What is "Test Mode" in the Capture -> Aquisition dialog

[alanbur]

Simple question but I haven't been able to find the answer: What does the 'Test Mode' checkbox do in the Capture -> Aquisition dialog do? Does it put the OLS into the mode where it outputs a test signal on the wing connector?

[jawi]

Yes, checking the "test mode" enables the output of a test pattern on the unbuffered wing connector which can be used to test your OLS...

[alanbur]

Thanks - was selected by when I started up the new client, just wanted to be sure I should turn it off :-)

[cire831]

what does the test pattern look like?

I assume you then connect from the unbuffered wing pings over to the buffered pins. Is that correct?

[tayken]

It looks like an 8-bit counter signal, one pin with high freq, next one half that one and so on.

Yes, for the test mode, you connect unbuffered pins to the buffered ones. The unbuffered ones are outputting the signal.

[cire831]

It looks like an 8-bit counter signal, one pin with high freq, next one half that one and so on.

Yes, for the test mode, you connect unbuffered pins to the buffered ones. The unbuffered ones are outputting the signal.

So I hooked up 8 bits and this is what I see... (Doesn't look like an 8-bit counter signal)

I tried to paste a graphic but i seem to not to know how to do that.

chanl 0 has a period of 320 ns. chanl 1 - 18.55us
chanl 2 - 320 ns, chnl3 - 18.55us

etc.

this is with ols client of 0.9.6-b4 + off the git repository (beyond b4).

ols hw f/w is 3.0 running Demon Core 3.07

[jawi]

The test-signal is generated from the FPGA (hard coded); I believe its main frequency is related to the acquisition clock, while the 2nd frequency is a division of that.

DemonCore also has another test feature, I'm not sure what pattern is used for that, but it is also hardcoded...

[Max]

what does the test pattern look like?

The attached file is a sample of the OLS test mode output from the unbuffered wing connector, connected as follows:
unbuffered wing connector pin 0 => Channel 0 pin 0
unbuffered wing connector pin 1 => Channel 0 pin 1
unbuffered wing connector pin 2 => Channel 0 pin 2
unbuffered wing connector pin 3 => Channel 0 pin 3
unbuffered wing connector pin 4 => Channel 0 pin 4
unbuffered wing connector pin 5 => Channel 0 pin 5
unbuffered wing connector pin 6 => Channel 0 pin 6
unbuffered wing connector pin 7 => Channel 0 pin 7

The inside numbering scheme was used for channel 0.

I hope you or someone else finds the sample test capture interesting.
---
Max

[chemary]

I soldered the unbuffered wing connector to see what the test capture looks like and its like Max posted. Then I enabled RLE and run it again and I get what looks like noise, is that normal?

[Drone]

I think this self test mode is explained (rather poorly IMO) in Gadget Factory's "screencast" at this page:

http://www.gadgetfactory.net/logicsniffer/index.php?n=LogicSniffer.SelfTestMode

Here they use an "IDE" cable (they don't specify what type, I would assume it is an older 40-pin IDE F/F cable) to connect a user-populated wing header (the OLS doesn't come with a populated wing header) to the buffered pins in order to see the self test output in "loopback". I haven't tried it myself yet...

[Aeroengineer1]

Is there an (easy) way that we could use this output as a variable duty cycle pwm? I know that others have talked about higher end signal generation, but I was wondering if anyone has though of this simple addition that may not be too hard to get working. Later this could then potentially be extended to being able to talk with some digital devices, but for me as most of the stuff that I am working on are RC hobby projects, this would allow me to do them without needing a separate servo tester for a signal, or a different tool to represent the data stream that the RX gets.

Adam