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remote Fan controller help

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aruna1

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I was making a remote fan controller.circuit and programming is finished but there is only one last problem remains.

sometimes circuit some how change speed(increase count on 7 segment and increases speed) without giving any IR signal.
its like IR receiver virtually received a IR signal.I'm driving a stand fan.I'm not sure this is because fan is a inductive load and i have no idea where is the problem(whether 12F675 pics up a interference signal or TSOP1738 pics up a interference signal and lows its output.)there are no other IR sources in surrounding.(only IR remote i use to operate this)

circuit responds to IR signal properly

I have attached my schematic here.

I use zero cross detector interrupt pic. IR signal is checked using polling.

can someone point me the error and show me a solution?

thanks.

this is the only problem I'm having to finalize my project:confused::eek::(
 

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aruna1

Member
well i just removed ir sensor and replaced it with push button.with push button i dont have this problem.it seems IR module is generating signals some how.so i replaced it with a new one but it didnt solved the problem.
 
well i just removed ir sensor and replaced it with push button.with push button i dont have this problem.it seems IR module is generating signals some how.so i replaced it with a new one but it didnt solved the problem.
Did you re-write the code when you substituted the switch for the IR receiver ?

If not then you must not be detecting valid remote codes, just detecting an IR pulse to change speeds, etc. If that is the case it is no wonder you get erratic operation. The striking of a match, inhaling on a lit cigarette, rubbing your hands together briskly, etc. can all generate enough IR energy to be detected by the typical IR receiver.

You could also remove led0 and r7 and use pin 6 as the input for the receiver module and use external mclr. Since you have a 7 segment display to show speed what purpose does this led serve ? Is it to indicate power or reception of IR ?
 
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aruna1

Member
Did you re-write the code when you substituted the switch for the IR receiver ?

If not then you must not be detecting valid remote codes, just detecting an IR pulse to change speeds, etc. If that is the case it is no wonder you get erratic operation. The striking of a match, inhaling on a lit cigarette, rubbing your hands together briskly, etc. can all generate enough IR energy to be detected by the typical IR receiver.
i dont send remote codes.only a pulse.therefore i didnt have to rewrite code.

You could also remove led0 and r7 and use pin 6 as the input for the receiver module and use external mclr. Since you have a 7 segment display to show speed what purpose does this led serve ? Is it to indicate power or reception of IR ?


led is to indicate timer mode.

and what is you mention about mclr? i didnt get it.
 

p55xp

Member
I do not understand how a switch can substitute an IR-receiver still receiving the ir-signal. Is the switch is now used for controlling speed? How the purpose will be accomplished then?

Even if the problem still persists, you can try the following :
1) re-compile your code, re-programme it in a new chip;
2) re-solder all joints - loose connection may cause false signaling;
3) triacs generates nois as it switches the ac/dc power line, try a better nois filter - just mimic it from a commercially available electronic fan regulator,
OR,
purchase a good quality electronic fan regulator then, --
a)disconnect its' triac's gate from its circuit
b)now reconnect the gate to MOC3022 of your circuit

Don't forgate to post your success news

It's better to use a coded signal then get decoded it within your microcontroller otherwise what is the justification of using a micro?
 
Last edited:

aruna1

Member
I do not understand how a switch can substitute an IR-receiver still receiving the ir-signal. Is the switch is now used for controlling speed? How the purpose will be accomplished then?

Even if the problem still persists, you can try the following :
1) re-compile your code, re-programme it in a new chip;
2) re-solder all joints - loose connection may cause false signaling;
3) triacs generates nois as it switches the ac/dc power line, try a better nois filter - just mimic it from a commercially available electronic fan regulator,
OR,
purchase a good quality electronic fan regulator then, --
a)disconnect its' triac's gate from its circuit
b)now reconnect the gate to MOC3022 of your circuit

Don't forgate to post your success news
tsop1738 low its out put voltage when reciving 38khz signal.so i just add a switch between pin 4 of 12F675 and ground.when pushing it lows pin 4.

my problem was solved just moment ago.i added 4.7uF cap between output of TSOP1738 and ground.and it seems working now
 
tsop1738 low its out put voltage when reciving 38khz signal.so i just add a switch between pin 4 of 12F675 and ground.when pushing it lows pin 4.

my problem was solved just moment ago.i added 4.7uF cap between output of TSOP1738 and ground.and it seems working now
You only think the problem is solved. Strike a match or light a cigarette lighter or puff on a cigarette in front of the IR receiver and your fan will change speeds or turn off. Possibly even switching on the light will make it act up, especially if it is a flourescent light fixture.

The point I was making about mclr is that it is best practice to use external mclr, especially on a device that interfaces to AC mains. External mclr is much more reliable reset of the microprocessor.
 
It is not connected to the problem you will have picking up stray IR signals. It just makes your application more robust and less likely to act up due to power fluctuations. You connect mclr pin to +5 volts thru a 33k ohm resistor with a capacitor to ground at the pin also. It isn't mandantory to use external mclr but using external mclr can be helpful if you have power fluctuations.
 

p55xp

Member
It is not connected to the problem you will have picking up stray IR signals. It just makes your application more robust and less likely to act up due to power fluctuations.
Mike is correct, but it may not solve your problem. In my opinion if your problem persists still now even after placing the capacitor - it comes from spurious signal generated by the triac.
Place a 0.1µF capacitor between Vcc and Gnd in the nearest vicinity of the microcontroller. It is almost a standard digital circuit design practice.
 

aruna1

Member
It is not connected to the problem you will have picking up stray IR signals. It just makes your application more robust and less likely to act up due to power fluctuations. You connect mclr pin to +5 volts thru a 33k ohm resistor with a capacitor to ground at the pin also. It isn't mandantory to use external mclr but using external mclr can be helpful if you have power fluctuations.
problem is i dont have any more free pins.so i have to use mclr as input

Mike is correct, but it may not solve your problem. In my opinion if your problem persists still now even after placing the capacitor - it comes from spurious signal generated by the triac.
Place a 0.1µF capacitor between Vcc and Gnd in the nearest vicinity of the microcontroller. It is almost a standard digital circuit design practice.
I'll try it

thanks everyone
 
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