./test_loragw_cal -a 915 -b 916 -r 1257 -n 10 -k 1 -t 0
lgw_board_setconf:437: Note: board configuration; lorawan_public:1, clksrc:1
lgw_rxrf_setconf:498: Note: rf_chain 0 configuration; en:1 freq:915000000 rssi_offset:0.000000 radio_type:2 tx_enable:0 tx_notch_freq:0
lgw_rxrf_setconf:498: Note: rf_chain 1 configuration; en:1 freq:916000000 rssi_offset:0.000000 radio_type:2 tx_enable:0 tx_notch_freq:0
Library version information: Version: 5.0.1; Options: native;
Radio type: 2
Radio A frequency: 915.000000 MHz
Radio B frequency: 916.000000 MHz
Number of calibration iterations: 10
Calibration command: brd: 0, chip: 1257, dac: 3

Note: SPI port opened and configured ok
Note: SPI read success
lgw_connect:532: INFO: no FPGA detected or version not supported (v255)
Note: SPI read success
lgw_connect:555: ERROR: NOT EXPECTED CHIP VERSION (v255)
ERROR: FAIL TO CONNECT BOARD