diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Analog Line Level (http://www.diyaudio.com/forums/analog-line-level/)
-   -   Remotely Controlled Motorized Volume Pot. (http://www.diyaudio.com/forums/analog-line-level/207419-remotely-controlled-motorized-volume-pot.html)

fotios 23rd February 2012 07:11 PM

Remotely Controlled Motorized Volume Pot. + Free Software
 
1 Attachment(s)
Of course, there are a lot of similar projects on the market that offered either like pre assembled units or like kits. Here the difference is that the HEX code to program your own PIC16F88 is FREE!
The unit is remotely controlled with the use of RC-5 protocol. A brief description of unit: It offers the VOL+ and VOL- functions plus STBY and MUTE.
The micro is programmed to communicate with any RC5 compatible remote control handset. Each handset transmits a unique address code, e.g. TV address = 0 and Preamplifier address = 16. To initialize the micro for communication with a remote handset, we have to turn off the supply of micro and then to turn it on again. Then immediately the red LED starts to blink fast 10 times. Within this time we have to press firmly the button mounted on PCB until LED stops to blink and remains constantly glowing and then we release the button. Now, and within 3 seconds we have to press firmly a button (MUTE is preferred) on remote control. If address has been stored successfully, then the LED blinks slowly 6 times and we can release the button. If we don’t press any button on remote control then the TV address code = 0 is automatically stored in micro and the LED does not lit. If the remote control is incompatible with RC-5, then the LED starts to blink fast for 10 times and in micro is again stored the TV address = 0. That is all. The internal EEPROM of micro retains constantly the address code that stored.
In the picture you can see that I have connected the IR receiver with a screened cable of 20cm to the PCB. This not cause interference or missed signal problems and, at the same time, offers flexibility in the mounting of IR receiver IC on front panel of device.
For more details, schematics, PCB drawings and... of course to download the free HEX file (with it you can use any programmer able to program a PIC16F88) please here:

Matrix Multimedia user forums • View topic - Remotely Controlled Motorized Volume Pot.

coolnose 26th February 2012 11:35 AM

Hi fotios,

nice project.

Could you tell me how you managed the behaviour of the pot for single push/constant push oh the remote control ?

Thanks,

Max

fotios 26th February 2012 05:56 PM

Quote:

Originally Posted by coolnose (Post 2923285)
Hi fotios,

nice project.

Could you tell me how you managed the behaviour of the pot for single push/constant push oh the remote control ?

Thanks,

Max

Thank you Max
I hope you know some things about RC-5 transmition protocol. The process is based on the examination "If Toggle Bit flips state". When a button on remote control is firmly pressed the "Toggle Bit" does not change state, while if button released it does. In program code and for VOL+ and VOL- functions, the test "If Toggle Bit flips state" is omitted and a time delay of 100ms in the specific program loops prevents empty intervals between succesive train of pulses. So, as long as VOL+ or VOL- buttons on remote control are firmly pressed, the potentiometer is rotated continuously. When button is released the rotation stoped.
On the contrary, for STBY and MUTE functions "If Toggle Bit changes state" is taken into account in program code. So if e.g. the STBY button is firmly pressed, the receiver does not change continuously state. We have to release and to press again the button to do so.
Hope i was somehow understandable.

fotios 26th February 2012 07:11 PM

1 Attachment(s)
Quote:

Originally Posted by coolnose (Post 2923285)
Hi fotios,

nice project.

Could you tell me how you managed the behaviour of the pot for single push/constant push oh the remote control ?

Thanks,

Max

Max, here is a FlowChart that might help you understand better?

coolnose 26th February 2012 09:11 PM

Thanks Fotios,

your answer is spot on and much more precise than my question actually.

Max

fotios 4th March 2012 12:58 AM

PCBs and microcontroller
 
4 Attachment(s)
Though i offered the program code free as a gift to diyAudio members instead a money donation to forum (is the same thing) some people asked me for availability of PCBs and pre-programmed micros. Most of them are users of "Lightspeed attenuator". For this use, there is no need for an expensive ALPS Blue Velvet motorized pot (23 Euro the lowest price on e-bay) or for the RK16 series (16 Euro). Recently, the well known for its quality BOURNS launched a range of economic motorized potentiometers for audio use. Mouser has stocked some values (10K, 50K) of these potentiometers for 9,50 Euro/piece. I allready ordered two pieces to try them. So, i will draw a second PCB with the footprint of BOURNS.
I think BOURNS will make the job pretty good.
Well, I can offer you pcbs and micros in the less possible expense. To this, pcbs will be simply tinned - no solder mask, no silkscreen - for saving cost, like this on the first picture.

1) A simple PCB with the programmed micro mounted on it:
18 Euro + 4,5 Euro p&p (registered parcel) + 1 Euro PayPal fees = 23.5 Euro (see picture 2)

2) Ready assembled PCB (see picture 3):
30 Euro + 6 Euro p&p (registered parcel) + 1.6 Euro PayPal fees = 37.5 Euro

It should be noted that the PCB can be divided in two parts with the use of a blade. The one part is for the potentiometer while the other for the control circuit.
For any question or help, please don't hesitate to contact directly with me in the e-mail address shown bellow in my signature.

P.S. Please Mr. moderator, don't move the post in Swap-Meet forum.

fotios 4th March 2012 09:55 AM

REMOTE CONTROL HANDSET
 
A remote control handset with just 4 functions (i.e. 4 buttons for VOL+, VOL-, STBY, MUTE) as many as supports the microcontroller in the current project will be available very soon. The program code is ready and tested with success on actual hardware. Simply i am on the search to find a suitable ABS handheld case in the lowest possible price. I don't want the price of the final device to be more than 7 to 8 Euro.
In this way i will save myself and other people from those universal remote controls cluttered from 30 to 50 useless buttons. Another one benefit of this custom handset will be its transmition address = 16 or 19 which are the RC-5 protocol predefined addresses for preamplifiers. So, no messing with TV sets, CD-Players and vice-versa.
To the present i have located 3 - 4 good plastic cases in small dimensions. This in the first photo is a TEKO that costs arround 4 Euro. It is nice, but to obtain a better price i should place an order of 200 pieces :eek: at least.

deChrLam 4th April 2012 11:31 AM

Wow, great work man. Very nice of you to free the knowledge and source.

I have a old JDM Programmer and a spare PIC16F84 lying around from a old infrared project.
Can I use the PIC16F84 instead of the PIC16F88 with your plans?

Time to go to the basement and get my etchant, toner-transfer paper and copper boards.

Cheers,
deChrLAm

Leon08 5th April 2012 07:24 PM

I think PIC16F84 can be used as any other PIC also, but you need to change the code.

fotios 5th April 2012 08:42 PM

Quote:

Originally Posted by deChrLam (Post 2972326)
Wow, great work man. Very nice of you to free the knowledge and source.

I have a old JDM Programmer and a spare PIC16F84 lying around from a old infrared project.
Can I use the PIC16F84 instead of the PIC16F88 with your plans?

Time to go to the basement and get my etchant, toner-transfer paper and copper boards.

Cheers,
deChrLAm

Thanks for your kind words
Unfortunatelly P16F84 does not includes internal oscillator block. P16F88 includes INTOSC block and i use it. It is callibrated at 8MHz. I suggest you to buy a P16F88, is not so difficult to find it and is cheap. Otherwise - in the case you insist in the use of P16F84 - except code changes you should make and changes on PCB layout because you have to add an external XTAL of 8MHz and the associated caps (2 X 15-33pF).
For me, is not so difficult to change in program code the mcu and its configuration settings, but i haven't a P16F84 :( to test the changed code on actual hardware.
Please let me know.


All times are GMT. The time now is 07:31 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2