About DS18B20

[jerabaul29]

Need to:

• re-test
• document

[jerabaul29]

@TryggviLab I would need to spend a bit of time to clean up / document things around temperature measurements, but basically I have been using successfully some DS18B20 temperature sensors, up to 8, put on a "temperature sensor measurement string". Using waterproof ones, they can be deployed out of the enclosure, to measure temperature at different depths in the snow or water (for example, these work great: https://www.sparkfun.com/products/11050 ), which is quite valuable for us scientists :) . So definitely, adding some "easy to use" PCB traces would be great.

To attach them, I have used:

• powered mode (ie 3 wires rather than 2 wires parasitic mode)
• D4: 3.3V supply by digital pin, protected by typically 50 ohms to avoid shorting in case of a broken temperature sensor
• D35: signal, shared by all temperature sensors, protected by typically 50 ohm (same, to avoid shorting)
• GND
• pullup D35 to D4, using typically 4.7kOhm with 6 thermistors

So the circuit looks like the attached picture.

Typically, providing the traces on the carrier PCB, with the possibility to connect up to 8 temperature sensors (ie array of 8 GND, 8 PWR, 8 DAT, grouped "3 by 3 close to each others" so that the wiring / soldering is easy), but without the resistors (providing through holes spaces that the users can fill with the right value) would be amazing :) .