seadoggie01
Posts: 7
Joined: Wed Jul 24, 2019 9:52 pm
Location: Florida, USA

DS18B20 Sensor

Wed Jul 24, 2019 10:23 pm

Hello,

First time poster here, but anyways :)

I'm looking for a DS18B20 sensor for a thermostat project. I'm annoyed that the stores online have really decent prices for ~10 pieces and 'meh' ones for singles, but I understand business is business. Anyways, if someone has an extra laying around, I'd be happy to pay shipping and cost for it.

If there are no responses by next Saturday (August 3rd) I'll be ordering a 10 pack :) Feel free to comment/email if you want me to ship you one (I think personal messages are disabled, so hmu at chandler j mclean at gmail dot com if you want to remain anonymous). I'll send it to you for whatever shipping costs!

Thanks!
Seadoggie01

P.S. I saw some weird looking ones... (here). If you know if they work, let me know too!

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 7456
Joined: Wed Dec 04, 2013 11:27 am
Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: DS18B20 Sensor

Thu Jul 25, 2019 12:25 pm

seadoggie01 wrote:
Wed Jul 24, 2019 10:23 pm
P.S. I saw some weird looking ones... (here). If you know if they work, let me know too!
They'll work - they're the bare sensor in a TO-92 package instead of the waterproof variant. You'll need to solder onto the package legs.

You haven't provided your location therefore responses may be limited. One could guess the USA based on your use of amazon.com, but that doesn't necessarily follow.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

seadoggie01
Posts: 7
Joined: Wed Jul 24, 2019 9:52 pm
Location: Florida, USA

Re: DS18B20 Sensor

Thu Jul 25, 2019 4:54 pm

6by9 wrote:
Thu Jul 25, 2019 12:25 pm
They'll work - they're the bare sensor in a TO-92 package instead of the waterproof variant. You'll need to solder onto the package legs.

You haven't provided your location therefore responses may be limited. One could guess the USA based on your use of amazon.com, but that doesn't necessarily follow.
Thanks! And also for the location tip, I've updated it :)

JohnsUPS
Posts: 125
Joined: Fri Jul 06, 2018 2:13 am
Location: USA

Re: DS18B20 Sensor

Mon Jul 29, 2019 1:46 am

If you're inclined to order a bunch of these, I would strongly suggest that you order them from a reputable dealer like Digi-Key, Mouser or Jameco who surely source directly from Maxim/Dallas. I ordered a couple of ten packs from China (from two different vendors), and each time received parts that were probably counterfeits because the calibrations were way off. I connected five together (all in parallel and in the same thermal environment), and some were off by more than three degrees of each other (way out of spec). In reading these forums, I am not the only person who has encountered these less-than-expected quality parts in a quest to save a few bucks.
I spent a couple extra dollars for legitimate parts (in my case Mouser), and they tracked/mirrored each other within the data sheet tolerance when I tested them.
I suppose if you have access to a way of calibrating them, you could calculate offsets but then linearity and reliability come into play.

danjperron
Posts: 3408
Joined: Thu Dec 27, 2012 4:05 am
Location: Québec, Canada

Re: DS18B20 Sensor

Mon Jul 29, 2019 2:58 pm

Please note that your wires will conduct heat so use wires longer than 20 cm away from the Pi. The Pi itself will transfer the heat to the sensor and through the wires from the connector by conduction.

Return to “Wanted”