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

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

This thread is a good instantiation of the rise
to hegemony in usenet of the lower quartile ...

Wota fucking wanker you are Hult.

To summarize:

To lie, actually.

1) The four-conductor RJ-11 plugs that the original poster
suggests are conventional and useful for 1-wire installation.

I never ever said anything of the sort. I JUST said
that that was the approach I PLANNED TO USE.

Basically because the wire is more flexible and convenient.

However 8-conductor RJ-45 plugs and jacks are ubiquitous
so they would seem preferable in many situations

Not in the PARTICULAR situation I WANT TO USE THEM IN.

especially considering that dependable whole-house 1-wire
distribution sh/would best consist in multiple channels (see below).

Separate matter entirely to what I was talking about.

A 4-conductor RJ-11 plug fits into a RJ-45 jack, so RJ-45
patch panels, available for less than $1/jack on eBay,

True in spades of RJ-11 panels.

provide a flexible, dependable, inexpensive solution that is
adaptable wiring infrastructure needs other than 1-wire (audio
signals, audio control, RS-232, video, computer network, and so on).

Irrelevant to what I want to do with the temperature sensors.

2) Twisted-pair wiring (eg CAT3, CAT5) is
preferred to non-twisted-pair especially if a
whole house is to be wired as the OP proposes.

Pity I wasnt even discussing whole house wiring.

The twisted pair provides better immunity to noise
and more constant impedance than the ("satin")
telephone wire suggested by the OP.

I wasnt even discussing satin telephone wire.

The use of non-twisted pair wiring such as what is connected
to the telephone cables that the OP proposes seems to be
asking for poor performance if used for 'long' distances.

Pity I'm not using them for long distances.

Also note that some phone cords are stranded and may
include cloth-like fibers making them difficult to solder

Which might be why I choose to avoid using those.

and durn near impossible to punch down

Dont need to punch those down, I clearly said that I want
to take commercially made RJ11 phone cords, cut them
in half and solder on a 1820 to each of the cut ends.

What I use for the RJ11 sockets those
plug into is an entirely separate matter.

(and so are potentially unreliable for these reasons).

See above.

3) Best practices for Maxim/Dallas 1-wire does not include
multiple channels (= "strings" = "runs") on a single driver.

I dont give a flying red *** what is 'best practices'.

I know that strings of 1820s work fine, particularly in the situation
where most of the 1820s are reasonably clumped together.

However the OP perserverates

That isnt even a word, you posturing fuckwit.

on this topology, perhaps because he under the mistaken
impression that the only issue is available power for the sensors.

Nope, because I have enough of a clue to realise that it works fine
for Pete Anderson and its documented in the Dallas datasheets too.

T'aint. Others has suggested that he inform himself by reading
the 1-wire documentation, but that doesn't seem to be his MO.

Best get that seems machinery seen to then Hult.

4) Maxim has a DS2482 IC that is designed to drive multiple channels.

I dont want multiple channels.

Dr Peter Anderson www.phanderson has developed and sells nifty,
inexpensive PIC-based systems that also drive multiple channels.

And clearly advocates the use of strings of 1820s.

OP has been repeated referred to these resources by respondents,

I was well aware of that before I even posted thanks.

It doesnt happen to be what I want.

but doesn't seem to 'get it'.

You dont seem to get that strings work fine, Pete Anderson uses them
fine, and so all I need is a USB/1-wire converter/adapter which drives
strings of 1820s the same way that device of Pete's does, or add that
to a commercial USB/1-wire converter/adapter myself.

5) Despite what OP writes, Dr Anderson's site does indeed
include schematics and explanations for the devices in question.

Yeah, its just rather poorly organised.

6) Despite the OP's imperviousness to the concept that USB, RS-232,
1-wire and I2C all involve serial communication and that real devices
(whether in one package or not) necessarily involve translation
betwixt them, a USB --> RS-232 converter + PIC--> multi-channel
1-wire solution (such as Dr. Anderson's) would meet his need.

Not as well as a commercial USB/1-wire converter/adapter
which will drive the 1-wire the same way Pete does in his system.

The multi-channel IC offering from Maxim/Dallas has I2C input
and so needs a USB front end to met the OP's needs.

I dont need multichannel. Like that or lump it.

7) Despite what the OP now claims, reasonable people reading
carefully would conclude that he is looking for a pre-built device
that includes software drivers for about $30 or less.

Only fools like you. ALL I said was that since commercial
USB/1-wire converter/adapters are available for less than
$25, one which drives the 1-wire string like Pete's does
power wise shouldnt result in a price more than $30.

I am also considering using a much more expensive
lan/1-wire device. Its got some advantages like being
more convenient to integrate with VBA into Access and
Excel since its a standard http protocol device etc, but
has some potential downsides with other than just
1820 support and is rather less flexible in that area.

I don't know of any that are multi-channel

I dont want or need multichannel.

and am reluctant to recommend a single
channel implementation of what he proposes.

I dont actually give a flying red *** what
you might or might not recommend.

Clearly Pete Anderson has decided that strings of 1820s work fine.

It could be done, of course, by daisy chaining each of the strings
through
a hub, ( IN1-->OUT2 -->IN2-->OUT3-->IN3 etc) but it simply isn't worth
the aggravation of a flakey data acquisition system in my opinion.

Your opinion is completely irrelevant. Pete Anderson
is clearly of the opinion that strings of 1820s are viable.

The cost difference of $20 or so is small compared
even to the price of the sensors required by the
system. When one also considers consequences of
errors and time expended, the cost difference is trivial.

There are no cost consequences of errors.
Or time expended either in this case.

Among other reasons, a single break or poor connection
in a daisy chained system takes down the entire system.

It isnt daisy chained, the sensors are PARALLELED.

Multiple drivers and channels ("strings") isolate problems,
are more robust than a single channel and are easier to
trouble-shoot and generally more reliable.

Not interested. I'm quite capable of trouble shooting
a break in the paralleled config I plan to use.

Daisy chained aint what I want, basically because that involves
a pair of wires to each sensor location. A star config makes much
more sense given where the sensors will be located, in clusters.

8) It is generally trivial to adapt an RS-232 device to USB using an
inexpensive adapter. This has been suggested by several respondents,
but apparently rejected by the OP for whatever reason.

Because it makes more sense to do something extra
on the 1-wire side of the USB/1-wire converter/adapter
if it wont drive the string of 1820s adequately.

9) In the experience and opinion of many (myself included)
the most readily accessible programming interface for
1-wire is an simple ASCII protocol that the hardware
device understands such as those used by Dr. Anderson.

I prefer to do it better myself. Essentially because
that give more control with other 1-wire devices later.

This allows the hardware device to deal
with 1-wire timing and electrical issues.

Thats what the USB/1-wire converter/adapter does.

The OP wants a USB "driver" for VBA,

I didnt say that.

Excel etc (whatever he means by that).

Three good, very different approaches/sources for communicating with
1-wire-aware devices are 1) Homeseer with plugs, 2) www.windmill.co.uk
and
3) StampPlot www.selmaware.com (I've used them all and can recommend.)

Not what I asked about. I want to be able to control the strings from
access and excel.


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