Recent Posts

31

General Technical Chat / Re: Is LinkedIn worth keeping?

« Last post by tom66 on Today at 09:08:14 pm »

I must be living in a backwater. Why is contacting you at work - by a headhunter - dumb? How else are they supposed to contact you@your_work since I'm pretty sure you wouldn't splash your private phone number and email all over the interwebs (and if you did, probably not link them to your CV). Worst case, surely, is they get blocked by your company but there's a chance you may follow up, which is all they're after in the end.

Well, he didn't leave a phone number, so was expecting an email response, from my work email, about a competing job?

No, I am not going to do that.  Unprofessional to use your employer's computer systems to search for other jobs (and potentially a breach of contract) for one. 

32

Beginners / Re: Fast PWM IC

« Last post by Zero999 on Today at 09:07:09 pm »

I still don't understand why you need 100MHz PWM.

The problem is, it needs to be able to generate much higher frequency harmonics. 10% duty cycle has a 1ns on time, so you need much sharper rise and fall times, say 100ps, so you need a slew-rate of 33GV/s for a 3.3V signal.

33

Computers / Re: Format a 256GB pendrive with FAT32 using a windows 10 pc

« Last post by IanB on Today at 09:05:06 pm »

It's often overlooked that the Windows GUI is a graphical shell sitting on top of a command line OS. Many more advanced options are often found if you bypass the graphical shell and go straight to the underlying tools.

34

Projects, Designs, and Technical Stuff / Re: (Yet Another) DIY Multislope ADC

« Last post by iMo on Today at 09:04:07 pm »

NNNI may test that easily (including the new rundown) while running off the stock 12MHz crystal against the PLL version. A stable canned XO/TCXO would be even better. The 48MHz is needed, however, as you want to upload the binary to the 2040 easily, and you will do it many times, sure.

On the other hand I would be much more concerned about the noise around the comparator and auxADC.. That introduces errors and I would be happy to see some real data coming off the above code, such we may play with the math. Perhaps NNNI finds some free time for running it on his pcb, its just a copy/paste exercise..

35

Projects, Designs, and Technical Stuff / Re: Accurate sine wave in terms of amplitude

« Last post by PCB.Wiz on Today at 09:03:35 pm »

The frequency can be between 1-10kHz.
 Amplitude can be between 200mV and 5V. I don't know how much THD (or any other parameter) affects to the device.

Do you need to adjust this generator across 1-10kHz and 200mV-5V ?

I don't know how much THD (or any other parameter) affects to the device. I need to finish the design, build the device and test. And then probably, re-design the circuit, build another device and test again. Maybe at this point I actually know all the key parameters, including if THD matters or not.

Then you are probably best to get a simple, low cost MCU based DDS function generator module from AliExpress, that can easily and quickly cover your range while you determine what you really do need.

36

Repair / Re: Repairing TDS5000B acquisition board

« Last post by gianrisa on Today at 09:03:19 pm »

@smaultre were you been able to fix it especially the error 351 ?

37

General Technical Chat / Keychain bling, solder failure

« Last post by joeqsmith on Today at 09:02:11 pm »

I cut out some brass to make a custom keychain using an FPGA that I had used.   These were well over $1000 back then and I had reballed this part twice before scrapping it.    It's looking pretty rough now.

https://www.ebay.com/itm/223223126383

38

Dodgy Technology / Re: 10ah 18650 cells

« Last post by Zenith on Today at 09:00:26 pm »

I bought half a dozen 18650 cells on AliExpress back in the day - 5 years or so back. They were quite cheap. The sellers had good feedback and they appeared to be, according to my charger/analyzer, perfectly good Panasonic 18650 cells. I'm still using them in flashlights.

There were a few suppliers on ebay, who seemed to know what they were selling, and didn't sell 10,000 mAh obvious rubbish. They tested what they were selling and didn't sell tat. I believe ebay got the wind up over the dangers of Li-ion cells, which they they thought were all 18650s and stopped 18650s being sold on their site, although other Li-ion cells could be sold. I haven't looked recently.

These days, if I wanted more, I'd enter "buy 18650 UK" into Google and pick a reputable looking supplier, of which there appear to be several. You can probably buy then from Farnell etc, in which case they are unlikely to be junk.

39

Microcontrollers / Re: Has anyone used ASAN & MSAN, and relevance to embedded arm32

« Last post by __george__ on Today at 08:56:14 pm »

There is also puncover: https://github.com/HBehrens/puncover which can help you to analyze the stack usage statically (also integrated with  Zephyr/west). Apart from that I never tried ASAN/MSAN with embedded, from what I have heard around it is too much overhead for most use cases.

40

Projects, Designs, and Technical Stuff / Re: Accurate sine wave in terms of amplitude

« Last post by IanB on Today at 08:55:54 pm »

Or I simply don't know yet. Pretty much all the requirements (=the rest of the circuit) depend on what kind of signal I can generate. The frequency can be between 1-10kHz. Amplitude can be between 200mV and 5V. I don't know how much THD (or any other parameter) affects to the device. I need to finish the design, build the device and test. And then probably, re-design the circuit, build another device and test again. Maybe at this point I actually know all the key parameters, including if THD matters or not.

Ah. Seems familiar. Do you develop software by any chance?