Home
Help
Search
Login
Register1
General Technical Chat / Re: $20,000 dollars of software or licences on a thumbdrive ?
« Last post by shapirus on Today at 10:44:01 am »This is why non-FOSS licensing sucks.
Recent Posts
2
Repair / Re: Keithley 2400 locks up when buttons are pressed
« Last post by tomn on Today at 10:38:55 am »Thanks for the reply.
Not yet, I'll try today. I'm a bit wary of losing RS-232 access (still need to get a GPIB adapter), but I think SYST:MEM:INIT should keep the settings the same...
Yeah, I forgot to mention, i did re-seat them. As the self-test always passes i doubt this is the problem, but i can give them another go.
Ah, i did not know this was a thing, thanks!
There's only one or two that could be a problem for this (on the digital 5v supply). They seems fine, and the supply seems quiet. Maybe if I get really desperate I'll consider making an offering :)
did you try the steps as outlined in chapter "Battery Replacement" of the service manual, especially the ":SYST:MEM:INIT" sequence?
Not yet, I'll try today. I'm a bit wary of losing RS-232 access (still need to get a GPIB adapter), but I think SYST:MEM:INIT should keep the settings the same...
also, i wouldn't trust the EEPROM sockets on the digital board too much, you could pull and give them a "deoxit & re-seat" treatment.
Yeah, I forgot to mention, i did re-seat them. As the self-test always passes i doubt this is the problem, but i can give them another go.
as for the key pads, a key pad repair kit for tv remotes will do the trick. iirc, the stuff i used was "gumki do pilotów" by TermoPasty.pl from a*n. i glued the new pads right on top of the button stakes without even removing the old pads, using a drop of high temperature silicone (instead of the silicone that was supplied in the kit) and letting them cure for 24 hrs. button feel is slightly "stiffer" now, but key responsiveness works like a charm since 3 years now.
Ah, i did not know this was a thing, thanks!
edit: forgot to mention: you may want to check the electrolytic caps :horse:
There's only one or two that could be a problem for this (on the digital 5v supply). They seems fine, and the supply seems quiet. Maybe if I get really desperate I'll consider making an offering :)
3
Microcontrollers / Re: ELM327 (serial to OBDII CANbus converter) discontinued
« Last post by elektryk on Today at 10:36:52 am »Nothing magic about OBD. It's just CANBus.
Or KWP2000 fast.
Or KWP2000 slow.
Or ISO9141-2 (K-line, older stuff).
Or SAE J1850 VPW.
Or SAE J1850 PWM .
OBD2 is not "just CANBus".
That's not really a problem to use MCU with CAN when you want to interface with a single CAR but it may be if you want to make an universal tool.
K-line BTW can be implemented with UART and proper transceiver.
4
Buy/Sell/Wanted / Re: FS [CAN] : HP 8503A S-parameter test set
« Last post by entegreci on Today at 10:35:01 am »Hello, this is Necati UNAL from Turkey. I am interested in this device. Is it still for sale? Please Information. Thank you
5
Test Equipment / Re: SDS800X HD Bug Reports + Firmware
« Last post by ebastler on Today at 10:34:17 am »I found a bug:
When adjusting the level for source A in "trigger delay", and setting it below low level of signal, acquire stops. At 50% level it triggers kind of slow, but below the rate increases, but then eventually stops completely. The trigger does not restart after moving it back.
I looked at this again, and tried to reproduce it with simplified signals (just two square waves). All I can see, in my experiments and in your video, is:
- If you drop the CH3 threshold below the CH3 signal swing, there are no valid transitions in Source A anymore. Hence no triggering; that's to be expected.
- As you raise the CH3 threshold higher and higher, the low-to-high transition in CH3 will be detected later and later. Eventually it will no longer occur before the CH1 transition, but afterwards. And the next transition in CH1 is well outside the time window you have set for the delay trigger condition. Hence no triggering; that seems correct too.
6
Projects, Designs, and Technical Stuff / Re: Simple illuminated time display that can be driven over USB?
« Last post by xvr on Today at 10:33:16 am »> $130? For a tiny, monochrome 128×64 display?
This is not only display. This is complete HMI (Human Machine Interface) module. But $130 a little out of bounds
Here https://nextion.aliexpress.com/store/4579011 will be cheaper (and better)
This is not only display. This is complete HMI (Human Machine Interface) module. But $130 a little out of bounds
Here https://nextion.aliexpress.com/store/4579011 will be cheaper (and better)
7
General Technical Chat / Re: $20,000 dollars of software or licences on a thumbdrive ?
« Last post by Psi on Today at 10:30:45 am »A dead license dongle can usually be replaced for a small fee once you return the dead one.
But a lost dongle often results in having to fork out the full cost of a new license (or use insurance).
Mainly because if that was not the case, you could give it to a friend, say you lost it and get a cheap replacement and your friend could use the software for free as long as they stay offline so the lost dongle S/N never gets deactivate in an update.
But a lost dongle often results in having to fork out the full cost of a new license (or use insurance).
Mainly because if that was not the case, you could give it to a friend, say you lost it and get a cheap replacement and your friend could use the software for free as long as they stay offline so the lost dongle S/N never gets deactivate in an update.
8
Other Equipment & Products / Re: Dymo 550 Thermal Printer DRM Hacking
« Last post by js_12345678_55AA on Today at 10:29:50 am »@oztek
The IC printing "STM32..." looks genuine... But who knows ;-)
Please attach a screen shot of the STLink Utility program after you programed the IC (to have a look at base address, ...)
JS
The IC printing "STM32..." looks genuine... But who knows ;-)
Please attach a screen shot of the STLink Utility program after you programed the IC (to have a look at base address, ...)
JS
9
Beginners / Re: Power supply multi-rail noise separation?
« Last post by paulca on Today at 10:14:37 am »So... in the meantime (until I redesign a whole board) I have the battery and I have loads... and I have protoboard.
First test shows without filters of any kind, save an LM7815 regulator, the battery powers the current 16V single supply headphone amp... silently. Of interest, it's also silent when connected to the rest of the apparatus. Confirming the noise I am annoyed with is coming from/caused by/influenced by the power supply.
Next I need to see if I can power the digital audio box (STM32H7 based) from a separate LM7824. It has it's own buck module capable of 24V and I don't want to drop too much linearly if I can avoid it. The box pulls 200mA ish.
I might not need any filtering... I doubt it though. Something is going to pull all that USB ground garbage into the audio somewhere, I just know it.
Does this look sane?
The right hand side I'm fine with, even without a darlington it will work. It's only temporarily / testing.
On the CLC/PI filter. I'm out of my depth. If a capacitor multiplier is a "High school" level thing, inductors are definitely one level higher up from where I am. I can't seem to get a straight answer it's always a cyclic this depends on that, which depends on that which depends on the original thing. It seems to make sense of this, mathematically, we get into greek and I go blank.
It's not just impedence at a rising frequency, it's proper understanding on the impedence of the L and both Cs and how they interact.... with the variable load R throw in. If you can get it to attenuate rising frequencies from as low as you dare, you are also likely to have to deal with the resoance of some random (calculable) higher frequency.
It's beyond me
I feel religated to stealing an example and YOLO or buying some cheap AliExpress module and hopeing it's worth bothering.
I'm presently looking for examples to pillage instead.
First test shows without filters of any kind, save an LM7815 regulator, the battery powers the current 16V single supply headphone amp... silently. Of interest, it's also silent when connected to the rest of the apparatus. Confirming the noise I am annoyed with is coming from/caused by/influenced by the power supply.
Next I need to see if I can power the digital audio box (STM32H7 based) from a separate LM7824. It has it's own buck module capable of 24V and I don't want to drop too much linearly if I can avoid it. The box pulls 200mA ish.
I might not need any filtering... I doubt it though. Something is going to pull all that USB ground garbage into the audio somewhere, I just know it.
Does this look sane?
The right hand side I'm fine with, even without a darlington it will work. It's only temporarily / testing.
On the CLC/PI filter. I'm out of my depth. If a capacitor multiplier is a "High school" level thing, inductors are definitely one level higher up from where I am. I can't seem to get a straight answer it's always a cyclic this depends on that, which depends on that which depends on the original thing. It seems to make sense of this, mathematically, we get into greek and I go blank.
It's not just impedence at a rising frequency, it's proper understanding on the impedence of the L and both Cs and how they interact.... with the variable load R throw in. If you can get it to attenuate rising frequencies from as low as you dare, you are also likely to have to deal with the resoance of some random (calculable) higher frequency.
It's beyond me
I feel religated to stealing an example and YOLO or buying some cheap AliExpress module and hopeing it's worth bothering.I'm presently looking for examples to pillage instead.
10
Test Equipment / Re: Vevor SDS1104 for first oscilloscope?
« Last post by Aldo22 on Today at 10:11:23 am »I don't know if it's "problematic", some time ago even "good" brands had 2.5k, but there are better options today for little money.Max Record Length: 20K is a bit low these days.How problematic is the max record length?
Since I'm currently experimenting with something like this, I'll show you with my $130 Hantek.
In the first picture there is a 20KHz sine wave at 10us/div, with a 50ns pulse every second (1Hz).
If you trigger on the pulse, a thin line appears in the middle. But there is nothing else to say about how the pulse looks. (1st picture).
If you stop it there and zoom in it to 50ns by turning s/div, you will see a very rudimentary pulse with 4k (2nd image). It doesn't say much about the shape of the pulse.
But if you stop it with 8M (record length), you can see much better in the magnification what is going on with the pulse (3rd image).
The more record length, the more accurate the magnification. Just like the resolution of a digital photo.
That is one difference. The experts here can probably explain this better, as I am also a beginner.
Btw. This is for illustration purposes only and is not intended to be an recommendation for the Hantek. It does not have 4 channels.