42 replies to this topic

[Mr.RC-Cam]

Both of your drawings are incorrect. All you do is disconnect pin-2 on the PIC from the other circuitry. Then connect pin 2-to pin-8. EVERYTHING else is the same.

If you are using a 2.4GHz Futaba R/C system then you will never experience false R/C signal loss. Any signal loss that is detected will be real and significant (and useful if you allow the LOMA to report it). So, I don't recommend that you perform the silence modification.

[juancgc]

then is this?

or I could draw like please, you do not quite understand the lyrics?

and with respect to the futaba 2.4, what happens is that if I turn off the transmitter, the alarm is not active, the receiver stores the last signal received, then it is as if he were still arriving signal and activates the hill I never , turning the transmitter.

thanks

Both of your drawings are incorrect. All you do is disconnect pin-2 on the PIC from the other circuitry. Then connect pin 2-to pin-8. EVERYTHING else is the same.

If you are using a 2.4GHz Futaba R/C system then you will never experience false R/C signal loss. Any signal loss that is detected will be real and significant (and useful if you allow the LOMA to report it). So, I don't recommend that you perform the silence modification.

Attached Thumbnails

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[Mr.RC-Cam]

As explained, you disconnect PIC's pin-2 from the circuit and then connect pin-2 to pin-8. As shown below.



The point of the mod is to put pin-2 at logic ground. This tells the software to disable the glitch count function.

[juancgc]

ok ... thank you very much

As explained, you disconnect PIC's pin-2 from the circuit and then connect pin-2 to pin-8. As shown below.



The point of the mod is to put pin-2 at logic ground. This tells the software to disable the glitch count function.

[jlaercio]

Loma rode with a buzzer that pulled out of a dial-up modem and it just vibrated and the sound did not come with 4 pieces and tried none of them worked so I put a buzzer that pulled out of a larger UPS and will be worked perfeito.Porque Buzzer they did not work? Their model is PAC-1205.
Please help me and thank you.

[Mr.RC-Cam]

I think you will find that the buzzers that do not work with LoMA are simply the wrong type. Many 1205 type buzzers are missing the required internal drive oscillator (the buzzer you use must have an internal 4VDC-5VDC oscillator drive circuit). To test this, connect your buzzer directly to a 4.5V power source and verify you hear the loud buzzer tone. Also, measure the current to see that it is under 40mA. If these conditions are OK then it should work with LoMA.

[dbarry722]

Hi Folks..

I'm having a bit of a problem with buzzers as well. I bought the following but for some reason, they don't seem to work until I discovered that the buzzers seem to be external drives:

http://www.maplin.co...ransducer-98112

I've tried sourcing others but can't quite put my hands on any. Off to have another hoke(look) but if anyone can shed light this side of pond I'd be grateful.

Regards

Declan

[Mr.RC-Cam]

I've noticed that if the part's catalog description only mentions "piezo transducer" then it usually requires an external drive. The ones with internal drives (which LoMA requires) usually mentions "buzzer" or "built-in oscillator" in their description. No doubt there are exceptions, so simply review the data sheet -- it will tell all the details.

No experience with it, but maybe this one will work:
http://www.maplin.co...indicator-98109

Edited by Mr.RC-Cam, 16 June 2011 - 06:28 PM.
Added maplin part number

[dbarry722]

I've noticed that if the part's catalog description only mentions "piezo transducer" then it usually requires an external drive. The ones with internal drives (which LoMA requires) usually mentions "buzzer" or "built-in oscillator" in their description. No doubt there are exceptions, so simply review the data sheet -- it will tell all the details.

No experience with it, but maybe this one will work:
http://www.maplin.co...indicator-98109

Cheers. Many thanks

Just ordered some up. Don't know how I missed that one!!

Declan

[IceWind]

Hi,

Is is possible to convert the code to a Pic12F675?
I have several available here so it would be great to use them for this.

Thanks.

[Mr.RC-Cam]

Sorry, but I don't have a code version that would correctly compile for use on a '675.

[IceWind]

Well I tried to flash it but of course it didn't work.

Your version seemed easier to use and with some added cool features compared to others I've seen.
I just feel too lazy to go and do one.
Thanks anyway.

[chrispaiva]

Rc-CAM,

I was looking for a LMA project and then I run into your LMA.

I have some 1uF tantalum caps laying around, would it be possible use them instead of .1uF ?

Thanks,

Christian

[Mr.RC-Cam]

The recommended microcontroller decoupling caps are ceramic 0.01uF to 0.1uF.

[chrispaiva]

Thanks for your prompt reply.

Another question.

I have this buzzer with the following specs;


Oscillation Frequency (Hz) 3000 ± 500
Operating Voltage (Vdc) 1.5 ~ 30
Rated Voltage (Vdc) 12
Current Consumption (mA/max) 12 at Rated Voltage
Sound Pressure Level (dB/min) 80 at 30cm at Rated Voltage

My question is, I will use this LMA in a Plank and my battery pack is aroung 6V.

In my understand, I need to get 12V to have the louder db (as rated voltage) Is there a way to double my battery pack voltage (6v) to have a louder noise ?

[Mr.RC-Cam]

Operating Voltage (Vdc) 1.5 ~ 30

This tells me it is a piezo sounder and not a buzzer. The item you have requires an oscillator driver circuit whereas the one spec'd for the project will make noise simply by applying 5VDC to it.

Also, the PIC will be damaged by 6V so you need to add a 5V Voltage Regulator to the LoMA. Or perhaps drop the power supply voltage with a couple of series diodes in the Vcc supply.

But to answer your question, if you want to operate the buzzer on a voltage higher than 5V then you will need to add a transistor stage to drive it. I'll leave that part up to you.

[chrispaiva]

You are right checked the PIC voltage range 3.0 to 5.5 V.

I can remove one cell from the pack.

Check the link of the a buzzer a have

http://www.mallory-s.../PK-21N30WQ.pdf

I have read the some diodes can do that, Do you agree ?

[Mr.RC-Cam]

Check the link of the a buzzer a have

I don't have any experience with it so I can't say if it is a good choice. If it has an internal oscillator, works on 5V, and requires less than 40mA, then it should be fine.

FWIW, I have found that high frequency alert tones are not good choices for a lost model alarm. The higher frequency tones are often too directional and attenuate too quickly for this application. So try to select one that has the lowest possible audio tone frequency and highest sound pressure spec. The buzzer recommended in the project (http://products.cui....pdf?fileID=8247) works fine using ~2.3KHz and is quite loud). I don't recommend anything with a frequency that is much higher than that.

I have read the some diodes can do that, Do you agree ?

Diodes can be used to drop the power supply voltage. Be sure that the PIC never sees more than about 5.25V with a fully charged pack.

[chrispaiva]

Suddenly I found one buzzer in a old fax modem card (pci) I had.




Only thing I am in doubt, I applied power over the buzzer terminals and I could not hear a sound. Does it need the PIC in order to produce the frequencies or it should do a noise without the PIC ?

Edited by chrispaiva, 07 May 2012 - 06:30 AM.

[Mr.RC-Cam]

You must use a Buzzer with built in oscillator; The PIC does NOT provide the audio frequency. The correct buzzer choice for this project will be the type that makes the noise as soon as you apply 5VDC.