Pin mapping for wiring DS18B20 to XLR?

[angrybits]

I googled for this, but I couldn't find anything definitive. Is there a convention already in place for systems that use DS18B20's with XLR connectors? I realize I can do whatever I want but if I can follow convention then that would be my preference.

 

[jmark]

I just wired up a bunch of these for my brewpi rebuild and looking at the solder connection side, I wired the bottom left red and bottom right black with the top yellow (data). Like you said, you can wire them any which way... just keep a note!

 

[day_trippr]

I use 3 terminal locking mini-XLRs that have an alignment keyway that bisects two of the pins.
With over two dozen probes in various services I needed a standard of some kind, if totally arbitrary.

With the keyway at 12 o'clock and looking into the pin side of a receptacle I wire the top left pin to VDD, the top right pin to GND and the bottom pin to the signal.

I haven't seen many folks using the same mini-XLR connectors, perhaps as they are a bit pricey, even when sourced via eBay.
The current favorite termination seems to be RJ11's (which have their own arbitrary wiring scheme )

Cheers!

 

[mattd2]

I use 3 terminal locking mini-XLRs that have an alignment keyway that bisects two of the pins.
With over two dozen probes in various services I needed a standard of some kind, if totally arbitrary.

With the keyway at 12 o'clock and looking into the pin side of a receptacle I wire the top left pin to VDD, the top right pin to GND and the bottom pin to the signal.

I haven't seen many folks using the same mini-XLR connectors, perhaps as they are a bit pricey, even when sourced via eBay.
The current favorite termination seems to be RJ11's (which have their own arbitrary wiring scheme )

Cheers!

Any chance you could let me (us) know which ebay seller you use?

 

[day_trippr]

Sure! Fortunately eBay saves purchase history back a couple/few years, and it appears I bought nearly all of the plugs and receptacles from 2010-nature
http://www.ebay.com/usr/2010-nature?_trksid=p2057872.m2749.l2754

Good vendor - never had any problems...

Cheers!

[edit] I use the TA3F SA3X243 plugs

and SA3X292 receptacles.

 

[angrybits]

Thanks for the input, all. The prototyping carries on..

 

[mattd2]

Sure! Fortunately eBay saves purchase history back a couple/few years, and it appears I bought nearly all of the plugs and receptacles from 2010-nature
http://www.ebay.com/usr/2010-nature?_trksid=p2057872.m2749.l2754

Good vendor - never had any problems...

Cheers!

[edit] I use the TA3F SA3X243 plugs

and SA3X292 receptacles.

Cheers day tripper. Is everyone using female plugs and male panel mount sockets? Just wondering about the convention to not use males on the live side of a plug/socket - or is that convention not applicable when using under 24vdc?

 

[crane]

With this low of voltage you won't get shocked unless you lick it, and even then it's just a tickle. XLRs are most commonly used for microphone cables. They always have used them with the female on the cable and the male side in the mic/preamp.

 

[jmark]

Yeah, I didn't even give it any thought... I have male panel mounts.

 

[augiedoggy]

Yeah, I didn't even give it any thought... I have male panel mounts.

Same here... They are recessed too so.

 

[day_trippr]

Same here... They are recessed too so.

Exactly. Neither gender has (mechanically) exposed pins this way.
Shouldn't be running more than low voltage stuff through them though.

Cheers!

 

[mattd2]

Thanks guys - thought that to be the case

 

[angrybits]

If anyone was curious, I went with:

Pin 1 - GND
Pin 2 - Vdd
Pin 3 - Signal

I strapped a 220nF cap across Pin 1 and 2.

 

[swimIan]

Did this work for you in the end? I have a panel mount xlr from
auber used for a RTD and a PID. I was thinking of repurposing the panel mount and buying Auber's ds18b20 sensor.

 

[angrybits]

Did this work for you in the end? I have a panel mount xlr from
auber used for a RTD and a PID. I was thinking of repurposing the panel mount and buying Auber's ds18b20 sensor.

TL;DR - Yes, my first test was successful.

To expand a bit, I am just using ebay audio xlr cords to connect to the probes. I also soldered and potted my own probes sourced from Mouser because I wanted to make sure they were real and within the specs in the datasheet. I have 6-8" of cord and a female xlr on the end for the probe, then I just use commodity audio cables to get from the probe to the panel.

My first test went really well using proportional-only control in a brewhardware.com rims tube on a 120V line. It came up to temp and then very slightly oscillated by a couple tenth's of a degree.

I have had nothing but good luck using Auber EZBoils and PT100 probes. In this case though, I'm using custom software from the microcontroller all the way to the cloud. RTDs are hard/expensive to deal with so I punted to DS18B20's. Using digital sensors allowed me to concentrate less on analog circuitry (which seems a bit quirky) and more on software, so that is why I went that direction.

 

[mattd2]

TL;DR - Yes, my first test was successful.

To expand a bit, I am just using ebay audio xlr cords to connect to the probes. I also soldered and potted my own probes sourced from Mouser because I wanted to make sure they were real and within the specs in the datasheet. I have 6-8" of cord and a female xlr on the end for the probe, then I just use commodity audio cables to get from the probe to the panel.

My first test went really well using proportional-only control in a brewhardware.com rims tube on a 120V line. It came up to temp and then very slightly oscillated by a couple tenth's of a degree.

I have had nothing but good luck using Auber EZBoils and PT100 probes. In this case though, I'm using custom software from the microcontroller all the way to the cloud. RTDs are hard/expensive to deal with so I punted to DS18B20's. Using digital sensors allowed me to concentrate less on analog circuitry (which seems a bit quirky) and more on software, so that is why I went that direction.

Any chance you can share the process/pictures for the DIY probes?

 

[angrybits]

Sure, the next time I have to make them I will try to remember to get a YouTube video made from it. It's pretty simple in theory, but soldering the leads can be tricky.

 

[thekraken]

Any chance you can share the process/pictures for the DIY probes?

+1.

@angrybits, You mentioned putting a capacitor across vcc and ground? What's that about? I know we put a resistor across vcc and data.

 

[angrybits]

+1.

@angrybits, You mentioned putting a capacitor across vcc and ground? What's that about? I know we put a resistor across vcc and data.

My understanding is that a cap across a DC line can do much for smoothing it out, so my aim is to quiet the Vdd line and try to keep the wires from becoming an antenna. The shielding on the XLR cable will hopefully make up for any short comings in my theory.

(disclaimer: not an engineer, please correct me if I am wrong about any of this)

 

[bheinecke]

This is a little off the topic from the OP's question but ... here it goes...


If your system allows for a bit of a medusa you can bring back all of the DS18B20 to a single XLR connection. The admittedly terrible picture shows 15 wires coming in from 5x DS18B20 to a terminal block then leaving the other side of the box as 3 wires. This intermediate box is just a collector for the sensors to reduce wiring complexity later downstream.

I will be using a 5 pin XLR connection to my control box. With this single connection I will have 5x DS18B20 and 1x analog pressure sensor (sharing ground). Search "5-Pin XLR Panel Mount Connector 16mm (10 Pack)" on amazon. Going for $18 right now.

 

[angrybits]

I will be using a 5 pin XLR connection to my control box. With this single connection I will have 5x DS18B20 and 1x analog pressure sensor (sharing ground). Search "5-Pin XLR Panel Mount Connector 16mm (10 Pack)" on amazon. Going for $18 right now.

Neat trick, thanks for sharing.

 

[crane]

My understanding is that a cap across a DC line can do much for smoothing it out, so my aim is to quiet the Vdd line and try to keep the wires from becoming an antenna. The shielding on the XLR cable will hopefully make up for any short comings in my theory.

(disclaimer: not an engineer, please correct me if I am wrong about any of this)

It's not so much that it prevents the wires from becoming antennas, but it does help to stabilize the Vdd voltage rail with respect to ground.