no error message for min or max values
no error message for min or max values

Setting, eg, a positive DAC to 0 results in the message "Voltage too low for set span, DAC set to max value", which is imho not necessary and can be annoying. Maybe changing the first if statement (line 260 and 265) to just > and < works as well, i didn't look at it in details
peendebak/SPI-rack,Rubenknex/SPI-rack