USB to Serial Cable with older JP1.x interface?

[csete]

Took another look at my circuit... Honestly, I'm not sure how I managed to get it looking so bad... I can't even follow it, let alone debug it... I think it is time to give up, throw it out and start over from scratch... try to get something that isn't such a mess from a layout perspective...

[WagonMaster]

I think it is time to give up, throw it out and start over from scratch... try to get something that isn't such a mess from a layout perspective...

I've built all 3 of Tommy Tyler's JP1.x RS-232 ("serial") hardware interface designs. Two are currently on breadboards and one is wire-wrapped/soldered as I described earlier. Assuming you don't have any JP1.1 remote controls to deal with and are only going to be working with JP1.2 and/or JP1.3 remotes, I'd recommend Tommy's quad-XNOR 14-pin DIP (74HC266) design since it has the smallest part count and is easiest to build, especially if you're going to be soldering "from the get-go" and not bread-boarding or wire-wrapping first.

The only problem is that the 74HC266 IC (Mouser part number 595-SN74HC266N -- ignore the non-"PDIP-14" "Package/Case" variants) is not as readily available (e.g. at Radio Shack) as your typical NPN transistor (e.g. 2N3904). Also, that web page shows that the 74HC266 chip you'd need is out of stock ("On Order") currently, but if you order anything else along with any out-of-stock part, Mouser ships that part for free when it's back in stock.

Oh, and if you do decide to build the 3-transistor design, be sure to download the latest version of Tommy's design. It was updated very recently to change the value of one resistor and to correct a duplicate resistor numbering. This allows the remote control to be used (e.g. for testing your programming of it) while still connected to the JP1.x interface.

Bill

[csete]

Given that I'm trying to get this silly thing built sooner rather than later, I'm more likely to build based on what is available at Radio Shack (ie 3 transistors)... I've been building per the latest design, including the 100k resistor, etc.

I feel stupid really... I knew that the board was turning out messy as I was doing the work yesterday, but I pressed on. I should have just stopped, since debugging such a rats nest of wires is just near to impossible.

[3FG]

Well, this thread has finally put me over the edge. Look, I understand wanting to do it yourself, and that's clearly part of the reason that we horse around with JP1 remotes.

But....
You really should consider just spending the $35 (shipped) to get Tommy Tyler's USB 1.2/1.3 interface. It works with just about any operating system, works with any computer that has a USB port, and it is well crafted. It's also small, self-contained, and can be stored in a drawer, briefcase, etc. without fear that some of the soldering will come loose.

The various RS-232 or parallel port designs are already problematic to use with newer operating systems or computers. That situation is just going to get worse.

And when we build an interface,we're not really "doing it ourselves", unless we write all of the relevant software, and design the circuit. So there's no shame in just buying the interface, just as there is no shame in using the wonderful programs, upgrades, extenders, tutorials, etc. that are available here.

Too expensive? I'll bet the time you spend building and debugging the hardware, and getting it to work with the various computers and OS would work out to be much less than minimum wage, compared to $35.

But you already knew all of that, right? So the real reason for this post is to assure you that Tommy's USB interface works right out of the box. The various interface designs from the early days of JP1 were based on using a minimum number of inexpensive components, and used the processing power and memory of the host computer to do the work. And that tended to make them a litte bit cranky to use. The USB interface has its own micro that does the communication with the remote. The data is transferred over the USB port using drivers supplied by the chip manufacturer. So the interface to and from the computer is standard USB, and supported by just about any personal computer.

Of course, if you still want to do it yourself, well, actually, I completely understand!

[csete]

Wow! What a post

While I am a bit of a cheapskate, it really isn't about that. I do like to "do it myself" every once in a while. I don't mean to clutter up the boards with my stories of failure... hopefully I don't sound like I'm whining too much and I'm definitely not pointing fingers at anyone else. The problem is that now that I've started down this path I'm not good at giving up... I feel like I'm being beaten (by my own stupidity usually) and I have to finish. As my wife would say, I'm "on a mission" to get things going and since I broken my working circuit now I feel obligated to myself to fix it.

I do have my limits where this kind of stuff is concerned, but I haven't quite hit them yet. I will stop bugging this group now and get the freakin' thing going... Tommy has been more than thorough in his schematics and troubleshooting. It all comes down to me getting it right.

[WagonMaster]

I feel a need to respond to "3FG"'s post.

While I don't doubt that any/all of the hardware that Tommy Tyler sells is worth every penny, there's an ethos about "doing it yourself" (DIY) that often has immeasurable value.

Also, I think that the JP1 circuits are a perfect example of something that's sorely lacking today -- a good excuse to build a truly useful electronic device.

The various RS-232 or parallel port designs are already problematic to use with newer operating systems or computers. That situation is just going to get worse.

I cannot speak for the parallel port issues at all. I don't have any JP1 (EEPROM) remote controls, so I've never built a parallel port JP1 circuit or tried to use one under any version of any OS. However, I don't see any problem using the RS-232 designs under any version of any OS, now or in the near future.

In fact, since the USB hardware depends on a driver (which, under Windows, is undoubtedly closed-source), it's the USB hardware that I'd be worried about continuing to work correctly with newer versions of Windows. Linux is usually much less of a problem because the drivers are all open-source and can be updated as needed.

And, unlike the USB design, I can use the RS-232 hardware interface designs in an RS-232 port or (with one of many suitable, inexpensive USB/RS-232 adapters) in any USB port as well -- that's the kind of flexibility that comes in handy at times.

And when we build an interface, we're not really "doing it ourselves", unless we write all of the relevant software, and design the circuit.

Now, maybe this was "tongue-in-cheek", but this part strikes me as downright silly. There are all sorts of levels of "DIY". What's next? Should I hang my head in shame because I bought the resistors and didn't wire-wind one or bake the carbon myself?

I would never look down on someone who didn't want to build their own hardware -- it's just not most people's "cup of tea". But, by the same token, those people should understand (and, fortunately, I think "3FG" does, based on the last sentence in his/her post) that there's also a great sense of accomplishment at times from "doing it yourself". As Craig ('csete') already noted, it's not about the cost.

I don't mean to clutter up the boards with my stories of failure... hopefully I don't sound like I'm whining too much and I'm definitely not pointing fingers at anyone else.

For the record, Craig, none of your posts to date have bothered me or felt inappropriate in the least. Please continue to update us on your progress (or lack thereof ) and I'll continue to do my best to provide whatever help I can.

Regards,
Bill

[vickyg2003]

Craig, please pursue this in what ever way makes this fun for you. Personally I have as little to do with the hardware side as I can, but if other people weren't "having fun" with the hardware where would the forum be.

[gfb107]

However, I don't see any problem using the RS-232 designs under any version of any OS, now or in the near future.

In fact, since the USB hardware depends on a driver (which, under Windows, is undoubtedly closed-source), it's the USB hardware that I'd be worried about continuing to work correctly with newer versions of Windows. Linux is usually much less of a problem because the drivers are all open-source and can be updated as needed.

And, unlike the USB design, I can use the RS-232 hardware interface designs in an RS-232 port or (with one of many suitable, inexpensive USB/RS-232 adapters

That's only because JP1.2+ uses true serial communication. JP1 uses i2c which is done by bit banging. That will not work with any sort of USB to Serial or Parallel adapter.

[WagonMaster]

That's only because JP1.2+ uses true serial communication. JP1 uses i2c which is done by bit banging. That will not work with any sort of USB to Serial or Parallel adapter.

Thanks for the clarification, Greg. (I actually knew that, but your post makes mine clearer.) In my mind, JP1 (EEPROM) is such a dead-end that I sometimes (unintentionally) mentally ignore it.

Bill

[The Robman]

In my mind, JP1 (EEPROM) is such a dead-end that I sometimes (unintentionally) mentally ignore it.

Careful there Billy, there's still quite a few of us old times that have JP1 (EEPROM) remotes that are ticking along just fine, and most of us have no intention of trading them in any time soon.

[WagonMaster]

Careful there Billy, there's still quite a few of us old times that have JP1 (EEPROM) remotes that are ticking along just fine, and most of us have no intention of trading them in any time soon.

True. The mental shortcoming is mine and I fully admit it.

Bill(y)

[3FG]

csete,
I really didn't mean to imply that you shouldn't post here, and I trust that you will continue.

I understand that DIY projects are fun. I've built telescopes, radios, remodeled the house, etc.

My point is: the only good reason to build a JP1.2/1.3 interface is for the fun of it.

[csete]

The fun may be subsiding on this project. I spent another couple of hours rebuilding the circuit from scratch today using all new components. I had what I considered a pretty nice layout of components with as few jumpers as possible (still a lot). I got it done and... it doesn't pass the jp1xtester test either. I ran the tests on my wife's laptop with Windows XP and a real live serial port to avoid as many complications as possible. I do see the power button blink twice indicating a reset occurred, but the tester reports no remotes found.

I was able to trace my way through the wiring and it looks correct to me. I have not had time to walk through the com_test.exe troubleshooting because we have company coming over, but I'm not hopeful it will give any more positive results. Until I have a chance to look a bit more closely, I'm hoping someone can answer a couple of questions that may or may not help. It is becoming obvious that I don't do this type of stuff often enough and I'm losing my memory on implementation of schematics.

- Is there any chance that jp1xtester would fail, but IR.exe would not? (I'm guessing not, but thought I'd ask)
- I've rechecked the wiring, but one thing I was unsure of was the polarity of the diodes. I have the non-black end of the diode wired to ground. Is that correct? I usually associated GND as being negative, but the wikipedia entry says the cathode is negative and makes me wonder if I've done the diodes backwards. If so, what are the chances that I've trashed them and need to replace them?
- I'm 99% certain I've oriented the transistors correctly... I've rechecked them a couple of times. The emitters go to GND, correct?
- What are the other things I can/should do to diagnose my issue if comtest fails too?

Given that I've failed to get this circuit working twice in a row, it really makes me think that I'm doing something stupid... twice!

Thanks again for all of your help on this.
Craig

[The Robman]

Maybe it's time for some pics?

[csete]

As long as everybody promises not to laugh... I will send something momentarily...