VEX Microcontroller V0.5

From VEX Wiki

Links

• VEX 2008 Inventor's Guide - Logic (1.9M pdf, 06-27-08)

Product Information

• Original VEX Microcontroller
• User Processor = Microchip PICmicro® PIC18F8520
• see the Product Page for more information

IO Ports

• Input Impendence: Analog/Digital - The input consists of a 470K pull-up to +5V and a series resistance of 1K to the uP. Interrupts - The input consists of a series resistance of 1K to the uP.
• Digital/Analog as inputs: 3 dB bandwidth of 150 kHz, weak pull-up of 470k-ohms to 5.0 volts, need 0.0 to 0.6 volts for a low and 4.0 to 5.0 volts for a high
• Interrupts as inputs: 3 dB bandwidth of 150 kHz, weak pull-up of 47k-ohms to 5.0 volts, need 0.0 to 0.6 volts for a low and 4.0 to 5.0 volts for a high
• Digital/Analog Interrupts as Outputs: As outputs these ports can drive an open circuit to 0.6v or lower for a low and 4.0 volts or higher for a high. They can drive a 1 mA load to 1.6v or lower for a low and 3.0 volts or higher for a high.
• PWM Outputs: As outputs these 8 ports can drive an open circuit to 0.6v or lower for a low and 4.0 volts or higher for a high. They can drive a 1 mA load to 1.0v or lower for a low and 3.6 volts or higher for a high.
• Digital input Freq: 50 KHz (typical)
• Analog input Access: 10 μSec
• Pinout:
  • Digital/Analog, Interrupts, Motor Outputs: Outside pin (closest to the controller edge) Ground
  • Digital/Analog, Interrupts: Center pin (or middle pin) + 5 Volts, 1 Amp Max combined total from all pins
  • Motor Outputs: Center pin (or middle pin) + Battery Power, 4 Amps Max combined total from all pins
  • Digital/Analog, Interrupts, Motor Outputs: Inside pin (furthest from the controller edge) Signal / Control line

LED Indications

• BATT POWER
  • Green - Flickering = Normal
  • Red = Dead - Recharge now
  • off = No Detectable Power

• PGRM STATUS
  • Green - Slow Flash = Ready for Download
  • Green - Fast Flash = Downloading
  • Off = Normal

• Rx 1 STATUS
  • Green - Flickering = Normal Radio Link
  • Off = No Radio Link

• Rx 2 STATUS
  • Green - Flickering = Normal Radio Link
  • Off = No Radio Link

• EYE
  • Amber - Flash 4-5 secs = Normal
  • Amber - Fast Flash = Autonomous

RX1 or RX2 Ports

• Pin 1 - Power +5 volts (the right most pin when looking at the front connector on the VEX Controller)
• Pin 2 - Receiver
• Pin 3 - Gnd
• Pin 4 - Tether Detect (the left most pin when looking at the front connector on the VEX Controller))

Serial Port

The Serial Port is at TTL Levels. Connecting higher voltage Levels to this port can damage the VEX Controller.

• Pin1: TTL-CTS (the right most pin when looking at the front of the Serial Port connector on the VEX Controller)
• Pin2: + 5V out (1 Amp max from all external +5 V pins combined)
• Pin3: TTL-RTS
• Pin4: Ground
• Pin5: TTL-RX in
• Pin6: TTL-TX out (the left most pin when looking at the front of the Serial Port connector on the VEX Controller)