
  • 4x4 keypad connector option
  • iButton / 1 Wire connector
  • LED
  • ICD2 Inchworm connector for reprogramming & debugging

* Although USB can supply up to 500ma, 100ma is the maximum recommended. There is a 250ma self resetting thermal fuse on Unicorn.

Unicorn Assembly Instructions

To use your Unicorn as a Inchworm+ USB upgrade just program it with Unicorn.hex You can then attach your Unicorn to the underside of an Inchworm+ (like the illustration on the bottom of this page). You can always remove and repurpose the Unicorn for use as an experimenter at any time.
Note: the Inchworm+ when running in USB mode is somewhat faster than the RS232 mode.

Some useful sites to get you started

Here's a link to things you can do with a 18F4550 Create USB Interface

To get you started with both LCD & GLCDs I've linked an excellent LCD Info Page by Dincer Aydin with simulator for both Character and Graphic LCDs

And this is the Inchworm+ mounted directly to the Unicorn, the pair appear in MPLAB as a MPLAB firmware client. You have to program the 18F4550 with a special 18F4550 USB client first. 12mm spacers are ideal for mounting when used this way. I've use this combination for all my project work, and although you can power your projects with USB power you should be aware that USB very limited in the amount of current it can supply. Typically 200ma before the power will sag (this can cause the debug mode to reset unexpectedly). Low power requirement kits like Firefly work fine with USB power but high current kits like Dragonfly will also require an external DC supply connected to the Inchworm+. This method uses almost no USB power and can supply almost 1A to your target project. Use external power with any loads greater than 100ma. Motors / Servos / Relays etc...

The Inchworm+ mounted via 40pin header to the Unicorn makes a fast USB programmer / debugger.