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Topic: Saleae (clone) help with pins (Read 14016 times) previous topic - next topic

acboother

I just purchased a cheap logic analyser off eB4Y. A Saleae clone I now realize.

No manual or software!

Downloaded some s/w from Saleae (any others?) and got it to display signals on screen. Just one thing I can't figure is how to use the CLK input.

Some of these clones seem to have two GND pins and some, like mine, have a GND and a CLK.

So how would I use the CLK pin?

Thank you, Alan


Peter_n

Find the matching Saleae product.

Are you sure it is an input ? Or is it perhaps a GND with a wrong label ?
Can you give a link to what you have bought, and a photo of what you have ?

larryd

I have real  Saleae.
There is no clk input.
The inputs are simulateousely clocked by an internal asynchronous clock that you set the speed in software.

.
No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

acboother

#3
Jun 24, 2015, 09:42 am Last Edit: Jun 24, 2015, 09:48 am by acboother
Here is the link

http://www.ebay.co.uk/itm/USB-Logic-Analyzer-Device-Set-USB-Cable-debug-24MHz-8CH-24MHz-for-ARM-FPGA-TE219-/301661404838

This is mine with a CLK pin



I thought this might be used in some way to trigger the recording in the software.


There are a lot of these on eBay and some show two GNDs and some show CLK and GND. Some are blatantly linking to the Saleae website for the software download and it seems the people at Saleae are pretty hacked off about it.


I have the eBy supplier for help but no reply as yet.

Peter_n

Some have +5V and GND, most have GND and GND.
Could you measure if that CLK is an really an input ?

I think they are clones. If they are, they put the Saleae brand name on a clone.

It seems there is alternative software for it :
http://sigrok.org/wiki/ARMFLY_Mini-Logic
http://sigrok.org/wiki/MCU123_Saleae_Logic_clone
http://sigrok.org/wiki/MCU123_USBee_AX_Pro_clone

Could you open the case, to see if some additions are made for the CLK input ?

Some reviews :
http://www.jwandrews.co.uk/2011/12/saleae-logic-analyser-clone-teardown-and-reprogramming/
https://unboxnbeyond.wordpress.com/2014/08/31/cheap-logic-analyzer-review-do-they-work/

The CLK input on other models can be used for the signal, but also without. In software the internal or external clock can be selected.

Links to devices with a CLK:
https://www.squirrel-labs.net/modules/programmers/usb-logic-analyzer-24m-8ch-mcu-arm-fpga-dsp-debug-tool.html
https://www.tokopedia.com/microtech-id/logic-analyzer-8ch-24mhz
The first one tells to go to the saleae download page. The second one shows a screendump of version 1.1.4.

I tried Logic 1.1.15 and 1.2.1, but can't find an external clock option.
Can you use it without CLK ?

acboother

#5
Jun 24, 2015, 06:19 pm Last Edit: Jun 24, 2015, 06:20 pm by acboother
Some have +5V and GND, most have GND and GND.
Could you measure if that CLK is an really an input ?
How do I do that?

Quote
I think they are clones. If they are, they put the Saleae brand name on a clone.

It seems there is alternative software for it :
http://sigrok.org/wiki/ARMFLY_Mini-Logic
http://sigrok.org/wiki/MCU123_Saleae_Logic_clone
http://sigrok.org/wiki/MCU123_USBee_AX_Pro_clone

Could you open the case, to see if some additions are made for the CLK input ?
Mine doesn't look like anything like any of those clones on the inside.

I don't know how to tell if any additions have been made for the CLK input. What should I do?
Quote
Some reviews :
http://www.jwandrews.co.uk/2011/12/saleae-logic-analyser-clone-teardown-and-reprogramming/
https://unboxnbeyond.wordpress.com/2014/08/31/cheap-logic-analyzer-review-do-they-work/

The CLK input on other models can be used for the signal, but also without. In software the internal or external clock can be selected.

I missed where that internal/external selection is. Can you point me towards it?
Quote
Links to devices with a CLK:
https://www.squirrel-labs.net/modules/programmers/usb-logic-analyzer-24m-8ch-mcu-arm-fpga-dsp-debug-tool.html
https://www.tokopedia.com/microtech-id/logic-analyzer-8ch-24mhz
The first one tells to go to the saleae download page. The second one shows a screendump of version 1.1.4.
I'm using the Saleae sofware.
Quote
I tried Logic 1.1.15 and 1.2.1, but can't find an external clock option.
Can you use it without CLK ?
I don't know if I can use it without the CLK feature - depends on what it does whether I will be able to utilise it in the future.

Cheers Alan

Peter_n

Try to measure the resistance between CLK to GND and +5V, for example with the device not powered.
Try a weak signal of about 2V, via a resistor of 10k when the device is powered. If the signal is 2V before and after the resistor, the input is high impedance and it is an input.

It seems that the Saleae software does not have an option for external clock.
I suppose it will work without.

acboother

Try to measure the resistance between CLK to GND and +5V, for example with the device not powered.
Try a weak signal of about 2V, via a resistor of 10k when the device is powered. If the signal is 2V before and after the resistor, the input is high impedance and it is an input.

It seems that the Saleae software does not have an option for external clock.
I suppose it will work without.
Just done a continuity test between CLK and GRD and it doesn't beep. So I guess the CLK isn't erronously a GND.

1.3v battery gives 1.2v across the resistor (is that the right place to measure?) when powered up.
 

Peter_n

#8
Jun 24, 2015, 06:42 pm Last Edit: Jun 24, 2015, 06:46 pm by Peter_n
A battery of 1.3V via a resistor to CLK causes a voltage drop over the resistor of 1.2V ?
Then it is probably a clock output.

An input should have no voltage drop over the resistor.

larryd

#9
Jun 24, 2015, 07:27 pm Last Edit: Jun 24, 2015, 07:30 pm by LarryD
Quote
This is mine with a CLK pin
In the days when a micro Processor had external memory and I/O (like a Motorola 6809) using a clock signal to strobe parallel data into a logic analyzer made sense.
With micro controllers, (with internal memory and GPIO) using the clock makes no sense as the MMIO cannot be accessed.

.

No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

acboother

A battery of 1.3V via a resistor to CLK causes a voltage drop over the resistor of 1.2V ?
Then it is probably a clock output.

An input should have no voltage drop over the resistor.

With that in mind I plugged my 'scope into the CLK and low and behold I have small, offset by 0.166v  triangular wave of about 4.4kHz peak to peak 0.1v. It doesn't change with sampling frequency.

Hmm. What could I do with that?


larryd

That is weird.

My analyser has no outputs on any pin i.e. all pins other than 0 volts are inputs.
No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

dlloyd

Quote
With that in mind I plugged my 'scope into the CLK and low and behold I have small, offset by 0.166v  triangular wave of about 4.4kHz peak to peak 0.1v. It doesn't change with sampling frequency.
It's probably a clock input. The small signal you're seeing could be just the CLK picking up other signals on the PCB.

Quote
Hmm. What could I do with that?
Scroll down on this link to "External Clocks".

acboother

It's probably a clock input. The small signal you're seeing could be just the CLK picking up other signals on the PCB.

Scroll down on this link to "External Clocks".
That link is really useful. I understand now why a clocked signal capture could be really important if the capture rate isn't fast enough to resolve different logic state changes. However it may be, for the work I'll do, this won't be a problem.

External triggering seems to be useful though as everything can happen so fast you may not capture what you are looking for or capture it and not be able to subsequently find it among the mass or collected data especially if you don't use a protocol that decodes it into something more readable.

Will try some experiments later when I get back to the workbench. Anyway I won't be buying a very expensive LA for my hobby fiddling about and I'll make this one work.

Purchased a hand held logic probe and this is also proved useful and I now have a logic probe I plug into the breadboard which I hope will perform well enough.

Cheers again for the info link, very good article.

Zapro

The CLK-pin on the Saleae clone goes through an 22R resistor and then to Pin54 which is CLKOUT/**PE1

This supplies a steady 48 MHz clock all the time, regarding of what you do in the software.

The datasheet states this:
Quote
The CLKOUT pin, which can be three-stated and inverted using
internal control bits, outputs the 50% duty cycle 8051 clock, at
the selected 8051 clock frequency: 48 MHz, 24 MHz, or 12 MHz.
So that's what is happening on the clone-board. I guess you could use the 48 MHz clock for your FPGA-board or similar and clock it in sync with the LA.

// Per.

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