JP1 Remotes

Hello!

Firstly say that I am very grateful to all those who have contributed to this site, as I have finally managed to solve a tricky problem with your help. I also have a technical question for you.

I'll ask the technical question first, as most of you will not be interested in the finer details of my path to enlightenment! To cut a long story short, I built a simple interface (parallel) without connecting JP1 pin 5 (RESET) to the DB25 pin 4, but the interface still worked. Why is this, and is there anything I won't be able to do as a result of this omission?

Thanks again,
Al

PS If you want to know why I didn't connect JP1 pin 5 (RESET) you'll have to read on ... I've mainly included the detail below in case it helps others in similar situations in the future.



How I finally got discrete on/off and tray commands into my Philips Prestigo SRU8008 remote

So, I own a Philips Prestigo SRU8008 Universal Remote (non-JP1) and have been using it successfully for a year or so - it's a good product. The only problem is getting new codes into it as it isn't upgradeable; thankfully it is a learning remote so this provides an avenue for getting new codes in.

When I first set up the Prestigo I needed to get a few discretes in, and I had Pronto hex codes, but no Pronto, so I concocted a somewhat complex workflow:
(1) use Python script "pronto2lirc" to convert pronto hex to lirc conf files
(2) upload lirc conf files to my Squeezebox Server
(3) use the IR-Blaster plugin on Squeezebox Server to output commands:
(4) onto Cambridge M1+ Multimedia Explorer learning remote, and then:
(5) onto Philips Prestigo learning remote.

You might be wondering why I had to go via the M1+. The signal from the squeezebox IR-Blaster was quite weak through the IR-eye (which came with a scart video sender I had lying around) and the Prestigo often didn't pick up the command correctly. The M1+ has a much better learning facility and would pick up the commands from IR-Blaster fine.

Anyhew, this workflow was working fine until Christmas. I upgraded our home cinema setup and set about configuring the Prestigo again. Everything was fine until I got to the Sony BDP-S360 Blu-Ray player. I had previously done discretes for a Sony DVP-NS36B DVD player and a Sony STR-DE445 receiver so assumed everything would be fine. Unfortunately the M1+ showed LEARN ERROR every time I tried to blast one of the Sony Blu-Ray discretes. At first I thought that the signal might not be strong enough, so I built an amplified IR blaster using guidelines at http://tinyurl.com/irblaster but it made no difference apart from being able to get the learn error from slightly further away. I then had the idea of trying to learn (non-discrete) buttons from the original Sony RMT-B104P remote, but they generated the same error as well, indicating that the M1+ was probably at fault. I tried learning direct from the amplified IR-Blaster straight to the Prestigo but it was sporadically unsuccessful at best.

I then remembered that I had a OneForAll URC-7544 lying around that I had received with a Nebula DigiTV card and had previously used to make the Sony DVP-NS36B region free, and wondered if I might be able to find a device code for the Blu-Ray player. Obviously there was nothing in the manual but googling for a solution led me to this site. I had actually thought about using JP1 before, but on the list of JP1 remotes at http://www.diygadget.com/jp1/jp1enabledremotes.html I had misunderstood that it said "no" for "learning" - I had thought that this meant it could not be reprogrammed using JP1, whereas obviously it means that it won't learn commands from other remotes. I felt stupid, but at least I now realised that this might be a solution to my problem.

I then realised that my desktop PC had died in August and that as such I no longer had a parallel or serial port anywhere - or did I? I managed to dig out an ancient Compaq PR1000 docking station for my HP NC4000 notebook, and lo there was a parallel port onboard. I downloaded Tommy Tyler's excellent guide to building a Simple Interface (Rev5) and set about finding the part numbers for Maplin (UK). In case anyone needs this info, you need: 1 x JB59P, 2 x M1K, 1 x QL80B, 1 x YQ48C, 1 x JW87U, and 1 x XS28.

I sat down today to build the interface and started at the IDC connector end. The guide at http://www.i-hacked.com/content/view/28/90 is very helpful as the colour-coding on the 6-core cable I was using was the same as in the photos. I had to trim the JP1 connector surround on the remote to fit the 10-way IDC connector in (I used the middle six connections). Once I had checked continuity on all six cables I set about constructing the DB25 end. At this point I checked I my components and realised that the guy at Maplin had given me two diodes and only one resistor! The shops were already shut so I resigned myself to the fact that I would not be able to finish the project tonight, but set about doing what I could. I did all the soldering apart from the yellow wire connecting JP1 pin 5 to DB25 pin 4, as that was where I required the missing resistor.

I had recalled reading somewhere (it turned out to be http://www.hifi-remote.com/jp1/simple/index.shtml) that only the diode needed to be in place to pass the "check interface" test in IR.EXE, so I thought that I could at least test that. At first there was no response, but setting the parallel port mode to NORMAL instead of EPP in the laptop BIOS led to me being able to connect to the remote. I speculatively attempted a download from the remote and was somewhat surprised to see my remote identified correctly. I assumed that perhaps I had enough connection to read from the remote but not to write back and was pleased with the progress made. Even more speculatively I changed the device code of the TV function and attempted to upload to the remote, and was even more surprised when the setting appeared to be retained. Rather than risk it suddenly not working I quickly found the KM files for the Sony Blu-Ray and used the spreadsheet to do the upgrade for the VCR device on my remote.

After unplugging the remote and replacing the batteries (it wouldn't connect with the batteries in) I was finally able to discretely turn the Blu-Ray off and on and operate the disc tray. The commands have now been learned by the Prestigo remote and I am properly up and running!

I hope some of this information helps those in similar situations, and I would also be interested to know why the cable still worked even without JP1 pin 5 connected.

I must say I enjoyed reading about your journey into JP1 land. It made me smile.

bat400 wrote:I hope some of this information helps those in similar situations, and I would also be interested to know why the cable still worked even without JP1 pin 5 connected.

The Reset line in the JP1 EEPROM interface holds the remote's CPU reset while the EEPROM chip is being accessed. This is done to prevent a collision where both would try to access it at the same time. It also holds the CPU port pins in a tri-state condition so there won't be contention (two devices trying to drive the same node).

I suspect that it worked for you because the remote did not try to access the EEPROM, which is fairly normal as it usually only does so in response to pressing buttons. There was no contention as the CPU port pins are normally tri-stated when the I2C buss is idle.

However, the remote may not re-read the EEPROM contents fully until it sees a reset, so it is possible that not all the information you uploaded has taken effect. In your case, you had the batteries out, so a reset occurred when you reinstalled the batteries.

Bottom line, I would not recommend this as sooner or later it will cause problems.

mr_d_p_gumby wrote:The Reset line in the JP1 EEPROM interface holds the remote's CPU reset while the EEPROM chip is being accessed. This is done to prevent a collision where both would try to access it at the same time. It also holds the CPU port pins in a tri-state condition so there won't be contention (two devices trying to drive the same node).

I suspect that it worked for you because the remote did not try to access the EEPROM, which is fairly normal as it usually only does so in response to pressing buttons. There was no contention as the CPU port pins are normally tri-stated when the I2C buss is idle.

However, the remote may not re-read the EEPROM contents fully until it sees a reset, so it is possible that not all the information you uploaded has taken effect. In your case, you had the batteries out, so a reset occurred when you reinstalled the batteries.

Bottom line, I would not recommend this as sooner or later it will cause problems.

I have done it now, and it still works (I know I shouldn't be surprised). One noticeable difference is I now get the double-flash on the remote once an action is complete. It also now works with the batteries in and I can operate the remote while still connected to the computer with IR.EXE.

Cheers,
Al