1wire with propeller.

FORD

Does anybody out there know if 1wire will be happy with the 3.3 volt signal levels from a propeller ?

Cheers, Chris

Jon Williams

Yes, you can do it -- you'll just use a 3.3k pull-up.· The guys at Maxim/Dallas (when I was working with that DS1996 thing last year) told me to use about 1K per volt.·· I've been a bit swamped with other things, but have 1-Wire on my Propeller To-Do list.· I've attached a very old SX/B program (prior to 1-Wire commands being added to the language) that I wrote after working with the guys at M/D -- I'm going to convert this code to Spin ... if you don't do it first.

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Jon Williams
Applications Engineer, Parallax

FORD

Hello Jon, thanks for that, great to know that its still just a resistor required.

But mate... if you think I'm going to do that first, you are over estimating my ability by a long way.
I would love to do something like that and be able to offer it to everyone, but its beyond me in asm.
(I might·put some nice and simple ds1996 rd/wr code onto the stamp group at some stage to repay everyone for·help after I master it in spin though.)

I can do it no worries on a stamp, but asm is another thing.

Which brings to mind...
Another bonus in the propeller (for people like me who only really were able to get into microcontrollers because of the availability of stamps), is that we can start off with something in spin, and then try to improve it / speed it up by doing it in asm, all the while learning asm, but with a pattern to sort of follow, and still having something that works in spin if it all gets too hard. Being able to do the comparison on the same chip, and also run both types of code on the same chip will introduce a lot of people to asm that would never have gone there.

I think that the prop will be looked upon in years to come as having really opened up the microcontroller world on another level again. I must also say that this prop forum has really opened my eyes to some hardware information. When skilled programming / electronics people get on here asking, not answering questions, a lot of information rubs off to other people - fantastic.

Cheers,
Chris

Jon Williams

I'm not going to use Asm for my 1-Wire object, I'm going to use Spin. You can too!

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Jon Williams
Applications Engineer, Parallax

FORD

Jon,
I look forward to seeing whatever you build, I have started on some pulse counting routines with scale factors etc etc, and once I get the 4x20 display going (a few days before I can get to it), then I'm moving on to getting a good understanding of the full duplex stuff so that we can link keypads / modems etc.
You will have the 1wire stuff done a year before I could.

Cheers,
Chris

Jon Williams

Are you using a serial display? If so, I have a bunch of code you can drop in and use. I haven't written a parallel LCD object yet, but will shortly (with 4-bit and 8-bit routines).

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Jon Williams
Applications Engineer, Parallax

FORD

Hi Jon,
I am using a BPL-420 Seetron serial display, we prefer them because they have the large digit feature, with minimal code to set that up.
I would love to see any serial lcd stuff you have, in fact I'm just playing with changing your 216 lcd object to 420 as we speak.

Cheers,
Chris

Jon Williams

Well, since you're going through the trouble, let me give my latest code.· I spent some time over the last couple days making the Parallax serial LCD and SEETRON objects method compatible.

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Jon Williams
Applications Engineer, Parallax

FORD

Cheers, will let you know how it goes...

also nice to see you only working around 22 hrs a day !!

regards,
Chris