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brekee12
Posts: 335
Joined: Wed Feb 03, 2016 3:36 pm
Location: HU

piscope

Thu Mar 03, 2016 7:54 am

Dear joan,

I decided to build piscope with a wavegenerator using pigpio. Each RPi is dedicated to the task, however during boot and after that some of the GPIOs are inputs but some is output. Additionally, I would like to interface with 5V systems, too; for experimental reasons. It also make sense to organize the I/Os for easy connection.
I would like to build inputs of piscope with 5V tolerant ICs and 5V outputs for the wavecreation. I have got the idea the output IC should have modifiable power supply voltage needed (e.g. jumper). If you have any suggestion I really appriciate it.
Brekee12
on a Raspberry B+ with whezzy, two Zero with Jessie Light

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joan
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Location: UK

Re: piscope

Thu Mar 03, 2016 10:23 am

piscope doesn't care (or know) if a GPIO is set an an input/output or one of the six other possible modes. It just reads the reported level from the GPIO level register.

I can't help with signal conditioning - my experience is limited to using resistors as voltage dividers.

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brekee12
Posts: 335
Joined: Wed Feb 03, 2016 3:36 pm
Location: HU

Re: piscope

Thu Mar 03, 2016 10:46 am

You do not need to be professional in hardware; the pigpio library shows your professionalizm in software!
I try to do something to make picoscope and pigpiowave more comfortable and usable with other logic levels.
Brekee12
on a Raspberry B+ with whezzy, two Zero with Jessie Light

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brekee12
Posts: 335
Joined: Wed Feb 03, 2016 3:36 pm
Location: HU

Re: piscope

Fri Mar 04, 2016 2:51 pm

Hi joan,

I am working on the board which makes the conversion from 5V to 3.3V and serialization. During the work I have got the idea that in the new version of piscope you may add some feature, a config file which:
- add names to the lines (not only RPi names for the lines)
- save the visible lines as a default
I hope these gives you some idea for further development of your great program. If the board ready, I can send a pieces for you (this will take maximum 10 weeks).
Brekee12
on a Raspberry B+ with whezzy, two Zero with Jessie Light

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brekee12
Posts: 335
Joined: Wed Feb 03, 2016 3:36 pm
Location: HU

Re: piscope

Sun Jun 03, 2018 4:50 am

Hi Joan,

I am dealing with MSP430 and CC2500 radio. All the IOs are used of the uC, so I have to write a bitbang SPI on uC. Something goes wrong. The radio works on the Raspberry SPI, but not on the MSP430. I quickly connect Raspberry GPIO 18-21 to the bitbang SPI and installed PiScope.

At first run I have seen some of the signals, but as I tried to watch signals in detailes but everything goes very slowly or nothing happens it is not clear actually I have little experience with PiScope. I tried to set trigger on CS falling edge but this way also does not work. Do you have an idea how it should set it up to see the signals?
Brekee12
on a Raspberry B+ with whezzy, two Zero with Jessie Light

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RedDragon
Posts: 13
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Re: piscope

Sun Jun 03, 2018 6:22 am

After a long time of offline brekee12 changed to RedDragon.

I forget to write the PiScope is installed on Ubuntu 16 and and it takes a long time to see signals (>5 sec) from RPi and live view does not updates just acquire 3 sec? Something happens because at 3 sec there is a signal change so the program must work correctly, but I do not have idea what can be wrong?

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joan
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Location: UK

Re: piscope

Sun Jun 03, 2018 9:43 am

Perhaps the signals are at too high a frequency?

piscope uses pigpio which samples at 200kHz (once every 5µs) - you may have to slow your data rate to 100kbps or less to reliably capture the data.

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RedDragon
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Re: piscope

Sun Jun 03, 2018 3:48 pm

Thank you for the advice! It works fine. I already got the idea what could be wrong with my program.
Thanks again,

RedDragon

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