Re: 1-wire to USB converter that can use 1820s directly

["Rod Speed" <rod.speed.aaa@xxxxxxxxx>]

Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote
> Rod Speed <rod.speed.aaa@xxxxxxxxx> wrote
>> Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote
>>> Byron Hynes <bph@xxxxxxxxxxxxx> wrote

>>>> I think you have two choices:
>>>>  1. Purchase an engineered set of matching products, such as those
>>>> in the links below; or
>>>>  2. Build your own.

>>>> In order to do #2, you will need to understand more about the
>>>> 1-wire protocol and wiring options than you seem to do at present.
>>>> Have you read all of the appnotes and forum posts at the
>>>> Dallas/Maxim site?

>>>> I have four temperature sensors (DS18s20) currently logging using
>>>> this:
>>> http://www.electronickits.com/kit/complete/meas/ck110.htm

>>>>> The problem is that
>>>>> http://www.hobby-boards.com/catalog/product_info.php?products_id=108
>>>>> implys that you cant just add a swag of 1820s in parallel to
>>>>> http://www.hobby-boards.com/catalog/product_info.php?products_id=1503

>>> Here's a third, choice that solves the multiple string problem.
>>> This assembled board is available for ~$55 via PayPal from Dr. Peter
>>> Anderson

>>> http://www.phanderson.com/iom135.html

>>> I have one and can recommend.

>> Trouble is that it isnt USB.

>>> It is designed to read and control *eight* strings ("runs") of
>>> 1-wire temperature,

>> And it must be possible to do a USB/1-wire converter that operates
>> the same way.

>>> dual 32-bit counters and  quad-input 12-bit analog input devices.

>> Dont need those. And it makes more sense in my
>> situation to use 1-wire devices for that sort of stuff.

>>> Nothing else comes close to the versatility and low cost

>> Thats arguable given that a USB/1-wire converter that can
>> drive a string of 1820s should cost about $30 fully assembled.

>>> -- and for a good cause (helps Dr Anderson's students).
>>> Dr Anderson also sells many other devices including a
>>> USB -> RS-232 converter if you need it.
>>> www.phanderson.com

>> Yeah, I've used him in the past, just
>> doesnt have what I need in this case.

> Your quest seems to have evolved, post by post into

Only in the sense that if I cant find a USB/1-wire converter/adapter
that provides enough 1-wire power to be able to run a decent string
of bare 1820s, it makes more sense to beef up the 1-wire sting
power with a bog standard USB/1-wire converter/adapter than to
do anything else.

> a) multiple 1-wire channels (= "runs" = "strings")

Nope, I never said that. A single one of Pete's strings would be all I
need.

> b) controlled/read via USB

That was in the original.

> c) "should cost" =< than $30

Never said that.

> d) price including  software "drivers"

Or that.

> e) in a single pre-constructed device
>   (i.e., not USB-->RS232 converter + RS232--> 1-wire).

That was in the original too.

> f) you do/don't want 1-wire devices that aren't temperature sensors

Never said that.

> Which gives (me) the impression that you'd
> rather pose the problem than solve it.

More fool you.

> Peter's excellent, affordable solution is
> an 8-channel USB-RS-232 + PIC-> 1-wire.

Makes more sense to beef up the 1-wire sting power
with a bog standard USB/1-wire converter/adapter

> Maxim also makes the DS2482 IC2-> 8 channel 1-wire IC,
> but one has to get from the PC to the IC2 interface which
> requires at least one more chip to meet your stated need.

I clearly said that I want to run a string of 1820s in the original
and its clear from Pete's system that that is trivial to do.

> There aren't any 1-chip, USB->1-wire with
> multiple channels at this time as best I know.

See above

> Since you added the requirement of $30 cost
> late in your evolving explanation of needs,

No I didnt.

> consider buying 8 of your (hypothetical?) $30/channel,
> one channel USB->1-wire converters for a cost of $240.

Makes more sense to beef up the 1-wire sting power
with a bog standard USB/1-wire converter/adapter

If that is actually necessary. It may well be that a string of 1820s
would work fine on the bog standard USB/1-wire converter/adapter

And that is essentially what I was asking, whether
anyone had done that and found it worked fine.

> Peter's actual (not hypothetical) solution of USB -->RS-232 + PIC
> --> 8 channels 1-wire might be more attractive to you in that context.

Nope, I only need just one of his strings.

> Eight DS2490 USB to 1-Wire Bridge Chip's might fit in your budget but
> you wrote that you wanted something that was already constructed (
> and so ditto with the DS2482-800 Eight-Channel 1-Wire Master).

> (Fer hoots re-read your posts and responses for:

> 1) the inconsistency(ies) between what you wrote in
> your original post and your response above (2 points)

> 2) the pertinent fact(s) about PHAnderson's offerings
> that you misunderstand/represent (2 points) and

> 3) the additional requirement(s) you added
> after the original post requirements (2 points).

> Seven points gets you a 'B' ;-)

Thanks for that completely superfluous proof of
what a terminal fuckwit you have always been.