Limesdr board output voltage issue

Dear All
I connect limesdr board with USB 3.0 port of laptop and measure voltage at output of FPGA GPIO pins J18 and found that measure voltage was 0.82-1.2V now i m very curious because i want to connect those pins with Arduino DUE SPI pins and when connect MISO pin of Arduino SPI with FPGA GPIO pins no voltage at both pins otherwise if i don’t give power to limesdr board then arduino SPI show 3.33V while sending data through slave line it means every thing is good on arduino side and also both Altera Cyclone IV and LMS7002m get very hot.