MCC 172 multi-hat synchronous run with external trigger

[dualsbiker]

Hey there,

I'm using 4 mcc-172 boards on a Raspberry Pi 2 and try to build a script, that gets synced data from each hat. Master is hat 0. I have problems in understanding the code and wanted to ask, if there are more examples than in the python library?

The example script multi_hat_synchronous_scan.py is good, but it measures just one time all 4 hats. I want to read again and again, like the continuous_scan.py script.

How does the trigger input works? Do I have to put a signal with a frequency to it or is it just a trigger, that only starts reading data and does not affect to any data acquisition?

BR Basti

[Jeffrey]

You can make the mult_hat_synchronous_scan.py example continuous by editing lines 74 and 75. You add an additional option flag to the existing.

Original: OptionFlags.EXTTRIGGER,

modified:  OptionFlags.EXTTRIGGER + OptionFlag.CONTINUOUS,

Attached is a 3, MCC 172 version of this example configured for external trigger and continuous scanning.

The trigger needs only be applied to the Board 0 MCC172 hat.  When armed, it is looking for a single rising edge (by default)

Regards,

Jeffrey

 

three_hat_sync_cont_scan.py

[1zhangyo]

On 6/4/2022 at 2:29 AM, Jeffrey said:

When armed, it is looking for a single rising edge

Hi,

   Could you teach me how to start the scan on a rising edge of TRIG. In other words, I don't know how to run the code with external trigger.Thanks.

Regard,

1zhangyo