JP1 Remotes

digitaltoast · Joined: 25 Nov 2012 Posts: 3 Location: United Kingdom

I've got 3 perfectly good OFA URC-7210, AKA "Big Easy" remotes which could do with some JP1 love.

But after hours of Googling and asking a supplier of JP1 cables a question, I'm confused. Here's a pic (sorry, crappy phone camera):

The supplier said that despite it saying JP1, they THOUGHT it was actually a JP1.2 connection - the total inc postage would be close to £40. And it's a long way to return if the wrong one! Obviously, I realise I need to solder on my own header pins, but I've decided to make my own cable, probably the Arduino-based project seeing as I've got an Arduino kicking around.

As I understand it, JP1 is for EEPROM based URCs and JP1.2 is for FLASH (ie: single MCU like mine) based URCs.

EDIT: Just found this http://www.hifi-remote.com/wiki/index.php?title=JP1_Interfaces which says:

3FG · Expert Joined: 19 May 2009 Posts: 3367

Here's a related thread about the URC-7240. There is also a thread at RC which confirms that the 7210 uses 5 digit EFCs, but UEI says it does not have learning.

Anyway, this is very likely to be a JP1 remote. Your picture of the PCB has an 8 pin location labeled U2. That is very likely where the the EEPROM would go. The 7240 thread says that remote didn't have an EEPROM installed. The lack of learning capability also suggest that EEPROM is not installed.

So, look at the other side of the PCB to find out if U2 is populated. If it isn't you'll need to get a 24C16 class (2KB) EEPROM. I think ones with the correct packaging are difficult to find these days. Of course you'll also need to add the JP1 header

digitaltoast · Joined: 25 Nov 2012 Posts: 3 Location: United Kingdom

Thanks 3FG. Lots to read in that other thread!
I don't actually need to make it learn anything new, just reprogram the correct EFCs to the right keys. I know all the codes from this table and I've done in the manual way (as described on that page) but it's incredibly tedious like that.
So is this idea of using JP1 to re-assign existing EFCs to correct a layout actually going to need that EEPROM? Because I can see my soldering "skills" and something that small ending up in smoke and swearing!

3FG · Expert Joined: 19 May 2009 Posts: 3367

Yes, you need the EEPROM. The JP1 interface doesn't talk to the processor. Instead it uses the I2C serial protocol to read and change the contents of the EEPROM. JP1 can't access the small part of processor memory which is used for the EFC programming that you're doing now.

It is difficult to solder in the EEPROM. Make sure that you get a SOIC (or SOIC8) package, with a width including the leads of 5.8mm. The 16Kbit memory size is safest, but some people have installed 32Kbit EEPROMS and gotten them to work.

digitaltoast · Joined: 25 Nov 2012 Posts: 3 Location: United Kingdom

The Robman · Posted: Sun Nov 25, 2012 5:16 pm Post subject:

The EEPROM chip looks like, only thing I noticed is that it runs on voltage 2.5v-5.5v. Your remote only has 2 batteries, meaning it's 3v when the batteries are carrying a full charge. I would recommend getting a chip that runs on 1.8v voltage, just to make sure that it will work when the batteries are getting a bit flat. But if you've already ordered this chip, it'll probably work fine.

Also, I can't quite tell from the pic if the resistors in R11, R12 and R35 are all there, also the capacitor in C11. If any of those spots are empty, you may need to populate them.
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