SiLab-Bonn/basil

Setting power gives error

Closed this issue · 5 comments

themperek commented

@laborleben
'''
self.dut['ADAPTER_CARD'].set_voltage('VDDD1', 1.2)
File "/basil/basil/HL/FEI4AdapterCard.py", line 161, in set_voltage
self._set_dac_value(value=value, **self._ch_map[channel]['DACV'])
File "/basil/basil/HL/FEI4AdapterCard.py", line 85, in _set_dac_value
self._intf.write(self._base_addr + self.MAX_520_ADD, array('B', pack('BB', channel, value)))
error: ubyte format requires 0 <= number <= 255
'''

laborleben commented

This is known, some adapter cards do not reach 1.2V. It might also be that the calibration EEPROM is broken or is not set at all.

themperek commented

For this module I cannot see lower then 1.2. For 1.2 I get DAC raw value of 272 which is > 255 (allowed). It works with 1.3.
Should it log a warning and set 255?

laborleben commented

yeah right a log warning should be printed. try: ...set_dac_value() except Error: ...logging.warning()

But be careful: sometimes an error is also given when setting to 0V (also outside the range of the DAC). Simply setting the DAC to maximum (e.g. 255) is not a good idea in this case.

themperek commented

One can also set default to 1.25V or something and this goes away. Should not meter for the chip operation.

laborleben commented

IMHO not touching the DAC and not setting the DAC to something else is the best solution. I would keep it as it is and implement a nicer error message. The user has to decide what to do.