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
- 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
- servo4 : Quad 13-bit servro 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. Seperate power lines are handy if you want to power a servo or other circuit from the header.
Hardware: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.