Demand Peripherals     Robotics and Automation Made Easy

GPIO4: Quad General Purpose Input/Output Card

The Quad GPIO card gives direct access to four pins on the FPGA. Output is at 3.3 Volts and input can be either 3.3 or 5 Volts.


- FPGA input, output, or bidirectional access
- 3.3 or 5 Volt input
- 3.3 Volt output
- Pin headers or screw terminal connections

The GPIO4 card is a good choice for any of the following peripherals:
  - gpio4 : General Purpose I/O
  - ping4 : Quad Ping))) sensor interface
  - in4 : Quad binary input
  - out4 : Quad binary output
  - quad2 : Dual quadrature decoder
  - count4 : Quad event counter
  - pwmin4 : Quad PWM input
  - pwmout4 : Quad PWM output
  - ws28 : Quad WS2812 LED controller
  - servo4 : Quad 13-bit servo controller

The pin-header version has four three-pin headers for I/O and has screw terminals to set the voltages on pins 2 and 3. Separate power lines are handy if you want to power a servo or other circuit from the header.



The schematic and layout of the two GPIO4 cards are shown below. The Eagle schematic and board files for the pin-header version are available here: gpio4.sch and gpio4.brd. The Eagle schematic and board files for the screw terminal version are available here: gpio4.sch and gpio4.brd.

The bill-of-materials files are available here gpio4.txt and here gpio4-st.txt.



FPGA Defined Peripherals
User Interface
FPGA Configuration
FPGA Buttons & LEDs
Host Tx/Rx Interface
AVR Interface
Stereo Audio Amplifier
Text LCD and Keypad
Quad WS2812 Interface
Quad Slide Pot
IR Recv/Xmit
6 Digit LCD
RC Decoder
Keyfob RF Decoder
Rotary Encoder Interface
Quad Touch Interface
Motion Control
Dual DC Motor Controller
Dual Quadrature Decoder
Quad 13 Bit Servo
Bipolar Stepper Controller
Unipolar Stepper Controller
Simple Input / Output
Quad Binary Output
Quad Binary Input
Octal Input/Output
32 Channel Binary Output
32 Channel Binary Input
Quad Serial Output
Octal Serial Output
Octal 12-bit ADC
Quad Ping))) Interface
Pololu QTR Interface
Octal SRF04 Interface
Generic I2C
Generic SPI
Octal 8-Bit DAC
Quad Digital Potentiometer
Quad PWM Output
Quad PWM Input
Quad Event Counter
Real Time Clock
Dual Pulse Generator

Interface Cards
Control Cards
User Interface
Stereo Audio Amplifier
IR Recv/xmit
Six Digit LCD Display
Keyfob RF Receiver
Rotary Encoder
Quad Switch Card
Text LCD / keypad
Quad Slide Pot
Quad Touch Interface
Motion Control
Dual 7-amp H-bridge
Quad Open Drain Driver
Quad 10 Amp Relay Card
Input / Output
Octal 8-Bit DAC
Quad Digital Potentiometer
Octal 12-bit ADC
Octal SRF04
I2C Prototyping
SPI Prototyping
USB 2.0 Hub
Real Time Clock
Octal Input/Output
32 Channel Input
32 Channel Output
Power Distribution Card
15 Amp Power Distribution
5 Volt Switching Regulator
ATX Power Break-Out Card
Disk Drive Power Break-Out
MP43 Aluminum Mounting Plate
WW4 Large Prototyping Card
WW2 Prototyping Card
WW1 Small Prototyping Card
SMP SMD Prototyping Card