URC7140, JP1.4? How to connect

CambridgeMart · Post by **CambridgeMart** » Sat May 28, 2016 6:10 pm

I have a OFA URC7140 R02 and have built Tommy Tyler's IC Version of Serial JP1.2/3 (Flash) Interface; when I use IR, I get an error message JP12 read failed 0. I've followed the IDENTIFYING THE MICROCOMPUTER AND SIGNATURE OF AN UNKNOWN FLASH REMOTE procedure and find that the remote doesn't enter serial comms mode, although it does respond to the reset command; after some digging, I've found that this is probably a JP1.4 device - so how do I interface with it?

mdavej · Post by **mdavej** » Sat May 28, 2016 6:55 pm

Your remote is already supported. Try fresh batteries and confirm your pin-out is correct.

3FG · Post by **3FG** » Sat May 28, 2016 6:57 pm

We have a RDF file for the 7140 R02, so if the interface is ok, RMIR should work. IR.exe will not work.

CambridgeMart · Post by **CambridgeMart** » Sun May 29, 2016 5:26 pm

I've checked out the interface, it's properly connected and appears to be doing what I'd expect, it toggles the Reset line, the LED on the remote flashes twice and the interface outputs a few pulses on the RX line. RMIR just reports no remotes found.
Can I use the IC Version of Serial JP1.2/3 (Flash) Interface for JP 1.4?

3FG · Post by **3FG** » Sun May 29, 2016 7:48 pm

1. Post a link to the "IC Version of Serial JP1.2/3 (Flash) Interface". Otherwise we have to guess which Tommy Tyler interface design you mean.
2. It is possible that your remote has a different signature from the two we have for URC-7140 remotes. To check, download JP2Sniffer and read from the remote with it. Start with the High Level tab. If that doesn't provide a list of segments or has a signature different than 351101, go to the Low Level tab and click Begin Comm, GetInfo, and GetSigBlk. Post the results here.

CambridgeMart · Post by **CambridgeMart** » Mon May 30, 2016 7:03 am

The version I've built is the second one in the PDF here:
https://www.hifi-remote.com/forums/dload ... le_id=5958
I'm going to try the JP2Sniffer thing now

CambridgeMart · Post by **CambridgeMart** » Mon May 30, 2016 3:32 pm

Well JP2 sniffer didn't help much, still no comms. However, what I did discover is that DTR on both COM ports of my machine (1 in built and another using a Prolific USB to RS232 unit) have DTR set to logical 1 which is -6V or -10V, depending on the port used; the JP1.x adapted uses DTR to pull up the collector of the gate driving the RS232 port RX pin; with DTR set -v.e., RX will never go high, so the program reports no comms.

3FG · Post by **3FG** » Mon May 30, 2016 5:15 pm

Perhaps you can pull up the RX line using the Vdd line instead of DTR.

The use of DTR as a pull up is really problematic because JP12Serial does manipulate the line to handle really old interface designs, and secondly some ports send DTR and others send (NOT DTR). BTW, I know this is all good fun, but for less than $10, you can get a FTDI based USB cable that will work very well.

Post by **The Robman** » Tue May 31, 2016 6:41 am

Details on the FTDI cable here...
https://www.hifi-remote.com/forums/viewtopic.php?t=16360

CambridgeMart · Post by **CambridgeMart** » Wed Jun 01, 2016 3:45 pm

OK, so I bought a FT232 adapter which didn't have a RTS line; some careful soldering and I added a new connection to the chip and I now have a working interface

JP2Sniffer is reporting 351101, so it looks like I'm all set to start hacking