Hello, this is my first post.
My son's Cambridge Audio A500 amp volume remote control stopped working with his new setup and he has no remote control that works with it.
As he's lazy and minted (LOL) he decided to buy a new fancy Sony AV amp and gave me the A500 amp to hack about with. The motorised pot was broken (I swapped in an ALPS I already had) and the BA6218 motor driver also needed replaced after an unfortunate mix up with connectors (fzzzt).
I noticed almost immediately on inspection of the schematics, that the PIC16C54 is the same pinout as a 16F628a that I have lots of and is cheap, and had already written IR code in PROTON basic for a more complex preamp I made over a decade ago that also had extra features including input selection...
I modded the code in a few minutes and it now reproduces the ON LED and Vol UP/DOWN IR of the original A500, but "pretends" to be a Sony TA-E77ESD preamp.
This means the CA A500 is compatible with far more (cheap) universal remotes.
With a bit of tweaking and IR code look ups, it could be made to respond as almost anything required.
As a bonus, CrownHill Proton Basic is now end of life and free:
https://www.crownhill.co.uk/category-41.html
Files attached are the Proton basic file and a hex for programming the Pic.
I wonder if anyone else in the universe might find this useful? (haha)
Cheers.
My son's Cambridge Audio A500 amp volume remote control stopped working with his new setup and he has no remote control that works with it.
As he's lazy and minted (LOL) he decided to buy a new fancy Sony AV amp and gave me the A500 amp to hack about with. The motorised pot was broken (I swapped in an ALPS I already had) and the BA6218 motor driver also needed replaced after an unfortunate mix up with connectors (fzzzt).
I noticed almost immediately on inspection of the schematics, that the PIC16C54 is the same pinout as a 16F628a that I have lots of and is cheap, and had already written IR code in PROTON basic for a more complex preamp I made over a decade ago that also had extra features including input selection...
I modded the code in a few minutes and it now reproduces the ON LED and Vol UP/DOWN IR of the original A500, but "pretends" to be a Sony TA-E77ESD preamp.
This means the CA A500 is compatible with far more (cheap) universal remotes.
With a bit of tweaking and IR code look ups, it could be made to respond as almost anything required.
As a bonus, CrownHill Proton Basic is now end of life and free:
https://www.crownhill.co.uk/category-41.html
Files attached are the Proton basic file and a hex for programming the Pic.
I wonder if anyone else in the universe might find this useful? (haha)
Cheers.
Hello PMcCloy!
Just created an account to thank you for the idea, I have been remote-less for a couple of years now, and for the sake of £2 for a PIC decided to give it a shot.
I think my version must be an earlier version of the board, since the PIC pinout is slightly different. A couple of updates to the code fixes that one easily. For some reason, my Proton Basic doesn't seem to like SonyIn, so I decided to use RC5In instead, it gave an error at the assembler stage. I haven't programmed in basic before so it may have been a simple error, but since I was using a universal remote anyway it didn't make a difference.
Also, for some reason I cannot work out, the MCLR pin is connected to the IR signal through a set of two inverters, meaning the processor resets when an IR input is received. It makes no sense to me, but I am sure the Cambridge Audio engineers had their reasons! I ended up disconnecting the IR end inverter, so MCLR is always held high.
I added a mute function while I was in there, just leaving the low-side motor high for a second to quickly turn the volume down, only trouble being you have to slowly turn it back up again normally...
Anyhow, it is now all working correctly, many thanks again; if this wasn't the internet I'd buy you a pint!
Will.
Just created an account to thank you for the idea, I have been remote-less for a couple of years now, and for the sake of £2 for a PIC decided to give it a shot.
I think my version must be an earlier version of the board, since the PIC pinout is slightly different. A couple of updates to the code fixes that one easily. For some reason, my Proton Basic doesn't seem to like SonyIn, so I decided to use RC5In instead, it gave an error at the assembler stage. I haven't programmed in basic before so it may have been a simple error, but since I was using a universal remote anyway it didn't make a difference.
Also, for some reason I cannot work out, the MCLR pin is connected to the IR signal through a set of two inverters, meaning the processor resets when an IR input is received. It makes no sense to me, but I am sure the Cambridge Audio engineers had their reasons! I ended up disconnecting the IR end inverter, so MCLR is always held high.
I added a mute function while I was in there, just leaving the low-side motor high for a second to quickly turn the volume down, only trouble being you have to slowly turn it back up again normally...
Anyhow, it is now all working correctly, many thanks again; if this wasn't the internet I'd buy you a pint!
Will.
Hello.
I'm sure there's probably a few revisions of this amp, but with tweaking should all work.
The main reason I did it was because picking up an official remote costs more than all the parts I replaced, lol.
Another hack possible would be to add your own phono preamp if one is not already installed.
Already have a decent phono pre tho...
Cheers.
I'm sure there's probably a few revisions of this amp, but with tweaking should all work.
The main reason I did it was because picking up an official remote costs more than all the parts I replaced, lol.
Another hack possible would be to add your own phono preamp if one is not already installed.
Already have a decent phono pre tho...
Cheers.
