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- Опубликовано: 28 авг 2024
- Episode 992
I have a final PCB revision and firmware. The counter operates to 1 GHz and incudes a calibration routine that stores the cal data in EEPROM. The project is here: www.pcbway.com...
Firmware available at: github.com/ims...
Be a Patron: / imsaiguy
Nice project. The frequency division shouldn't be non-linear. Prescalers can't make that kind of error. The cal errors just come from rounding at that low frequency. That should be resolved in software - maybe some averaging during the cal procedure. But that's all just detail - great project.
My prescalers finally arrived this week. Looking forward to playing with them this weekend.
Thanks for sharing, got my prescalers in mailbox already and will now be making a simillar unit soon 🙂
Nice neat PCB.
Merry Christmas and a Happy New Year.
Nicely done. I’ll need to look at your code to see how those OLED are used.
Maybe put a TCXO on there, within an additional prescaler, to use as a time base.
I've learned some since I started watching your videos. I appreciate how much time you had for these projects during COVID.
I've started wanting a higher frequency counter, but I'm holding out for more precision. My tinies and HP8561 do the GHz counting so far.
Is there a record for most consecutive posts? I respect that you might be going for it!
Thank you.
A counter shouldn't need calibration if the reference clock is accurate and the logic is not skipping or double counting the input pulses. The Arduino is not a good choice for a counter without some external logic help. The main clock oscillator is not accurate nor stable and the timer is limited to < 50 percent of the clock frequency. I don't believe there is a way to get a true 1 second gate from the 16mhz clock with the internal counters. Possibly one could use other than a 1 second gate and calculate the actual frequency by a scaling factor. I noticed they were also using floating point numbers int the FreqCount library, not a good thing. One improvement would be to add some external gate logic to make an accurate .1, 1 and 10 second gate from a quality 10Mhz oscillator. The arduino would arm the gate logic which would then start counting input pulses. When the 1 second gate generator went false it would interrupt the arduino and the code would do what ever necessary to the accumulated count. You are still limited to
In one of your videos you mentioned having the nano frequency counter write the frequency to a memory and then having the other nano read from that memory. Take a look at the PCA9641 by NXP 2-to-1 I2C master demultiplexer with an arbiter function. That would solve your problem with a $3.20 part.
Nice work.. Just a couple of advices from PCB design perspective to get better precision and avoid possible noise.
a) Avoid using chip sockets if not totally necessary. Especially for prescaler. Soldier directly to PCB.
b) Nano's ICMP pins are too close to tic tac buttons. Causes finger inconvenience, unnecessary feel.
c) Have input socket as close as possible to Prescaler, and Prescaler to Nano.
d) Have LCD Display and buttons on one side of PCB and other components on the other side for more professional look and better boxing purposes.
d.1) Having nano and prescaler one one side of PCB would also allow you a chance to cover those with any metallic enclosure (even with cheap aliminum folio) to eliminate outside interference.
Optionally, you could drop tic tac button(s) all together. Say, in your code, check if any (meaningful) signal present on inputs in the first 10 seconds of Nano boot (at the end of setup section), if so, use for calibration purposes, or, after 10 (or, n seconds) resume regular operation.
Cheers,.
you must have some nice boards. do you have a share site?
A word of warning on the OLED displays. When buying one, check the pinout order of the display against the PCB layout. Not all boards have the same pinout.
Please make an arduino tx tone decoder like ctcss and dcs
Imasiguy? Who is that :~D (Time to update the splash screen)
I noticed it as well .....
@@egbertgroot2737 I thought my eyes were playing tricks and had to do a quick rewind!
@@TheOwlman I hit the left arrow immediately as well .... Imsaiguy never seizes to amaze me. A good thing ;-)
Does anyone have any spare of these boards. I want to buy one.
Your splash-screen says "Imasi Guy", probably due to software copyrights.
yes 😎
LOL you are using the wrong resolution for the display, this is a flaw in the lib.please change for better font display
pin D5 of Arduino is not defined.....how can Arduino read frequency? I think this software will not work with SAB6456A Prescaler
it is I2C and is handled by that driver, no need to define
@@IMSAIGuy ok thanks to reply
can u provide ur mail address?
@@mohsinsiddique2486 I get many requests for mentoring or help with their work or personal projects. I do not have time to help everyone. I try to answer questions the best I can. It is best to ask questions in the comment section of my videos, that way others can help also.
I have bought 10pc Sab6456A but 9 of them does not oscillate . Had u faced same problem? The is labeled NXP.
PCB Way is really gett'n so popular on youtube!! & they do nice work!! wow! up to 1Ghz!! nice!! if U have a counter on a oscilloscope U could copy that! or examine the code setup,to check a 2nd opinion. on the data+ processing!! I don't understand where the ''flake'' could be in the system? shouldn't be the arduino....not 2 sound like a nagging pain!!
I'm not sure I understand why the cal should be frequency dependent? Is the counter missing some counts at higher frequency? If so, could it perhaps be a software issue?
It only calibrates at a single frequency
its the clock on the arduino (that all this refereences to) that may drift a bit with temperature, i suppose
The division was based on the arduino's oscillator,which isn't well controlled. But the project itself is cool. Thank you for sharing!
@@gominosensei2008 but if that is the reason, there would be no benefit to frequency dependent calibration.
I agree, the Arduino crystal or (ceramic resonator) is not going to be all that accurate and would need to be calibrated but once calibrated at one frequency it should remain calibrated for all inputs. However there is a lot going on under the covers with the Arduino libraries which may be causing lost counts. Also the timer timer input is only rated at to 1/2 the processor clock rate undefined what happens above this. If you do the math on how millis() is generated it works out to 1.024 ms per count. The mills() timer (8 bit) is fed 16MHz prescaled by 64 or 250KHz divide this by the 256 counts for the 8 bit timer and you get 976.56 Hz or 1.024ms per count. To correct the issue the millis library adjusts the count about every 40 some counts by skipping a count ... 39, 40,41,33 ...
If I order the board, will it be Rev A?
yes
@@IMSAIGuy - Thanks!
Interesting project. I was going to take a closer look at the schematic, but it apparently will only open with Eagle, which is now owned by Autodesk, and is subscription-based?? No thanks. How about a PDF or KCAD file?
there is a printout in the description on the PCBWAY
I added a pdf
@@IMSAIGuy Thanks. I wasn't having much luck getting the one on PCBWAY to enlarge enough to see it on the screen.
I like the project. I like the work you've done.. Now Please spend more time learning how to record. Stop all the moving around and all the hand waving.. have a script of what your going to say and do a dry run thru BEFORE you record.. I don't want to be that guy but the way you have recorded makes it very hard to follow what you are saying and what you have done.
You have the electronic skills, that's easy to see... spend just a little more time working on the youtube piece and you will get more sub's and likes.. Good luck
In my opinion, your conversational style is one of the charms of your channel. Don’t change.