DIP Switch on FPGA

[BZMContact]

Hello!

I started learning VHDL this semester and, although the university has prototyping boards, I decided to buy my own. However, the board I bought (Cyclone IV Intel+Altera) did not come with any DIP switches. It only has GPIOs. How could I connect these switches to the FPGA board? And the LEDs to generate the results in binary, how should they be connected to avoid burning them or damaging the board?

The first project I would like to implement is a 4-bit adder.

Thank you very much for your help.

 

[barry]

You could simply connect the dip switch between the GPIO and ground, and configure the GPIO to have a pull-up. Or add an external pull-up.

Are there buffers on the board? Connect the led, through an appropriate resistor, to the buffer output.

But, to be honest, your setup there is almost guaranteed to damage the FPGA. you really don’t want the pins of the FPGA connected to long wires flopping around like that.

 

[BradtheRad]

J usually stood for Jumper years ago. That was when IDE-style connectors were the norm. Disk drives usually had a few pins at an edge for jumpers. These were small plastic black rectangular things that you pushed onto certain pins in order to designate characteristics of the drive. You removed them with tweezers or hook tool.

Also common was a flat ribbon cable which went on those pins fiting inside the long compartment containing the dual rows of pins. Either a single flat ribbon or twin flat ribbons. If you can discover an identical connector you can hook it up to your long dip-switch on the breadboard.
However you must make sure whether direct shorts are permitted. First further effort may be needed.

 

[FvM]

Can specify the exact evaluation board type and post a link to the schematic .pdf or attach the schematic here?

The most simple method is to enable internal weak pull-up in pin planner tool and use a switch to ground.

I see no specific risk of input damage as long you are operating the board on your desk only.

LEDs can be connected the same way as the internal LEDs are on the board, with an appropriate series resistor.

Looks similar to Alinx AX301.

 

[BZMContact]

You could simply connect the dip switch between the GPIO and ground, and configure the GPIO to have a pull-up. Or add an external pull-up.

Are there buffers on the board? Connect the led, through an appropriate resistor, to the buffer output.

But, to be honest, your setup there is almost guaranteed to damage the FPGA. you really don’t want the pins of the FPGA connected to long wires flopping around like that.

Thanks, Barry. But fortunately, I haven't powered the board yet as shown in the photo. I made the connections just to give you an idea of what I wanted to do.

 

[BZMContact]

Can specify the exact evaluation board type and post a link to the schematic .pdf or attach the schematic here?

The most simple method is to enable internal weak pull-up in pin planner tool and use a switch to ground.

I see no specific risk of input damage as long you are operating the board on your desk only.

LEDs can be connected the same way as the internal LEDs are on the board, with an appropriate series resistor.

Looks similar to Alinx AX301.

Thanks for the tips, FvM. Attached is the schematic of the board.

 

[KlausST]

Hi,

basically you connect the DIP switches the same way as the pushbuttons on page#7.

Klaus

 

[FvM]

Schematic is almost identical to Alinx AX301.

LED series resistor between 220R and 470R. DIP switches don't need external pull-up if you enable FPGA internal pull-up for respective pins, as already stated in post #4. No external VCC connection needed.