FPGA GPIO pins issue (J18)

I m trying to connect arduino SPI pins with limesdr FPGA GPIO pins (J18) but i m using ordinary jumper cables for connection no data is writing or reading via on JTAG 18 pins so is JTAG connector cable is necessary or is there any other issue i m dealing with because sometime arduino read data (wrong data) from data registers biut most of the time not @zack i m follwing your arduino to FPGA configuration file and limesdr to arduino .ino file i connect arduino SPI pins with 1-9 of FPGA GPIO pins

1 Like

You do not need JTAG.
Try shorter wires for SPI connection.
Is the ground between LimeSDR-USB and Arduino connected? I can not see from the picture.

limesdr J18 pin 9 (GND) is connected with Arduino SPI GND pin only i missing some other GND pin?
image

If GND pins are connected, then it is OK.

ALTERA FPGA and limesdr chip get very hot when i connect both arduino and limesdr with laptop is it normal? and sometime it reads right data dataread