Remotely Controlled Motorized Volume Pot.

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Ok, had a rumage in the boxes of bits, now have a new set of transistors.

The mute function now works if pin 10 is shorted to 0v :)

Thanks for the offer of a code change but I dont have any spare buttons on the remote, only have Volume + & - and the mute. All other are used by the CD player :(

Cheers
 
Ok, had a rumage in the boxes of bits, now have a new set of transistors.

The mute function now works if pin 10 is shorted to 0v :)
OK, that's fine :).
Thanks for the offer of a code change but I dont have any spare buttons on the remote, only have Volume + & - and the mute. All other are used by the CD player :(

Cheers
Now drop me a link to post you - within half an hour - a modified program code to solve your problem. Actually i will remove the "Inhibit MUTE" command if "STBY mode" exists.
Fotis
 
Yes all is working fine, BC546, fitted inverse :)

Could pin 3 be triggered "On" with just a time delay of a few seconds rather than a pysical button push on the remote?
If "pin 3" you mean the output for MUTE relay, it is automatically triggered - for a while - during power-up to prohibit audible thumbs from power supply.
OK, the modified HEX file is ready for you, i've programmed P16F88 with MPLAB ICD-2 to be sure that is working, and is working just fine on my test board.
Unfortunatelly i can't upload it on diyAudio forum because does'nt accepts HEX files. Also in Matrix Multimedia forum because my moderator duties, and this is a custom HEX file for you.
Fotis
 
Custom Remote Control Handset

For whichever is interested to build his own Remote Control Handset, here the link of a whole article:Matrix Multimedia user forums • View topic - Remote Control Handset "1"
It is implemented around a PIC16F1827, one of the recently launched micros of Microchip. This micro together with PIC16F1829 includes the new Data Signal Modulator (DSM) module, that is very useful for remote control handsets offering up to 32MHz carrier frequency. Its cost is some big at 7.5 Euro (you can buy from e-bay ready RC5 remote control handsets of Philips for just 6.5 Euro cluttered from tenths of useless buttons!) but is a DIY project :).
Fotis
 
A year ago I would have been real interested in this remote volume control, and I appreciate the generosity of the code writer. In the last year I found that I can bluetooth 16 bit stereo digital wirelessly from my smartphone to my main stereo system in my living room. The Bluetooth receiver I bought for $20 from Parts Express in Ohio works pretty good, and only needs a 5 volt power supply or handy USB port to tap off of. I think that may be the future of front end sources, and my phone has volume, EQ and the mute function. The digital files don't have to be mp3. I have a bunch of mp3 which was given to me, as well as my own stuff that is all wav files without compression. Not super highend really, but pretty darn good. All my CD's are 16 bit... It's difficult to find the bluetooth recievers on the Parts Express website, but they are there. They don't tell you, but if you drive 32 ohm headphones directly with the bluetooth receivers (they say it can), they have a bunch of hash noise for some reason. Drive into 500 ohms or above and I didn't hear any noise at all. Feed it into an aux in on your preamp. Like most cheap Chinese stuff, the included instructions are very minimal.
 
Hi Fotis

I had a few issues once a added the IR reciever on an extention cable, have now just folded the legs on the reciever and will drop it throught the chassis, will work fine but wondered wg=hat type of cable would work?

Also the unit does not seem to hold the remote data, each time I power it up I have to go throught the configration process:confused:

Other issue is that the motor is not powerful enough to turn the extention shaft and knob full rotation:smash:
 
Opps....forgot to add photo:rolleyes:
 

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Hi Fotis

I had a few issues once a added the IR reciever on an extention cable, have now just folded the legs on the reciever and will drop it throught the chassis, will work fine but wondered wg=hat type of cable would work?

Also the unit does not seem to hold the remote data, each time I power it up I have to go throught the configration process:confused:

Other issue is that the motor is not powerful enough to turn the extention shaft and knob full rotation:smash:
Hi Dag
I'm sorry to hear that you still have issues.
1) I allways try to mount the PCB as is on the front panel. In this direction i did the PCB drawing, the IR receiver is placed in 3 to 3.5 cm distance from mot pot shaft on PCB so there is enough space to not be covered from the knob of potentiometer. If there is need to place in a distance the PCB from IR receiver i use stereo screened cable, though most people use simple 3 conductors flat cable without problem.
2) Regarding remote control address, if your handset transmits a true RC5 code there is no case for the micro to not store into its EEPROM and hold the address code. Neverthless, because i did a small mod in your custom code i will take again a look on it to confirm you that is working properly.
3) From your picture, it is clearly that the motor of potentiometer has to turn a relatively heavy load. I can see a long extension shaft, a coupler and 3 supporting holes of the shaft on your cassis. To be sincere, i've never tried a such type arrangement, but if the whole extension armament of shaft is not in perfect alinement then will be "bend" due to the weight of the heavy solid aluminum knob. In such a case, you could turn the knob manually without trouble. But the motor of potentiometer is a unit of small torque and probably will have problem. Additionally - from electrical view - the actual voltage that applied on the motor is just 3.5V, the rest 1.5V from the total 5V of supply is the voltage drop accross the transistors of "H-bridge". It should be noted that these 4 transistor (Q1, Q2, Q3, Q4) are biased into full saturation when the micro activates either of the 2 driver transistors (Q5, Q6) and the base resistors (R1, R2, R3, R4 which are carefully selected to not cause extra voltage drop). The nominal voltage of motor is 4.5V but if this can resolve your problem, you could remove the 5V supply of PCB to Q1 and Q2 and to connect their collectors in an extra supply source of 6V, thus you will have: 6V-1.5V drop = 4.5V exactly as much is the nominal supply voltage of motor. Please take a look on schematic to understand what i described.
I quote bellow - again - the process of remote controll RC5 address initialization:
The microcontroller is programmed to communicate with any RC5 compatible remote control handset. Each handset transmits a unique RC5 address code, e.g. TV address = 0 and Preamplifier 1 address = 16. To initialize the microcontroller for communication with a remote control handset turn off its power supply, wait for a while and turn it on again - causing thus a master reset. The red LED mounted on PCB immediately starts to blink fast for 10 times. Within this time, press firmly the button mounted on PCB until LED stops to blink and remains constantly glowing. Release the button. Now, within 3 seconds, press firmly a button (MUTE is preferred) on remote control handset. If its address code has been stored successfully into micro, the LED blinks slowly 6 times. If we don’t press any button on remote control handset then the TV address code = 0 is automatically stored into micro and the LED does not lit. If the remote control is incompatible with RC5 protocol the LED starts to blink fast for 10 times and then again the TV address = 0 is automatically stored into microcontroller. That is all. The internal EEPROM of microcontroller retains constantly the address code.
 
Hi Fotis

Q1 & Q2 or Q1 & Q3?

Q1 and Q3. In schematic is clearly shown that the collectors of these transistors are connected in +5V supply rail. Leave Q2 and Q4 (which of emmiters are connected to GND) as is!
Just now i looked in program and i found a small mistake in the beggining of code that causes the need of re-initializing micro each time power is applied! Sorry friend for the confusion, i removed the related command and now everything works OK.
Check please your mail box, you have a new message with the corrected HEX file attached.
Don't forget to make initialization of micro again, then re-apply power to check if everything went OK.
Fotis
 
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No need to worry, tested the pot with 5v directly to the terminals and it still got stuck! As you say, a very small misalignment will cause it to fail.

I will have to re-think this now as the whole idea was to keep all of the audio circuitry well away from the high voltage EM84 VU displays.

Option 1, move pot to the front of case and try to sheild it for the VU meters

Option 2, use this setup on a solid state project ive been working on :(
 
Hi,
I used an over the counter remote controller.

It works resonably well, but I have a problem that I would like to improve on.

When adjusting the volume control, the digital control/adjusting signals cause a quiet buzzing clicking in the speaker output. Pretty quiet when the vol is stationary.

Is this likely to be motor noise or control circuit noise?
Where do I look to try to find a way of reducing that noise?
 
Hi,
I used an over the counter remote controller.

It works resonably well, but I have a problem that I would like to improve on.

When adjusting the volume control, the digital control/adjusting signals cause a quiet buzzing clicking in the speaker output. Pretty quiet when the vol is stationary.

Is this likely to be motor noise or control circuit noise?
Where do I look to try to find a way of reducing that noise?
Hi Andrew
Digital control - included of course the motor of potentiometer - power supply must be separate from this of analog section. That is the best practice, i allways use it and never had interference issues. There is issue if digital and analog section share a common GND node or rail. Motor is noisy during rotation, microcontroller internal oscillator (4MHz) could also add a small noise - be it so inaudible. With a scope you could see this noise on analog signal path. Thus i never had to solve such a problem like that you refer and so i can't enlighten you :eek:
Cheers
Cheers
 
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