JP1 Remotes

[vda]

Hi All,

I have a One For All URC-7740 that does not have a JP1 connector at all, but on the plastic case there is a place for it, so I thought it might be a JP1 compatible remote control. After opened up the casing, I found a single chip with the following written on it:

N434
3C80F9XLN-SOB7
(c) UEIC 2003
J4A95

Do you think it is a JP1 candidate and if so how can I make a connector to it - I mean to which pins of the chip?

Thanks.

vda

[The Robman]

Have you seen this...
http://www.hifi-remote.com/forums/viewtopic.php?t=8674

There appears to be another version with the parts, according to this thread:
http://www.hifi-remote.com/forums/viewtopic.php?t=3962
_________________
Rob
www.hifi-remote.com
Please don't PM me with remote questions, post them in the forums so all the experts can help!

[vda]

Thanks Rob, I have seen them all, but they didn't help. Mine is a version without JP1 connector, so I wonder finding the version with JP1 connector to see if I can make a missing parts, although in one of your post you said you have soldered the missing parts but it didn't work. However you were not sure that was the same RC, so I am still hopping that making a JP1 connector for it is possible.

I have uploaded the images taken from my RC here:
http://www.hifi-remote.com/forums/dload.php?action=file&file_id=7840

If any of you have some images of the JP1 version of this remote control, or the datasheet of the 3C80F9XLN-SOB7 chip, it would definiately be very helpful for me.

Thanks,

vda

[The Robman]

Those pics definitely help, the remote that I modded years ago had empty spots for components, whereas you're doesn't. Looking at your PCB, you would also need to add an EEPROM, so you would need to create an additional circuit board for the EEPROM and possible some resistors and capacitors, along with the 6-pin, so you're looking a quite a major undertaking, with no guarantee that the firmware in the main chip can even handle an EEPROM.

Here's your data sheet though (look for the 32 pin chips on page 1-8):
http://www.hifi-remote.com/files/chip-manuals/S3C8-data-sheet.pdf
_________________
Rob
www.hifi-remote.com
Please don't PM me with remote questions, post them in the forums so all the experts can help!

[vda]

Well, I could be wrong, but I think the big chip actually has some flash memory inside (otherwise how could it remember the settings?). I would like to believe that the S3C8 datasheet is the datasheet of that "big chip" - 3C80F9XLN-SOB7 written on it - but even if that is true, according to the datasheet, there is only one I/O pin used for both reading and writing to the flash memory whereas the JP1 connector has two pins (Rx, Tx) for that purpose... So how could they be wired together?

[The Robman]

Does your remote remember the settings even if you leave the batteries out of it for a while? To test this, program the remote then take the batteries out and press a button, or short the battery terminals, which will discharge the capacitor in the remote, then re-load the batteries and see if the settings are still there.

If they are, then maybe it is an S3F8 flash chip after all, but if they're not, it means that the S3C8 ROM chip was storing the settings in it's RAM.
_________________
Rob
www.hifi-remote.com
Please don't PM me with remote questions, post them in the forums so all the experts can help!

[vda]

The remote did remember the settings without battery for 3 days, but when I shorted the capacitor's terminals, it got reset.

So Rob, you are right. This one has no flash inside and it is not worth dealing with it.

Thanks for your help on this one.

vda