Pi------------------DAC---------------------Pi
5V---------------P1-------P8----------------GND
5V---------------P2-------P7----------------MOSI
LED-B------------P3-------P6----------------SCLK
LED-A------------P4-------P5----------------GPIO22
GPIO22 could be any Pi GPIO of your chosing, use its numeric value with -cs
sudo ./runDAC8552.sh -s 0x0 -cs 23 -t trace -vout 2.1 -vref 5.0 -chn channel_A
Channel A set to approximately 2.1 V
sudo ./runDAC8552.sh -s 0x0 -cs 23 -t trace -vout 5.0 -vref 5.0 -chn channel_B
Channel B set to approximately 5 V
sudo ./runDAC8552.sh -cs 23 -vout 3.0 -chn channel_B
Will operate with the default trace_level 'info', SPI0 and -vref 3.3