Hi, Cressel. 

Could you rough out a sketch of your circuit, including the relay and any 
transistor or FET (if used) part numbers?

Cheers!
Chris Burak

On Wednesday, March 9, 2016 at 6:08:27 PM UTC-7, [email protected] wrote:
>
>
> I am working on a project where I have made modifications to the 
> beaglebone_pru_adc package available on GitHub here: 
> https://github.com/pgmmpk/beaglebone_pru_adc
>
> The code loads in firmware as a *.bin file to run on the pru. It is 
> complied PRU assembly from a *.p file. 
>
> My modifications were to implement a circular buffer in DDR based on the 
> oscilloscope_data() function in the module. This code grabs samples from 
> the adc like in the original code and stick the samples in DDR, but it also 
> updates memory pointers to wrap around. It loops indefinitely and respects 
> the cap_delay attribute.
>
> The board is connected to provide fine grain analog data logging via 
> current transformer and voltage transformer on demand courtesy of the PRU. 
> For instance enabling RMS waveform calculation. I have also written a 
> python class that drives a latching relay. For test purposes I hooked a 
> heavy ~10A load to the relay. The PRU loop runs fine indefinitely using the 
> analog log to display RMS in the python code space. However, the PRU loop 
> continues running after the load is switched on or off but the PRU 
> continues looping only intermittently. The load is resistive, yet clearly 
> the interruption is correlated with switching the load on or off. Sometimes 
> the PRU continues running and sometimes it stops running but only during a 
> switching event.
>
> I understand BeagleLogic.net may be a good lead to follow. In the 
> meantime, I watch for the PRU to stop loading new samples into the DDR. 
> Then I restart it. Very kludgy. My question is have you seen anyone with 
> similar problems switching heavy load and using the PRU? Is there maybe an 
> interrupt you think might be breaking the PRU out of its loop? I can post 
> code if it helps.
>
> I really like these PRUs. Very slick to get real-time capabilities plus 
> the convenience of linux and speed of python prototyping.
>
> Thanks,
> Cressel Anderson
>

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