Hobby Components USB 8CH 24MHz Logic Analyser (HCTEST0006)

[Armac44]

The Input circuit is an HC245 but it is powered from 3.3 V not 5V. The input circuit has 100 ohm resistors in series with each input and 100K bias resistors between each 245 input and 3.3 V. I presume they are there to stop open circuit inputs from damaging the 245. The 100 ohm resistors would appear to limit the input current when the input goes above 3.3V or bellow 0V. The data sheet gives 20 mA as the absolute max, so this gives an input range of about -2V to 5.3V, possibly a little wider since the forward drop of the substrate diodes is ignored. However the device will take current, limited by the 100 ohm resistors from the input circuit if the input goes outside the 0V to 3.3V range, which is likely to affect the circuit under test. The analysis mentioned in http://www.jwandrews.co.uk/2011/12/sale ... ogramming/ is relevant, though the circuit there did not apparently have input resistors. The idea of replacing the HC245 with an LCX245 seems good - but not easy to do. The thresholds will be slightly affected by the resistors. I am interested in all this because I want to look at some RS-232 circuits - but think now that the analyser will affect the circuit too much to be useful.

[andrew]

I see the post where you have taken your comments from. I'm assuming it's been done in this way so that the transceiver can work both 3.3V and 5V logic levels. The 100R resistors are clearly there for this purpose acting as a current protection when interfacing to levels above 3.3V. Depending on what levels your RS232 circuits use it may not have been suitable for this purpose anyway as it wasn't designed to interface to RS232. I'm going to make a small edit to my previous post as I can confirm now that the transceiver is powered from 3.3V.

[Salts]

Just to confirm this device works with sigrok http://sigrok.org/wiki/Main_Page which is "a portable, cross-platform, Free/Libre/Open-Source signal analysis software suite"

The system I used was an old HP elitebook 2530p running linux lite which is built off Ubuntu 14.04 LTS

[pirlouwi]

I saw that Saleae software is able to display analog traces.
Is there a chance for HobbyComponents logic analyser to produce such analog traces instead of the digital ones, via a firmware change for example?
Any pending work concerning this feature?

[andrew]

The analyser just uses and 'off the shelf' cypress microcontroller (CY7C68013A). Unfortunately this device doesn't appear to have any built in capability to read analogue signals so it is very unlikely that this particular device will ever include that capability.

Just for extra information:

As some Sarlea analysers use the same chip, this is why this product can be made to work with their software. However you may be interested in this freely available piece of software that doesn't require a licence:

http://sigrok.org/

[KenMacfarlane]

p.s. the links to the drivers don't work unless you are logged in!

[andrew]

We do require you to be logged in to download any files hosted by this forum. Unfortunately this has become necessary due to very high bandwidth usage caused by sellers from places like eBay directly linking to our files. It is for this same reason that we have to watermark all our pictures. Accounts are free to create and do give you access to a lot of content.

[MartynHill]

Hi everyone

Having just purchased one of these little devices, I am struggling to get my XP laptop to recognise the USB device.

I have downloaded the fx2lafw driver ZIP file from this site, but my (Symantec) AV immediately detects the "installer_x86.exe" file as a virus and quarantine's it!

Pointing Windows device installer directly to the inf file itself fails also.

I also note that the USB Vendor/Product IDs in the inf files do not match the device itself:

INF: VID_04B4&PID_8613
Actual device: VID_0925&PID_3881

I then downloaded the driver package directly from Cypress and followed their instructions to modify/add the correct VID/PID in their INF file, and get a little further, but their driver is again failed to be recognised.

Has anyone else hit this?

Do we know how to rectify the failed driver install?

Thanks in advance!

Martyn Hill
London

[andrew]

I have downloaded the fx2lafw driver ZIP file from this site, but my (Symantec) AV immediately detects the "installer_x86.exe" file as a virus and quarantine's it!

The files should defiantly be clean. We actually created them ourselves and they have been scanned by over 40 different antivirus scanners including Symatec. I would suspect that it's probably just your scanner reporting a false positive.

I also note that the USB Vendor/Product IDs in the inf files do not match the device itself:

We flash the analyser with firmware and it should also have been programmed with a VID of 04B4 and PID of 8613. If it has anything else then something is defiantly wrong. Can you send an email to support (at) hobbycomponents.com and we will try and remotely fix it or failing that send you a replacement.

[MartynHill]

Hi Andrew

Thank you for such a swift response!

The VID/PID flashed on my unit are definitely not what the drivers are expecting by default (i.e. not VID 04B4 & PID 8613) - they appear to be the same as the clone-unit that is discussed in JWAndrews post (0925/3881 - referenced earlier in this thread).

Possibly mis-flashed or faulty EEPROM?

Interestingly, after a lot of messing about, I finally got Windows to accept the (modified) CyUSB3.sys/inf - but starting PulseView still showed no valid device. After another reboot, Windows again fails to recognise the device, asking for the drivers...

I'll send an email as suggested - thanks!

M.