openscope Open Scope Inquiries

[victagayun]

How to hack digital input from 3V3 to 5V? Would voltage divider be enough? 

Are some of the digital input (used as logic analysizer input) can be used as analog input (but limited to 3v3)? If so, is there any way to utilize "5 dedicated 3.125MHz 12-bit ADCs" for oscilloscope functions? 

I believe you might be using 2pcs LMV116 as your 2ch analog input and eventually goes to the MCU, how to hack and add 2 more of these op-amp to become 4ch scope in-case if some of the digital input can be used as ADC. I could Add those extrenally.

You said two interleaved ADC are used for one channel, is it done and connected through hardware or only thru software implementation? That means only 1-2 channels left for extra ADC (in-case above question is possible) with 3MSPS? 

Do expose unused pins or I/O that can be used and connected externally?

If the above question is not possible, would be the logic analyzer pins can be used instead? Can be used for external LCD or something.

I hope I am not asking too much. More power.

[Kristoff]

Hey Victagayun,

I suggest using a level shifter if you need to go form 5v to 3.3v.  For example the PmodLVLSHFT would work.

The digital inputs cannot be used as Analog Inputs.  The ADC channels are interleaved to get better resolution on the Osc channels.

There is no simple way to extend the device to 4 Osc channels.  Our default firmware uses virtually all of the hardware resources on the MZ to achieve the shipping features set.  In addition to the pin availability you have consider things like timers, ISRs, peripheral mapping, DMAs, etc.  

The Logic Analyzer pins can be used as GPIO.  You could modify the firmware and bitbang some protocols on these pins but it would likely get interrupt by or interfere with the default device operation.

Let us know if you have more questions.

Thanks!

-Kristoff