frequency meter pic led display

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megamicro

Joined: 23 Jan 2003
Posts: 14

24 Jan 2003 16:05 lc meter 16f84

This is a good LC-meter not only for hobby electronics.

The link is:
http://www.aade.com/lcmeter.htm

I didn't have pic16c622 and I changed the code to use pic16f877.
The pins must stay the same.

Here is my version

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cipo

Joined: 26 Jun 2002
Posts: 29

05 Mar 2003 19:03 lc meter avr

Hi!

Here is another link with full description: http://www.hw.cz/constrc/lc_metr/

Cipo

cheolim

Joined: 03 Dec 2002
Posts: 160

06 Mar 2003 11:54 avr lc meter

Hello, all.

Is there any reference for C-measurement with MCU, range from 300pF to 360pF with accuracy +/-0.3pF.
I'd like to achieve the resolution of 0.2pF. Is it possible?
If possible, I prefer to use R because better accuracy than L.

Someone who is expert to L,C,R measure, pls help me.

Thanks in advance and regards.
Rolling Eyes

tgq

Joined: 15 Jul 2002
Posts: 305
Helped: 2

13 Mar 2003 14:40 pic lc meter

hi megamicro
this is a good job !
'The pins must stay the same' what does it mean ? to use A0..A3 and B1..B3 pins for LCD, B4 for Rly and so on ?
Could u pm the modified asm code, i'd like to use a 16F628
Ans finally did u make a nice PCB ?
Thx

pool_77

Joined: 08 Aug 2001
Posts: 220

13 Mar 2003 17:44 lc meter

Dear Tgq,

Please inform the forum, when you modify the code!

pool_77

tgq

Joined: 15 Jul 2002
Posts: 305
Helped: 2

03 Apr 2003 10:13 simple lc meter

Ok pool_77
I found the original asm file
1 error removed Very Happy

I must check each register adress because the author ignores the standard Mchip include files Confused

The code can fit into a nice and cheap 16F84 which is the rough EEprom equivalent to the Eprom 16C61 Wink

tgq

Joined: 15 Jul 2002
Posts: 305
Helped: 2

03 Apr 2003 10:26 lc meter pic16f84

The code I found seems to be an old version Sad

16F877 hex code is 50% longer than the 16C61 asm code I get after assembly
So please megamicro give us the original 16C622 asm code, so we can adapt it to use a 16F628
16F877 is too big and expensive for this job Wink

Thx

megamicro

Joined: 23 Jan 2003
Posts: 14

04 Apr 2003 16:34 lc meter atmel

tgq wrote:

The code I found seems to be an old version Sad

Thx

OK, I check all I have:

1. lcmeter_pic16c61.asm - the original asm file, but I'm not sure that
it's OK - it was from the time when this lc-meter was free and there
was a lot of bugs.

2. lcm_622.asm - the last well working version using PIC16C622.

3. lcm_877.asm - my changes of the first 16 operators for initialisation
of the registers.

2&3 are good working versions - they are big enough and cannot fit
in PIC16F84. Only the size of the program is important - there isn't
any spetial register use, adc or comparator or ...
... that means you can use any PIC with enough memory!

Regards, megamicro

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megamicro

Joined: 23 Jan 2003
Posts: 14

04 Apr 2003 16:43 lc meter 2051

tgq wrote:

hi megamicro
'The pins must stay the same' what does it mean ?
Thx

that means you have to use PB0...PB7 from PIC16C622 as PB0...PB7
for PIC16F877 and so and so... only change the pin numbers according
to MICROCHIP datasheets for each new micro.

It's clear for me !

mgajo

Joined: 15 May 2001
Posts: 347

04 Apr 2003 21:38 lc meter based on pic16f84a

Hi
What about measuring results
Anyone tested ?
Confused

pool_77

Joined: 08 Aug 2001
Posts: 220

05 Apr 2003 16:01 lc_meter.hex

I tested some capacitors,
accurancy is better than 3% in interval up to 1uF.
The worst accurancy have C with worse D (quality).
for example: C with D=10-6 has 0,5%
and with D=10-5 has 2,5%
higher capacitors are measured with less accurancy.
I am trying some changes of tank circuit now.

pool_77

Borber

Joined: 01 Jan 1970
Posts: 1561
Helped: 117
Location: Slovenia

06 Apr 2003 4:59 lc meter pic

I have made LC meter according to cipo post. Both construction uses the same principle of measurement (LM311 oscillator with tank circuit). The only difference is tank inductance 68uH and 130uH. The capacitor has the same value practically.
I fount that error is rising with C value measured. It is about +10% at 2.2uF. It is due to the way it is measured (oscillator frequency depends on tank element losses).

atmel2000

Joined: 23 Mar 2003
Posts: 12

06 Apr 2003 6:22 lc meter pcb

Hi,

there is some mistake in the upper results. Take a look at:

http://www.aade.com/lcm2binst/HP.html
and
http://www.aade.com/lcm2binst/Accuracy.htm

and you'll see what you have to have as results for this good lc-meter.

no more than 1%. The most important for this is the capacitor 1020pf.

Thay use exactly this value in the calculation and if you don't have
this or this capacitor is not stable - the error is going up.

I've made a lot meters like this one and realy the error usualy
is less than 1%!!!

delailed description is also available:

http://www.aade.com/lcm2binst/LC2Binst.htm

pool_77

Joined: 08 Aug 2001
Posts: 220

06 Apr 2003 16:19 lc meter use 89c51

Dear Atmel 2000,

My experience is following:
If I change the 1020 capacitor (e.g to 1025 or 1010), I only see moving of interval of all measured values down or high but the variance (dispersion) of measured values is much higher then inaccuracy derivable from changing of 1020 cap.
I can addust e.g 0,5% error for cap. up to e.g. 1nF, and and 3% up to 1uF with percentage erros variance about 4. (I have coil with Rs=0,2ohm).
If I change Rs of coil to 1ohm, I get variance of errors about only 1,8.
I am testing plastic capacitors (MKT,MKS,polystyrene)

Which capacitors did you tested?

tgq

Joined: 15 Jul 2002
Posts: 305
Helped: 2

07 Apr 2003 9:16 hex code for very accurate lc meter

In fact, as the LCM accuracy depends on the 1020 pF precision, I'm working on a combined LC-Meter with self-calibration : a separate C-meter section would measure thru another relay the 1020pF value, and then store the real capacitance in PIC memory Smile

We can find 0.1% resistors, so i'm looking for a good PIC C-meter, it would ideally get the resistor precision ... We could make a LMC555-based oscillator, but I don't really know if it gives an effective excellent resolution Laughing

Fragrance

Joined: 26 Jul 2002
Posts: 1385
Helped: 24

07 Apr 2003 14:44 lc meter 89c2051

Hi, Megamicro

I compile your uploaded files but with lot of error why you did not uploaded the real one file

what the reason

regards
fragrance

atmel2000

Joined: 23 Mar 2003
Posts: 12

07 Apr 2003 23:56 lc meter pc

Hi, Fragrance

did you realy try to assemble this asm files?

There was no problem for me, that means for anyone too!!!

I'd like to help you with uploading a compete project including
the file lcm_877.asm from megamicro.

There wasn't even one error !!!

Use MPLAB and you can sleep better.

regards, atmel2000

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tgq

Joined: 15 Jul 2002
Posts: 305
Helped: 2

08 Apr 2003 13:45 lc meter schematics

Hi Fragrance
I use MPASM 2.30 :
- LCM_877 get out of assembly whith no error
- LCM_662 with no error
- just a little one in LCM.asm for 16C61 : comment in label RAMLOOP starting with ' instead of ;
The only thing is that LCM_662 and LCM_877 are disassembled so it is really hard to re-use these files in another project Sad

And I dont know if the LCM.asm for 16C61 is bug-free ???

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08 Apr 2003 13:45 Ads

Fragrance

Joined: 26 Jul 2002
Posts: 1385
Helped: 24

08 Apr 2003 15:07 atmel lc meter

Hi,

Last time i compile the program with mpasm 2.30 with error, ok i will test the latest upload file , by the way in my poor knowladge that if you deassemble a hex file some user define math rutine and multiplecation rutine will not desassemble is i am right?
if so how this program work fine

regards
Fragrance

atmel2000

Joined: 23 Mar 2003
Posts: 12

08 Apr 2003 21:44 lc meter pic16c622

Hi, Fragrance

yes, you are right. But as megamicro said yet this project is not free now.
First original asm file is from the time when it was free but with errors.
We have the latest hex-file for one good working lc-meter. He didn't
have C61 and the hex file was disassembled only to check what
exactly must be changed in order to use F877 and that's it.
We have a lot of code&lib about lcd, math, ...
If you need something else, please you can disassemble this hex and
find what you want.

The topic was GOOD LC-METER, not lessons how to disasm hex at all.
If you need it - build one, otherwise use what we have yet and make
something different.

Atmel2000

tgq

Joined: 15 Jul 2002
Posts: 305
Helped: 2

09 Apr 2003 8:36 lc meter pic16f628

Yes atmel2000, if we want to make another project like me, it will be much more simpler to use a good compiler with built-in math float and LCD routines, instead of loosing time trying to understand a disasm hex file

hadihf

Joined: 29 Mar 2002
Posts: 136
Location: Planet Earth

02 Sep 2003 7:55 lc metr

Hi tgq,
Do you have the PIC16F628 files for the LC meter? I have 628 and not 622 Crying or Very sad

Lucas

Joined: 28 Apr 2003
Posts: 11
Location: french

02 Sep 2003 10:08 l-meter at89c2051

I find an other at:
http://xavier.fenard.free.fr/LCMeter.htm

it used a ATMEL chip and its completely free, with the source.

I am going to try
lucas :)

Fragrance

Joined: 26 Jul 2002
Posts: 1385
Helped: 24

08 Sep 2003 16:13 89c2051 lc meter

hi,

nice link i also give a try to it and told the result after testing it

good work

hadihf

Joined: 29 Mar 2002
Posts: 136
Location: Planet Earth

03 Oct 2003 11:36 lc metre

Hi,
If you can understand turkish... Confused

try this...but it is usefull anyway

http://www.antrak.org.tr/gazete/111998/barbar.htm

Regards

hadihf

Joined: 29 Mar 2002
Posts: 136
Location: Planet Earth

18 Oct 2003 9:04 lc-meter-pic16f628

Hi,
I have build the 'good LC meter' and have some problem and experience to share,
First the experience Cool

-the coil for F1 showd be of very low resistance<<100milliohm and wide range core ferrite material 20KHz ~ 1MHz.
-use a trimmer of 10~20p parallel with Caliberation Cap.
Problems Sad

- how to minimize stray inductance?
- the stray source..switches, tracks etc. etc can somebody guide on track layout...component sellection etc.
I am attaching an excell sheet for F1 & F2 behavior while changing C caliberation.

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SphinX

Joined: 25 Jan 2002
Posts: 1069
Helped: 28
Location: EGYPT

19 Oct 2003 23:20 make lc meter-electronic-schematic.php.htm

Hi,

This LC is the same as the one described here
But with nice PCB + asm&hex for pic16f84

Pharaoh Of Egypt

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hadihf

Joined: 29 Mar 2002
Posts: 136
Location: Planet Earth

20 Oct 2003 6:40 lc meter pic 628

Hi.
FIY, in this latet post for LCM with PIC16F84, the Ccap is actually 1000p and not 1020p as wrongly shown on schematic(check in asm!). I gues this is the earliest version of a/a/d/e/ LC meter with PIC16C61...when it was free...modified for PIC16F84...the switches are 2PST...with 4PST contact is improved.

look at www.freddospage.nl

Regards

Fragrance

Joined: 26 Jul 2002
Posts: 1385
Helped: 24

20 Oct 2003 7:30 l-c meter lcd nokia3310

hadihf wrote:

hi friend hadihf and Pharaoh of Egypt

I realy thankfull for pharaoh of egypt that he provide the lc meter in the result hadihf provide the orginal link to the page which have lot of other use full information because that the right way, any way thanks for the both, i think that the right thing which we are wiating for pic 16F84 based lc meter

radiohitplus

Joined: 17 Nov 2003
Posts: 1

17 Nov 2003 19:43 lc meter nokia 3310

Dear friends, I have to built the LCmeter with the plans found in http://www.antrak.org.tr/gazete/111998/barbar.htm

but when i turn on the circuit, it LCD show four black boxes. what's happen somebody can help me?