A PIC based frequency counter kit - part 1:building and modifying
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- čas přidán 27. 08. 2024
- This video is about building and modifying a PIC frequency counter and crystal tester in kit form sold on the internet under many names, for example "1Hz-50MHz Digital LED DIY Kits Crystal Oscillator Frequency Counter Tester"
Part 1 describes how to modify the unused crystal testing part of the circuit into a pre-amplifier for the frequency input. I am also briefly touching on some firmware issues which are further investigated and fixed in part 2. • A PIC based frequency ...
The kits on the internet "forget" to mention that the original counter circuit and firmware were developed by Wolfgang "Wolf" Büscher, DL4YHF
www.qsl.net/dl4...
I bought two of these counters to use them on my radios. No one worked at the beginning , but after seeing and modifying what you show in this useful video description everything started to function beautifully. Thank you very much.
Yes, the counters are great but whoever added the weird crystal testing circuit to it has a lot to answer ... Glad you got yours to work now.
You would need a high power transmitter, just about, to work with the original circuit without the pre amp !
I have 2 kits as well, so will try to convert!
Another big THANK YOU for posting this. I had mine unmodified for a while and only checked with a crystal when i built it, but could never get it working correctly with my Leader 17A Signal gen. After doing your mod it is now working perfectly and i'm looking forwards to using it for some old Tube Radio alignments. Thanks!!
After connecting external power to the programming socket I was finally able to erase the "bad" 16F628A and program it with your improved version and guess what.... IT WORKS!! That certainly was a long and painful process to get any of this stuff to work, you'd think someone would have debugged this stuff before, it's like nobody has ever tried any of it except you and I!
I agree that Microchip is making the process very obscure and unnecessarily hard. I am glad it worked for you now. I used the breadboard method while developing the firmware since you can also debug (of sorts, mainly measuring timing). I am now actually using the same setup as you have shown and just posted how to use it without external power.
Once you got everything working you'll find the little counter is very accurate and with my latest firmware and the count mode, if you feed it with a 1Khz signal you have a stopwatch of 99 seconds with 1ms resolution. Interesting for all sorts of experiments.
A lot of thanks, comerade! Your construction is nice, repeatable and stable. Thank you for detailed description, it was very useful.
Thanks sooooo much! I did the mod. I am learning a Lot from your videos. Tnx agn!
Hello Heinz! I am nearing completion of your Frequency Counter Project. There are only a few matters to conclude.
I came up with a few tricks of my own… Firstly, I used 1206 SMD components for the pre-amp. They can be worked in between the existing pins of the involved component footprints, on the PCB. They fit nicely. And, using them completely avoids all of the possible height issues that might arise from bodging vertical through-hole components on the diagonal.
Secondly, it occurred to me that mounting all of the components on the back of the PCB would avoid any other unseen height issues and be much more convenient for access, once the device is mounted in a case.
Only the number display and those components whose pins would not invert remain on the front of the PCB. These additional items include the MCU, of course. I am using the power jack; it will not invert, so it, too. Maybe a couple of more things that I am still think on…
Thirdly, to prevent slipping with the razor knife while cutting the various tracks, I secured a metal straightedge to the PCB with Blu-Tack poster putty. I also tacked down the entire PCB, to keep it from moving. (Blue painter's tape would do nicely, too. Both release cleanly.) This made for straight cuts and prevented a wandering blade, both being especially important for cutting the extremely short trace at R1/330R. This enabled me to make cuts so small that they are not apparent to the naked eye, at all.
Finally, I am researching what is needed in the way of a wall wart power supply. As a MCU is involved, a transformer type is indicated.
The board silkscreen specifies a 9 volt supply. The MCU is only using 5 volts, if I recall correctly. Does the display need the higher voltage? Or, might a lower voltage wart be used to conserve power and avoid unnecessary voltage regulator heat? I have a 7.5 volt wart that might do, if the whole 9 volts are not needed.
So, I am having fun and I have you to thank for that, so thank you!
Sounds like a great project. I agree that transfer of components to the rear would make mounting the display easier but I managed to keep everything below or at display height so it wasn't necessary for me. The push-button can be replaced by a panel mounted version and I never used the barrel connector for power anyway. With respect to your question, the 5V output from the regulator is used for everything, including the display. The only exception is the crystal testing circuit. 7.5V DC (!) will be fine
You can solder the top two resistors (of the 3 per the mod) on the bottom instead, then bend over the lowest/3rd one.
BTW, you don’t have to clip off the lead of the 3rd resistor for the preamp input side, for convenient connect for the input.
Nice work .. I built the preamp mod as shown. Works exactly as yours.
Thanks ✌️
Congratulation for this excelent and very good explanation,
Alter I finished installing two of these frequency counters I bought another one to be added in an RF Generador. This time I didn’t modify the board. I’ve just added a small pre-punched PCB board where I mounted the pre-amplifier needed to drive the counter.
As shown in the following diagram transistor 2N2222 is used, it has been tested working in a wide range from KHz to 50 MHz.
Sorry I couldn't include the diagram in this message, but it consist of 4 resistors , 1 transistor,
and 1 capacitor.
Exactly. These kits are fantastic for trying out your own mods and improvements. Looks you have a great design there.
excellent - this will save me a lot of head scratching. Thanks very much.
Hi there and thanks for your tutorial.
My goal was to measure a square shaped signal (it is a bit rounded though) around 20 MHz. This signal has an offset.
Its minimum voltage is at zero volts, while its maximum voltage can vary between 1 to 2 volts (depending on my setup).
Before watching your video, I tested the counter and it had trouble measuring this signal. It just showed zero.
I must say that the counter was able to measure another source of 25 MHz signal (the one that has an amplitude of 6 volts and also has a minimum voltage at zero).
After your upgrade, the behavior of the counter did not change.
I noticed that when I connect my signal to the preamplifier input, then I see that the whole signal is shifted up by 2.5 volts, so if it was say 0-1.5[V], now it becomes 2.5-4[V].
And of course I don't see the measurement result on the screen.
I read here in the comments, you wrote that the populated capacitor's purpose is to remove and DC offset.
While in my case, I am not sure whether I want this or not?
Since I don't have a signal generator yet, it's hard for me to test a variety of frequencies and shapes and see how they affect the counter.
But what is important to me is that the counter will be able to measure exactly my customized signal.
Can you please help me?
The PIC input is a Schmitt-Trigger. The datasheet says for seeing a 0, the voltage should be between 0 and 0.2*VDD for a 1, the voltage should be between 0.8*VDD and VDD. With VDD =5V that means the signal at the PIC's input needs to go below 1V and go above 4V to be reliably detected. A signal with an amplitude swing going only between 0 and 2V cannot be measured without a pre-amp. I am not sure what capacitor you are referring to. If you built the crystal tester, it needs a 1nF cap (marked 102 on the board) to keep the DC from the PICs input. The pre-amp has another cap of 470nF in the input to block external DC voltages. It should work with that. If you want, you can swap the 330 ohm resistor and 470nF. That allows you to leave the cap outside as a flying wiring and try it with or without the cap. Finally also notice that besides signal strength and frequency, the original software has issues if the duty cycle of the signal is far off the symmetric 50% case. My last video in the series on this frequency counter explains it.
thank you! found this video and it saves me a lot of time.
Hello, Heinz. On the front of the board, notice that there is a ground trace coming from the side pin of the barrel power jack to the auxiliary inputs that you are using. (You jumped this trace to the center ground pin.) I am using the barrel jack to source power, so I do not need this track. That is, I am not using the power and ground pins, of the four pin set on the front of the board.
I am using the two signal pins (IN and G,) of course. Notice that G has an independent connection to ground on the back of the board. This means that, for me, the front power grounding trace might be repurposed for other uses.
The R1 pre-amp input pin sits just above this ground trace. I am considering cutting the trace and using the portion that goes to the four pin header. R1 could easily be solder-bridged to this new, short trace.
This would group all of my external pins at the four pin header (I am only using three of these pins.) This would make for a more organized, single, multi-wire connector.
I do not think the bodge is much worth the effort, because the PCB will sit in a case and mostly permanent wires will go from these functions to jacks on the face of the case. Who cares if, once in a great while, you have to disconnect two wires connectors, instead of just one, to get the PCB out of the case to make a repair. But, it is a consideration, for the purpose of a single wire connector, and points out the availability of this trace for other uses, for people that are not using it as intended.
I did not have a convenient attachment point for the pre-amp pin at R1, because I used SMD resistors and they covered the pin hole. So, I did use the ground trace to carry the pre-amp pin signal over to the four pin connector. This worked well. I was able to use a multi-pin connector to make a single connector block for the wiring pigtail.
I have finished everything except the case. My frequency generator only goes to 2MHz, so that is as high as I could test. Both inputs function as expected. The pre-amp allowed me to reduce my frequency generator output to its lowest setting and I still had a steady count.
Thank you, Heinz, for sharing this great project. How about a frequency generator project?
Glad your project is coming along nicely. As for frequency generators, there are so many on the market already. I am very happy with the FY6600 from the functions it offers and it goes to 50 MHz I believe. The trouble with it is its terrible cheap switch mode power supply that leaks high voltage into the outputs. I made several videos about my attempts in solving this issue. I am glad it is fixed now and with the new power supply, this amazing generator (actual two generators for the price of one + a frequency counter) is my main source of frequencies of any wave form (30-odd preset + you can edit your own), AM and FM modulated HF, sweeps, bursts etc. I don't think you could built your own generator with remotely similar capabilities for the price.
@@TheHWcave SDG has done major mode videos, for this unit, including the power supply issue.
czcams.com/users/sdgelectronicsvideos
Was there a reason for changing from 470pf to 470nf on the input side of EI9GQ's circuit? A mistake?
This is excellent. Thank you :-)
instaBlaster.
I have one of these and wanted to use it as a display for a signal generator. It seems to work pretty well as you have indicated. Your firmware improvements are most worthwhile and must have taken some time to implement (I have looked at the original code myself and can confirm that its a bit of a mess!). One thing I wanted to do was to dispense with the flashing decimal point which is used to distinguish between kHz and MHz and use two leds on my front panel to indicate either MHz or kHz. I'm not sure this is possible however with a 5 digit display as there are no available output pins left on the PIC. If you or anyone else has any suggestions how this could be implemented I would be interested to hear!
I don’t think decoding the 7-segment decimal point with some external logic to derive a signal that can drive external range indicator LEDs is a good solution. The multiplexing will make this very tricky and, worse, the multiplexing frequency is not 100% constant but changes slightly (see the explanation of “dark time” in my latest video on this when using the kit as an count-up counter).
I think your best options are to derive your external range LEDs from the range switch of the generator. If that is not possible, the easiest way to make use of the LEDs would be to design a little circuit that is hooked (in parallel to the counter) to the TTL output of the signal generator and simply detects if the frequency is above or below certain values. There are many ways to do that. The old-fashioned way for example would use the two retriggerable monoflops in a 74123 to detect if a frequency is above or below a certain value (with an accuracy depending on how close you can get your RC timing to the desired frequency). The pragmatic and cheapest way is to get an Arduino Nano clone to do the job. A simple frequency measuring routine followed by a few if’s to drive the outputs connected to the LEDs. If all you need is a >= 1KHz and >= 1MHz then even at higher frequencies, say 30 MHz the Arduino Nano should be ok because it doesn’t need to measure the exact value, only that it is more than 1 MHz
@@TheHWcave Good suggestion. I will have a go at implementing your idea in one of my future builds. Thanks very much for your reply.
Hi there. Could somebody please explain why the Crystal tester is "useless"? I have many other ways of measuring signal frequencies, however I bought the (yellow PCB) kit specifically to measure and sort crystals quickly. What is the problem here, and/or is there a better (simple) way to measure them?
I kept trying all sort of preamplifiers in order to use it together with a regenerative receiver using a pick up coil. No luck at all. I run out of solutions... maybe you can help me with an idea ))
I'm doing a similar project. I'm trying to pick up enough stay IF oscillator signal to trigger my old Ramsey Electronics freq counter. I did succeed by using a 2.5 mH RF choke as a pick-up coil attached to a short length of coax and plugged directly into the BNC input of the freq counter. I did find it necessary to connect the freq counter ground to the chassis ground of my receiver. My receiver is an old tube type. I wrapped the pickup coil in masking tape to prevent shorts and then placed the pickup at the base of the IF mixer tube socket and it worked. So try a big honkin' 2.5 mH RF choke.
@@livesonjura Ahaaaaa... Now that is one thing I haven't tried yet. Thank you Richard. It does makes sense.. as with that inductance it should be able to pick up a lot of signal )) I will do that right away. 73
@@dxexplorer The PIC has a normal Schnitt-Trigger input so a couple of volts are needed to drive it reliably. If it helps, the original design was for displaying the tuned freq. of a radio by picking up the much lower and way stronger IF oscillator freq and let the PIC do the adding of the necessary offset. This capability was in the original firmware but I had to eliminate it to gain memory space for a more general purpose counter... Anyway the link below is to that old radio-freq. display and it also contains a better pre-amp and some instructions how to get the most RF performance from it. www.qsl.net/dl4yhf/freq_counter/freq_counter
@@TheHWcave Thank you so much. I will go right there and have a look right now. I was just watching your other videos on this ) Nice modifications.
@@TheHWcave You are a star. Initially when I built it I wanted to keep the crystal tester too. So I built another preamp schematic externally that didn't work. Actually I built two of them. None worked. So last night I decided to built the preamp on the board as per your video.... and BAM ! Now it works and reads the frequency perfectly ))) Thanks so much buddy.
Hi! I have built your hack. I gave that one to a friend. It was so much fun that I am building a second one!
I would like to use the original header pins for the input to the pre-amp. Does the original frequency input pin stay active, after the pre-amp modification? If so, I would need to cut its trace and use a jumper wire to get back to R1/330R. Or, if the original pin is active, is it useful to keep?
I love your channel. Thank you for all your work to include and teach us!
Thanks for the kind words. The original input pin is still active after the mod but of course the signal isn't amplified. Actually it is worse, because of R3 and R4, of the mod, the signal on the original input is now DC coupled pulled high which means using the pin for input needs a signal that is sufficiently strong to pull the level low enough for the chip to register. Using the original input for a TTL kind of signal should still work.
As for using the original pin as input to the amplifier by cutting traces is a bit more tricky because the trace on which it lies is also used by the output of the amp to route the signal into the chip (this is the cause of the issue I mentioned above). Note that this trace also switches from component side to solder side right at that pin. So you need 2 cuts and 2 patch wires. Cut the pin completely free on both sides of the board. This needs 2 cuts, one on each side of the PCB. Then put a patch wire from the pin to R1 (330) as you mentioned. Then run another patch wire from the now floating end of R4 (270) to pin 3 of the PIC.
@@TheHWcave Thank you for your fast reply! Because the solution is more involved, I will just put the pin next to R1, as you had originally designed it. That is a rather easy solution, thanks to your clever thinking. I appreciate your help.
Perhaps YT deleted my webarchive link to the original pre-amp mod image. Anyway, the original uses 470pF for C1, but you use 470nF. Will this matter in performance? Is one preferred?
The higher the capacity of C1 the lower the frequencies the you can measure. The original design was to measure only radio frequencies, but I wanted to be able to measure the much lower audio frequencies as well. Note that the higher capacity still works for the high frequencies, so you don't loose out. Its a question of available space, a larger capacitor needs much more space. Also, if you never want to measure lower freq. then using a smaller capacitor acts like a filter to keep the unwanted lower freq. out. That can be an advantage for example to suppress mains power hum (50/60Hz or rectified 100/120Hz)
Do you think the input pre-amp can handle larger voltages? I want to add this display to a QRP radio, but my oscillator signal is 9V p-p.
If you use the simple pre-amp mod I suggested, the answer is yes. Make sure use the amps input capacitor to attach to your oscillator and don't go DC coupled to the amp or even directly to the PIC. I tested the counter with 20Vpp that way and it worked fine
Thank you for this vid. Gonna make this mod :). Rock it. You got my subscription.
Hello Heinz, I’m a beginner and would like to ask about the capacitor C1. What kind of capacitor it is?
I have no idea yet what kind of 470uF capacitor I will use for modifying. ...
Hi Masa,
the absolute value is not really important here. You can use whatever you have. The purpose of the cap is to remove any DC component from the signal which could damage the amp and let only the AC part of the signal through. The capacitor value determines the lowest frequency that can still get through and be measured. Higher capacitance values will let more of the lower frequencies go through. The other criteria is that it should be preferably un-polarized. Most electrolytic capacitors are polarized and should be avoided in this circuit. Best go for polypropylene film capacitors. They are easy to get and not expensive. Voltage wise, the cap should be rated for at least the highest AC+DC voltage you expect to apply to the input. Of course it is fine if the cap can handle more. Voltage rating mostly determines how physically large the cap is, so don't go overboard with the voltage rating or you end up with a monster that takes up a lot of space. The one I used is already an overkill, its just that I had it ready in my parts bin (scavenged from somewhere).
Thanks a lot for your kind comments.
Now I’m ready for assembling and also modifying this kit!!
Where do we connect signal. Is it at preamp on schematic R-1, and at what is labled IN at R-4. Is GND used for signal?
Thanks
Yes, R1 (330 Ohm) is the input to the pre-amp. R4 is the output of the pre-amp and goes to the INPUT of the PIC. Just one more thing. Be aware of the frequency response of the pre-amp. It works really well from about 200Hz to 20MHz but is not that sensitive for lower or higher frequencies. Especially if your plan is to do RPM measurements with this counter using a reflective optical sensor like the TCRT5000 (there are additional videos on that on my channel), I would NOT build the pre-amp (or at least not permanently connect R4 to the PIC because it would interfere with the sensor. RPM measurements are effectively frequencies in the
I need best firmware for PIC ...where can i find it please ?
I assume you mean "my" best firmware? Have a look at the last video of the series and the descriptions always have a link where to download the firmware
@@TheHWcave How can I make it read 32.768Khz crystals?
@@tinmachine722 My firmware should work with any frequency from a few Hz to nearly 100MHz (top limit depends on the quality of the PIC chip). It is a frequency meter.To test a crystal you need a circuit that oscillates with that crystal. I have never build the oscillator that is part of this kit. If that oscillator works with our crystal, I have no idea but if it works you would be able to measure it. I have strong doubts that ithe oscillator would work with such a low frequency. If you already have a circuit where this crystal is used, just use that instead and use the frequency counter to measure the output.
Hello, Heinz... I have built the model that comes with a yellow PCB. It seems to be very similar to the red model, with a few exceptions... One being that there is not a trimmer pot. And, I did not implement your amplifier.
My software seems to suffer from all of the limitations that you point out... The flashing last digit for higher frequencies, the digit offset, etc...
I have compared my pinout to Wolf's version1 and it appears to be 100* pin-to-pin compatible. So, I have a couple of questions, before I flash your hex...
- Do you know of any means to save the hex that came on the chip, in case yours doesn't work with my slightly different model? If so, I could use detailed instructions, as I am not a strong coder. I have a PICKit2 type clone that runs on the PICKit2 GUI.
- I would not think there was any connection between not having the amplifier and not using your software... Meaning, your software is not any more dependent on the signal strength than the original software; correctly?
- Can you think of any reason to not change the software to yours?
I had so much fun building the yellow model that I ordered two of the red model, just so I can do your exact upgrades. Thank you for the wonderful project and your many efforts to share it!
Thanks for the kind words. No, there is no dependency between the firmware and the amp mod. I only did the amp mod in one module and the one I used for later development (RPM measurement) simply left the complete crystal tester / amp mod part unpopulated. I did add the button in that one and in the one with the amp mod because the new software uses it to switch modes.
Hi there - I hope you are still online! For your Freq.Counter, were you able to get Heinz's firmware to work with the Yellow PCB version?
@@johncoops6897 This has been too long ago, for an old man to remember the details. However, I did find this note that I wrote, in the project box. "I flashed the HW Cave software/hex. Now, it seems to be gain sensitive. My Tenma [counter] works at 1/4 amplitude." Of course, this occurrence could be a coincidence, as opposed to a consequence. It seems more likely that; a hardware issue, not a software issue, as I did not add the amplifier. HTH.
@@t1d100 - thanks so much for replying! I am also an old man 😃
Luckily I just found a spare PIC processor, so I am going to flash that rather than risk the original chip. Cheers!
Super Video! Danke und Merci! 👍🏼
Hello. Have You tried LNA mmc rf amplifier 30db that is around 3Euro as preamp to freq meter?
No I have not. So far the re-purposed 1 transistor amp was good enough for my measurements. I just had a quick look at Ebay but the RF amps I saw were generally for much higher frequencies like 2GHz. Not much use for a counter that is limited to frequencies
@@TheHWcave
maybe too much, but 30db from DC upwards. ordered for $ 2 at Ali. I plan on adding an input capacitor. We'll see.
Part:
0.1-2000MHz RF Amplifier Wideband High Gain 30dB Low Noise Amplifier LNA Broadband Module Receiver
I am curious, please report back the results.
@@TheHWcave Well, I don't have signal generator and I can't do any testing. I wont to use this as a small portable frequency meter (battery powered).The price is a killer for making any board plus You get SMA connectors. I just wanted to give you a suggestion for more videos. Pre-amp is under 2$( lowest price I could find).
I can extend the cut-off frequency, such as 10uF capacitance should work to 5KHz(they say). Like 150mV should give about 4V on output ( all in theory and by Ali) on full range (up to 2GHz :-). All the best.
Another question, how do I get the counter to subtract 455KHz from the reading?
Hi Steve, I think the original firmware supported this. Mine doesn't unfortunately. I had to remove some code to gain space for all the new functions and the IF add/subtract was part of it. If you want to use this module to display frequency of a radio based on its IF, you need to use the original firmware and follow its instructions.
@@TheHWcave So that's why it didn't work. It still has the Add, Sub options in the menu but when I selected one it would quit counting. Isn't there a way to add more memory to the unit?
If the menu is still there you have not loaded my latest firmware but in your case that is fine because when using it radios as you apparently plan to do you need it, and only the very first version of my firmware retained the menu (because that was only bugfixes in the original, no new features). If I recall correctly, in general to subtract (or add) any frequency you need to feed it first to the counter. Then when its displayed, select subtract and press long to activate it. For subtract it will now show 0 and for add double (of course). To undo use the zero function.
In case of 455 kHz, it happens to be stored in a table of frequently used values. Select Table, press short until 455 is displayed.Long press to select it, press short until SUB is displayed, long press to select it. That should do it. Please I did not come up with this method nor can I provide any other advise on it. As I said, I needed space and chucked the whole menu thing overboard in subsequent revisions, including support for sleep mode ( power save), support for 4 Mhz vs 20 Mhz clock frequency, common anode displays and 4 digits vs 5 digits displays. Sorry but space is limited and there is no way to extend it on this hardware.
@@TheHWcave Are you sure about removing the add/sub function? I'm using your hex file from Github that puts the zero on the far right digit and it still has add/sub!
@@stevec5000 The zero in the right was the bug-fix version. The latest version shows a msg "Freq" or (RPMx or count) depending on the mode briefly at startup.
Hello my friend, I am not a lucky person! I bought 2 frequency counters from China like yours. The older one works fine and reads my VFO frequency perfectly. The second one I bought recently doesn't work with VFO even if you press the programming push button. I modified the circuit according to your fabulous easy explanation video but I cannot make it work at all. I tried changing the BJT9018 to 9014 because it has a HFE but unfortunately there's no way I can get it to work. Before changing the circuit the quartz tester worked. Do you have some idea what I'm doing wrong or why it is not working. I'm beginning to wonder that maybe the Pic programming has been modified by the productors. Hope you can help me solve this enigma!
If I understand you correctly you have 2 kits that both worked as quartz testers and then you modified one to convert the quartz tester into a pre-amp and now that kit does not work. Did I get this correct?
First of all my instructions were based on the assumption that the PCB was not already populated with the quartz test circuit, so that means you would have de-soldered all its components like the 9018 transistor, 1K, 10K, 2x 22p, 102. This process could have damaged tracks or pads. Then there are quite a number of tracks that need cutting and its possible that some were not completely cut through. That is worth checking with a magnifier and a multi-meter conductivity test. Beware that now the board is populated you may read some resistances values across cuts because of other components, but it should not be close to zero ohm. Then you need to install 3 wire jumpers and one jumper that can be probably made with a bit of solder but its in total 4 additional connections that need to be made. Its worth checking you did not miss one or that it goes to the wrong place. BTW, this assumes that the you removed the barrel power socket. If you kept it, there is one less jumper needed but then you must use the power jack to power the unit. It won't work if fed from the + pin header (pushing the jack in basically does the work of the jumper). The transistor needs to go in 180deg turned from what is printed on the board. Make sure it is oriented as shown in the modification video.
In general, does the display work at all (showing just zero) of is it completely dark ? If dark, check the power. Does the 7550 middle pin gets power?
@@TheHWcave Hi, thanks for your quick reply. Yes, you understand the problem. I wanted to transform one of the two kits into a frequency meter for a 40 / 20m receiver. I have removed all the components that were not needed and the display lights up regularly with the 0 illuminated, but it does not read the RF that generates the VFO. The power jack I have never soldered and I made the jumper as shown in the video. The other Diy kit that I use for quartz, after pressing the button on the right and making one of the programming flashes (it seems to me QUIT or other), works perfectly, but I always have to press the programming, so it is inconvenient. As soon as I can i will double check everything, but I think I have not done anything wrong (I also used a good magnifying glass). I'm not very lucky :-(
@@francomaresca4950 How do you connect your VFO to the board? Does the IN pin have connectivity to pin 3 of the chip? If you take the chip out, the IN pin should only show conductivity to the pin3 socket position and not to + or - . If you have the version with 4 pin-headers, remember that the most right one, marked G is not connected to anything. So your signal must be connected to the pins - and IN
@@TheHWcave Ok, over the weekend I double-check all the PCB, including the connection between IN and pin3 of the Pic. I'll let you know as soon as I'm done with all the tests. ;-)
@@TheHWcave Hi !, this morning I armed myself with testers, videos, screenshots and a magnifying glass. I have not found any errors in the execution of the change. Everything you have described in a simple way I have done to the letter. So I decided to buy another DiY from the same alix seller, the one that works without modification (unfortunately I can't swap the pic between them to check if one of the two is faulty) or give up and go directly to the construction of a frequecy meter with ICM7216DPI which reads up to 50mhz without prescaler. Thank you for your assistance and patience. Have a nice Sunday :-)
thanks for this video and the work youve done just modded my version i got today and built and it works fine tested with sine and square waves even the software update i kept an original pic software so i can go back to the offsets if required at a later date i had 2 kits and when i compared the 2 original pics location 20 in the data memo were diff one set to 00 the other 01 dont know why that was unless thats were the menu settings are set and i may have changed one before i copied them
Nice to hear of your success. By the way, I did a few further tweaks and videos of the firmware to allow more features, like higher resolution for low frequencies, RPM measurements and event counting.
@@TheHWcave done the latest firmware Ive just ordered 3 more as im building a test unit to monitor 3 guidance antenna input frequencies that are generated from 3 signal generator modules for test purposes and i need to know they are at correct freq your mods have made my task better thanks again
bist du deutsch?
New verison I get two days ago have signal pre-amplifier and display built as 5 digits in one component with 14 pins.
Interesting. Where did you get this new version from?
Better quality image from 5:00 is here: web.archive.org/web/20190302134149im_/homepage.eircom.net/~ei9gq/schem.png
Yes, many thanks for the tip
I ordered one just for grins. It has an input sensitivity of exactly 887,600uv. Isn't that awesome? hahaha!!!!
Before I realized this PIC stuff was a total scam and would never work I ordered a second counter, got that today and it doesn't work either! Microchip isn't far away over in Chandler so I have half a mind to go down there and complain about the crap they are making except the chips I got are probably fakes! With the new chip, when I turn it on it shows 8.8.8.8. and if I press the button it goes to something like C.E.F.E. except it's backwards! Maybe the LED displays are the wrong language like Russian or something?
When the display is showing 8888 (I mean more than a single digit), it means the multiplexing seems to work and responding to a button press also would mean that the PIC is at least not completely dead. If I understand correctly, you now have two kits built. I think you seem to say that the 2nd kit behaves different from the first one. So the first thing to try is to swap the two PICs. If the error remains with the board, it means it is probably the PCB and the other hardware and not the PIC.
Another thing to try is to remove the PIC completely and power-up the kit. Now the display must be completely dark. If any segments are on, this means checking for faults, solder bridges or components that are put in the wrong-way around Without the PIC in the socket, you can check the display wiring for correctness. Example: use a wire to connect pin 2 with pin 5 in the PIC socket, and then use another wire in pin 14 and with the other end touch pins 6..13 in succession. That way you can test all segments of the first digit. Repeat this for the rest (ground on pin 2 = 1st digit, pin 1, 18, 17 = digits 2..4). Digit 5 is special. All you need to do is make sure NOTHING is connected to pins 2, 1, 18, 17 and then use the other wire pin 14 to 6..13 to test its segments. If you can't test digit 5 in isolation (i.e. it comes on with other digits) or not at all, check the 9014 transistor and the 3 diodes.
This is very brief of course. Let me know how you are getting on.
@@TheHWcave I made some progress with the counters, finally finished the kit and it does work somewhat, it can read the freq. of a crystal plugged into the socket but still can't count the freq. of an input signal. Found several problems with the prebuilt one, first the chip won't work on the kit I built, is either bad or programmed incorrectly, also the LED displays are the wrong type so the whole thing is useless!
Glad you are making progress. The crystal tester circuit is pretty rubbish. If you don't need it, I would remove it. Alternatively convert it to a pre-amp for the freq. counter (see video). The input on the PIC is a Schmitt-trigger type but still kind of targeted at TTL signal levels. Certainly do not feed negative signals or signals greater than 5V