Sky HD Remote - JP1.2 Photo

ragawu · Post by **ragawu** » Tue Nov 13, 2007 7:39 am

Hi,

I wish to investigate possibility of modifying this remote for JP1.2 use.

SkyHD Remote - Revision 3
URC1680-XXB00

Here is a photo of the PCB. Obviously the header in the middle is for the JP1.2 connection, however is the missing component U2 in the top right where the eeprom would go?

Any advice gladly received.

Alasdair

ragawu · Post by **ragawu** » Tue Nov 13, 2007 2:20 pm

I'm pretty confused, from what I've read in the forum posts, Jp1.2 remotes don't have an eeprom and use some sort of flash memory. What I'm unsure is if the flash memory is inside the small chip which is covered in a blob of resin on my pcb.

Or is there normally a separate flash memory chip?

In the spirit of blind adventure, I soldered on my header and connected up my JP1.2 cable. The remote still functions while the cable is connected, however no program has successfully registered it. JP1XTEST.BAT reports no remote found - The light on the remote blinks once rather than twice, and IR also finds no JP1.x interface.

I've triple checked my solder joints.

I'm unsure if my remote should have some flash memory attached, what 1 blink means (if anything) and whether my remote could just be 'locked' out of JP fun - wouldn't surprise me from Sky TV.

Just to say also that I can't find answers to this in the FAQ, stickies or 'Testing JP1.x Ver 3.pdf'. I'm pretty certain no one has worked on this remote before so maybe I'm at a dead end, however I'd love to get this working.

I've tested the interface and it returned the strings to N&B Com test no problem.

thanks again,

Alasdair

Post by **vickyg2003** » Tue Nov 13, 2007 2:34 pm

You need to post a picture of the back side of the board, to see what kind of chips it has. The button side of the board doesn't tell a lot.

binky123 · Post by **binky123** » Tue Nov 13, 2007 2:49 pm

You probably need a JP1 cable as JP1.x remotes don't have an area for an EEPROM chip to be soldered on. The EEPROM is built into the chip.

ragawu · Post by **ragawu** » Tue Nov 13, 2007 2:51 pm

The chip is underneath a small circle of resin about the size of a squashed garden pea. You can see this at the top of the pcb.

There is no big socketed chip like on my earlier revision sky remote.

Here is the underside:

ragawu · Post by **ragawu** » Tue Nov 13, 2007 2:55 pm

binky123 wrote:You probably need a JP1 cable as JP1.x remotes don't have an area for an EEPROM chip to be soldered on. The EEPROM is built into the chip.

I'm not certain position U2 is for an Eeprom, I was just conjecturing.

I still believe this remote is a JP1.2, but I'd be keen on finding out how big the chips are in similar remotes - (JP1.x universal remotes with no learning capabilities.)

ragawu · Post by **ragawu** » Tue Nov 13, 2007 3:15 pm

ragawu wrote:The chip is underneath a small circle of resin about the size of a squashed garden pea. You can see this at the top of the pcb.

There is no big socketed chip like on my earlier revision sky remote.

Maybe I answered my own question and this remote can not be modified.

johnsfine · Post by **johnsfine** » Tue Nov 13, 2007 3:21 pm

Can you trace the connections to the "JP1.2" holes and see what they connect to?

That would give us a pretty good idea whether/which JP1 interface it is.

Do you have a continuity or Ohm meter to check the connections? Maybe the soldering is bad.

The usual method of identifying a chip such as U1 (the one covered with epoxy) is to select a starting point to number the traces coming out around the edge of the epoxy and trace a bunch of them to specific functions, especially the IR LED control. Then that sequence can be compared to a few Samsung and Freescale datasheets to identify the specific part.

ragawu wrote: Maybe I answered my own question and this remote can not be modified.

I'm sure the chip under the epoxy has enough connections to be one of the Samsung or Freescale parts at the heart of a JP1 or JP1.x remote.
Probably it CAN be modified through that JP1.2 connection.

I can't quite see the LED end in either of your pictures. Am I correct in understanding there is both a red LED pointing up and an IR LED pointing forward?

Tracing the connections of the IR LED would help a lot toward identifying the design. For example, what we would normally expect to see is:

One side of the IR LED connects to ground. Hopefully there are enough other traceable connections to ground to identify ground.

The other side of the IR LED should connect to one of the three connections of Q1.

The other two connections of Q1 are probably resistors. The other side of one of those resistors should be a trace that runs under the epoxy and is the most important anchor position for use in converting a few relative trace positions into absolute chip pin numbers.

The other side of the other resistor is the power supply (probably direct to the plus side of the battery and to one of the pins of the JP1.2 connector.)

Actually, now that I described what to expect, I can almost see it myself in the picture you posted.

One side of Q1 connects to R6, the other side of which connects to the IRQ pin of the processor (which is pin 8, if this is the same JP1.2 chip that is in the 8820).

The other side of Q1 connects to R6, the other side of which connects to the very fat trace used for power. That runs down to the plus side of the battery connection.

Please try to trace a certain connection from R15. One side of R15 connects to the + side of the battery (bottom of your picture). Then, I think it runs under S43, S40, S34, an S54, then a branch comes off it to the right, going to the JP1.2 connector. If it is really JP1.2, that will be pin one of the JP1.2 connector. Make sure that matches the way you oriented your JP1.2 cable.

ragawu · Post by **ragawu** » Tue Nov 13, 2007 4:22 pm

Thanks John I'm giving this all a go right now, will report back.

ragawu · Post by **ragawu** » Tue Nov 13, 2007 5:12 pm

Correct on the IR and led setup.

The -ve side of the IR emitter goes to ground and the +ve to Q1.
If Q1 is a equilateral triangle sitting on an flat, IR +ve goes to the top, left connection goes to R6, then U1. And the right signal does go to R5 then Vcc.

From R15, trace goes exactly as you said

When I connect cable correctly and run JP1XTEST.BAT, I get "no remote found". The led pulses on for 1 second.

Looks like crap soldering then?

That's definitely my weak spot on this front.

I attempted to check the solder but it was hard to make sure my probe was touching the tiny pad rather than the pin itself, thus not proving that I don't have any dry joints.

I found it really hard to get a wet joint without flooding over the white gap between pads.

Apart from all this, sounds like there's still hope for my JP1 adventures. The sky remote is basically a 2 device unit but I have specific plans to use it to control just an xbox and my hifi, as long as I can get it pushing out the right signals I'll be happy. [The 8820 seems to have these facillities].

thanks for the great help on this.

ragawu · Post by **ragawu** » Wed Nov 14, 2007 6:12 pm

Somebody just promised me their weller soldering station, so hopefully by this weekend I can rule out the possibility of dry joints. I've been using a real joke of an iron up till now.

While I'm waiting, does anyone know if there's a possibility that this remote has been 'locked' out of JP1(.x) use? Has there ever been an example of this? What I mean is the hardware is there, but has been crippled for whatever reason (spoil-sports..?).

johnsfine · Post by **johnsfine** » Thu Nov 15, 2007 8:11 am

ragawu wrote:I attempted to check the solder but it was hard to make sure my probe was touching the tiny pad rather than the pin itself, thus not proving that I don't have any dry joints.

For ohm meter checking of the existing connections, I assume it is easy to get contact with the pin. Your problem was the other end. You tried to get contact with the pad.

It would be more helpful, where possible, to get contact with some more distant point on the same trace.

For example, we already discussed the fact that one side of R15 connects to pin 1. So skip the pad and check from that side of r15 to pin 1.

Pin 3 should be ground. You can pick up ground many easy places, so you don't need to try at that pad.

I think pin 2 connects to one side of R1 (R1 is near the epoxy blob).

Pins 4 and 6 each connect to sides of several of the key switches. I'm not certain the matrix is laid out the usual way on your model, but if it is, pin 4 connects to one side of switches 30 through 37 and pin 6 connects to one side of switches 20 through 27. The black F shape on each switch pad is conductive, so you can measure from that to the JP1.2 pin.

BTW, I hope you had batteries in the remote when trying to use the JP1.2 interface. It doesn't work without them. (But obviously you're better without batteries when doing those continuity checks on the pins).

ragawu · Post by **ragawu** » Thu Nov 15, 2007 10:13 am

Why didn't I think of that?

Pins 1,2 & 3 all test perfect - zero resistance.

Pin 4 & 6 show continuity but resistances of <200 ohms - I presume that's how they work out which switch has been pressed?

Pin 5 connects to one side of R2 and continuity is perfect here.

I also tested there was no shorts at the pin header - there isn't.

Batteries were in during JP1.2, even tried with them out to see any difference.

Batteries out during continuity tests.

Going to have a good look at my serial port, I can't think of any other variables in this problem (..well, except human error..).

Alasdair

ragawu · Post by **ragawu** » Thu Nov 15, 2007 1:17 pm

I don't believe my serial port is the problem.

If I monitor the serial port while running JP1xTEST.EXE I see the program send the E character (0x45) three times, each time the remote replys with 0 (or doesn't reply - I'm not sure how to tell the difference).

The remote's led pulses for 1 second and that's it. It also pulses for 1 second when I toggle DTR.

What would the JP1xTest program expect from that 0x45 signal?

Alasdair

johnsfine · Post by **johnsfine** » Thu Nov 15, 2007 1:28 pm

Sorry if I missed some background here, but why do we believe your JP1.2 cable is good? Did you test it with some other JP1.2 remote. Your results sound to me like the problem is the JP1.2 cable.