GVS-32U4

Features

The GVS-32U4 Revision X2 board is the second generation of GVS-32U4 board based on the previous X1 Revision board. The board includes the features:

• Arduino Leonardo compatible
• Program board using the Arduino IDE
• Atmel ATmega32U4
  • Low-power
  • Max. Operating Frequency: 16 MHz
  • 8-bit AVR RISC-based microcontroller
  • 32KB flash program memory
  • 2.5KB SRAM
  • 1KB EEPROM
  • USB 2.0 full-speed/low speed device
  • 12-channel 10-bit A/D-converter
  • Pin Count: 44
  • Max I/O Pins: 26
  • Ext Interrupts: 13
  • USB Transceiver: Yes (1)
  • USB Speed: Full Speed
• USB-Mini connector
• Standard connection as USB peripheral
• ATMega32U4 has a built in USB interfaces so it does not require an FTDI part
• Three flexible power options - Jumper controlled
• Power from the USB port
• The USB input is polyfuse protected
• Power from External VIN pins (> 6.5V required)
• Uses an on-board Low Dropout (LDO) Voltage Regulator (1.4V min drop)
• Embedded power option
• Power from reverse powering one of the GVS connector power pins
• Red Power LED
• GVS connectors for all input/output pins
• GVS wiring is compatible with standard servo pinouts on 0.1" pitch
• Note that typical servo connectors are wider than 0.1"
• GVS wiring provides the ultimate in flexibility since individual sensors and outputs can be fully connected with standard 3-pin to 3-pin cables
• Pololu is a good source of 0.1" pitch crimp connector housings and wires with pre-crimped terminals
• Four solid 4-40 screw mounting holes
• Mounting holes are spaced at 41mm x 41mm
• Board size is 49mm x 49mm (less than 2"x2" which is smaller than the Leonardo 2.7" x 2.1")
• Rounded board corners for installation into chassis with internal rounded corners such as inexpensive plastic project boxes
• HWB jumper for programming part over the USB
• Program using ATmel FLIP
• Pullup resistor to VCC
• Compatible with Arduino Leonardo bootloader

Improvements from GVS-32U4 Rev X1 Board

Changed signal legends on headers from ATMega32U4 pin names to Arduino Leonardo pin names
Added Serial Number marking area (Mark using Sharpie)
Put all configuration headers in the bottom left corner
Moved Power header to bottom left corner and labeled more clearly
Moved Input Voltage header to bottom left and labeled more clearly (EXTernal power and USB power)
Moved Reset header to bottom left and labeled more clearly
Oriented all headers so that pin 1 is to the outside of the PCB and is wired to Ground
Rings
Board rings are Ground on outer ring
Voltage on center of ring
Signal on the inner ring
Added GVS silkscreen to all ends
Added pbworks path to bottom silkscreen (our old wiki host)
Increased size of component silkscreens
Made PCB larger (49mmx49mm) for cheaper build by seeedstudio.com fusion service
Further Improvements Needed to the X2 Board
There are two D6 markings on the board. There should only be one D6. Marking near C5 should be D5.
Add an L-C low pass filter to AVCC (Analog VCC).

GVS-32U4 Mechanical Dimensions

Leonardo Port to Arduino Pin Mapping

From the Arduino Leonardo page:

Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data using the ATmega32U4 hardware serial capability.
Note that on the Leonardo, the Serialclass refers to USB (CDC) communication; for TTL serial on pins 0 and 1, use the Serial1 class.
TWI: 2 (SDA) and 3 (SCL).
Support TWI communication using the Wire library
External Interrupts: 2 and 3.
These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details.
PWM: 3, 5, 6, 9, 10, 11, and 13.
Provide 8-bit PWM output with the AnalogWrite function.

Extended pins

Extended digital pin mapping
MISO as digital pin 14
MOSI as digital pin 16
SCK as digital pin 15
RXLED as digital pin 17
A0 as digital pin 18
A1 as digital pin 19

GVS-32U4 Rev X1

The GVS-32U4 uses the same Microprocessor as the Arduino - Leonardo.This includes a built-in USB interface. This board takes that processor and surrounds it with GVS (Ground, +5V, Signal) pins. This allows for easy connections to a variety of peripherals.

VSEL/+5sel Jumper
Position	Function
1-2	Power the board from USB
2-3	Power the board from the On-board Regulator
None	Power board through GVS pins
Revision X1 Checkout Notes
The programming pin, HW, should be on PE2, not PF2
[Rework] - Added pull-up resistor from PE2 to Vcc pin adjacent - added to rear of PCB.
dfu-programmer for native programming using the built-in bootloader
Getting the Leonardo Bootloader onto the GVS-32U4