Info on UIRT2?

[jon_rhees]

All,

I personally would avoid long serial cables, but your results may vary. Since the PIC is performing 115,200 baud using a 'bit-banging' technique, baud timings are not exact *in addition to* there is no oversampling on the UART. This puts things on the edge, and will vary from PC to PC, etc.

-Jon

[Luc]

Yes, Jon's firmware will work. What problems did you experience with it on Ruud's hardware. Wich versions and remote did you use?

The lenght of the wires: I did not yet test "extra long" but don't expect problems with the emitters, these are high power driven. There will be problems for the receiver depending on the environment and lenght of cable, the data signal is high impedance and will be influenced by disturbances etc..
How long would your cables be?

The last question is almost impossible to answer, if no errors are made during assembly and programming it should work immediatly. I will include assembly documentation and if this is followed everything should be ok.

Regards,
Luc.

[Luc]

I just received an updated firmware version from Jon, I will test it on Monday. This one should solve possible communication problems between the UIRT and PC.
I don't see a reason why a "A" pic wouldn't work, I will try one and also test with a "looong" RS232 cable.

[Luc]

Everything works just fine: a PIC16F84A-20P with the new 10MHz firmware from Jon and a 12m serial cable. :D
The long serial cable doesn't make much sense for my design because you need other cabling to the PC as well unless you take power from somewhere else.
But at least this proves that there are no problems in this area.

Luc.

[Antti]

Hi!

Okay. Now the UIRT2 looks like it's ready to be assembled but before I begin I would like to know a couple of things. First, is it an "absolute fact" that Jons firmware will work? With my UIRT (from Ruuds page) only Danijels 10Mhz version works. Any real life experience with this?

And then about the wires. How long can they be approx.? Like how many metres or feet from the jack to the IR-receiver or emitters? Any difference with shielded or unshielded wire?

And last but no least. If something goes wrong while assembling or programming the chip what's the most obvious reason?

Wishes,

Antti

[Antti]

Yes, Jon's firmware will work. What problems did you experience with it on Ruud's hardware. Wich versions and remote did you use?

All other firmware versions than Danijels just gave me that "No 'OG' or 'OK' reply" or something like that. I believe that I tried almost every version of firmware that I could find. Danijels v1.22 is the only working one. And this is with UIRT1. BTW. I just tried Jons fw yesterday with Danijels programmer to be sure and it didn't work. My PIC is 16F84A. Something wrong with the A-version?


How long would your cables be?

With this UIRT1 that I have the cable is about 2m. But it's between serial port and PCB. Not between PCB and emitters/receiver. Maybe the length just has to be tested. Easier to cut the cable shorter than to add some. :)

Antti

[Antti]

Everything works just fine: a PIC16F84A-20P with the new 10MHz firmware from Jon and a 12m serial cable. :D

Geez.. Not that long.. :) . And I didn't really mean the serial cable because I'm planning to build the 'B'-version. I was wondering about those cables from UIRT to emitter and receiver. I suppose I'll build one this weekend. And now I know I can use the PIC from UIRT1. Nice. Wish me luc(k). Heh.

Antti