Valentine One to a PC

**drait** · 03-25-2005, 02:14 PM

Jim, if we were to get one of the MAX232 solutions that zPilott mentioned (I'm eyeing that nice AD232DB that fits in a DB-9 hood) would Software One work with it, or would there need to be any changes on that end?

Anyone know if there are 12v->5v regulators small enough to stuff into that hood? A 7805 might be too large.

**jimbonzzz** · 03-25-2005, 02:47 PM

It would be difficult to say for certain if that MAX232 design would work with my software. I've never messed with the MAX232 ICs, maybe if I had one to play with on the bench I could say for certain, but I would hate to point you guys in the wrong direction. If someone has one of these on hand, maybe they could try it?

Myself, I've only tested with a few different designs:

-The schematic on my page
-The CT-29 radio programming cable from http://www.rtsars.com, which is the same as the six-transistor design from here: http://home.comcast.net/~sllewd/pcware.htm
-The USB interface from http://www.TTL2USB.com

These are all the exact same circuits that are used with my radio programming software too, and I CAN say for sure that people have tried in the past to use the bare MAX232 design with the radios, and it hasn't worked without the additional inverting. But with the V1, I don't know for sure...

I'm planning on adding muting from software in the near future, probably utilizing the RTS or DTR line, so any interface will need modified for that as well.

Jim

**Saab9-5** · 03-25-2005, 04:04 PM

Originally Posted by drait

Anyone know if there are 12v->5v regulators small enough to stuff into that hood? A 7805 might be too large.

They make small - TO92 package, size of a 2N2222 transistor - and surface mount - SOT23 package, really tiny - voltage regulators. The SOT23 may be difficult to solder leads to and is limited in the amount of current it can handle. You can get them at Digikey among other places - just not Radio Shack.

**jimbonzzz** · 03-25-2005, 09:44 PM

Alright guys, I built another interface today (I was going to add the mute function). But, the interface had problems working, just like some of the problems posted here! The software never said "Error: Not Connected" however the screen remained blank. I did some probing and experimenting, and here's the result:

http://www.kc8unj.com/radar/v1_int_b.gif

After removing the 33Ks and the diode, it worked like a charm. I think the voltage on the base of the transistor never got low enough to turn it on completely. It might be a good idea to use a small value resistor off the base of the transistor, but I've been using it without. Hope this helps some of you out...

Also, here's a couple of pics on my interface, without the mute functionality (yet!). It isn't too pretty, built on a piece of Radio Shack perf board:
http://www.kc8unj.com/radar/intpic1.jpg
http://www.kc8unj.com/radar/intpic2.jpg

Jim

**tj!2k4** · 03-25-2005, 11:40 PM

Awesome!

I was always interested in electronics but never followed through and learned about it.. I really wish I knew how to read the interface cable schematic. =(

I'll spend some time examining this and see if I can't make some sense of it. Look out

here I come!!

**jimbonzzz** · 03-26-2005, 12:56 AM

I've been working on it some more...I've added mute support to the interface:
http://www.kc8unj.com/radar/v1_int_c.gif

I've also got muting/mode changing working in the software, and it will be available in the next release...

Jim

**tj!2k4** · 03-26-2005, 01:18 AM

Sorry if these are stupid questions, but...

1.) All grounds get connected together and start at the RJ11 Ground and wind up at pin 5 of the DB9, right?

2.) Can the 4k resistor to bypass the remote display module be connected at any point on the data circuit?

Thanks.. =)

**drait** · 03-26-2005, 01:54 AM

Originally Posted by tj!2k4

Sorry if these are stupid questions, but...

1.) All grounds get connected together and start at the RJ11 Ground and wind up at pin 5 of the DB9, right?

That's how I have my ground lines.

2.) Can the 4k resistor to bypass the remote display module be connected at any point on the data circuit?

Thanks.. =)

I would imagine it could be placed anywhere along the line. Probably easiest at either the V1 end or the PC interface end, but I suppose you could place it along the cable too.

**Arathranar** · 03-26-2005, 02:20 AM

Originally Posted by jimbonzzz

I've also got muting/mode changing working in the software, and it will be available in the next release...

Can you make the source available? That will make properly integrating it into the the Road Runner front end possible.

**drait** · 03-26-2005, 04:02 AM

Jim, following your update, I removed all the 33k's and the diode from the data line, replaced the 150 and 47k with 2%/5% pieces, and even swapped in a 4.7V zener in place of the 5.1V and I'm still getting a blank S1 screen.

Are there any test voltage values at various points throughout this design that I could verify?