Pi VM205 Oscilloscope for Testing another Pi

[RDS]

I have one of my Raspberry Pi's set up permanently as an Oscilloscope using the VM205.
I have successfully used the Oscilloscope to monitor the DCC signal on a Model Railway, so I know it works but I am now trying to use it to monitor another Pi, in particular the output from a BPW85 Photo Transistor.

I have so far been unsuccessful because with the Oscilloscope Leads one way around on the signal, it froze the BPW85 Pi and with the leads the other way around, no signal is detected, despite my usual program that monitors it, showing that the signals are present.

I have been connecting the Pi Oscilloscope Leads directly to the other Pi.
Should I have some other electronics in between?

[MarkHaysHarris777]

Could you use this?

[RDS]

@MarkHaysHarris777
Thank you.
I was not aware of Piscope but it looks like it does everything that I require in this instance.
Whether or not, I can get it up and running maybe another thing though!

[MarkHaysHarris777]

@MarkHaysHarris777
Thank you.
I was not aware of Piscope but it looks like it does everything that I require in this instance.
Whether or not, I can get it up and running maybe another thing though!

Don't thank me, its the brain child of Joan (she is active here and may comment depending on her mood) on that same site pay attention to the pigpio library (it rocks too!) she has version three (3) out now...

[DougieLawson]

pigpio is now delivered as an ready installed part of Raspbian.

[MarkHaysHarris777]

pigpio is now delivered as an ready installed part of Raspbian.

I'm confused about that, because I thought I had the latest Raspbian on my three PI3B units, and none of them have pigpio as yet... I was getting prepared to load v3 actually...

... so what do we mean that its loaded by default; I guess an update upgrade doesn't pull it in, ey?

[rpdom]

what do we mean that its loaded by default; I guess an update upgrade doesn't pull it in, ey?

It means that if you download and install the latest Raspbian image you will find that it is already installed.

If you are upgrading from an earlier image you will need to install it manually

[MarkHaysHarris777]

what do we mean that its loaded by default; I guess an update upgrade doesn't pull it in, ey?

It means that if you download and install the latest Raspbian image you will find that it is already installed.

If you are upgrading from an earlier image you will need to install it manually

Thank you for the clarification! 'preciate it...