Multi DS18B20 (Onewire) with two separate Arduino

Other Hardware Sensors
1

Hello

Is it possible to read multi DS18B20 (on shared Onewire) with two separate Arduino ?

Thanks
Armen

2

Hi,

Hmm... MayBe..

ButWhy? How far apart are the Arduinos? Can they just send the data to each other on Software Serial etc??

IF the Arduinos are within a meter or so, AND you can coordinate, one could take the pin to "input" and let the other one talk to DS18B20's with the same pullup resistor.

What are you trying to accomplish??

3

Hi Terry
Not more distance , just for backup.
If one Arduino failed in temp detection , the other one work.
or for fast reading each sensor distribute some of them to Arduino A and others to B
I think reading time will be reduce in this model.
how can communicate this two Arduino with together trough serial ?
Thanks
Armen

4

It all seems rather pointless, particularly your second reason. If fast reading really is a problem, it's more likely to be time to think about using a different sensor than adding an extra Arduino.

5

If one Arduino fails it might take out the one-wire bus with it.

You intuition about fast reading is wrong, the sensors have a maximum read speed for
each precision setting.

Arduino's are very reliable, they are just a couple of microcontrollers, they don't fail unless
the power's bad or the code's bad.

6

How fast do you need the readings to be? With proper coding, you can request that all sensors do a temperature conversion at the same time. Reading them after that doesn't take long.

Why are you concerned about failures?

Pete

7

Hi All

Thank you for reply's!

Honestly there is concerned about sensor failures (delay or fail) that I like expand it to system.

in temperature if first sensor in Arduino1 show wrong data I should have a redundancy sensor to check first one with Arduino 2 sensor.

another problem :

when I compile program using this headers:
#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>
#include "Dns.h"
#include <Wire.h>
#include <RTClib.h>
#include <SPI.h>
#include <SD.h>
#include <LiquidCrystal.h>

for function of: NTP, RTC, Onewire (Multi DS18B20), LCD and Ethernet / SD (toggle switch in using time)
to get data from Internet web service and send data to web service (+ log it on SD for backup)
I get memory error
so I need to remove unused function or find other way to pass memory problem.
I don't know Arduino IDE is intelligent compiler or not (I ask in Programing)
another Idea is split program between 2 Arduino to split program and create communicate between together for all benefits.
So I need to search and find a way for solve this problems.
It would be very great full if send me suggestions or sample used all headers in one program (by url) Thanks
Armen

8

I get memory error

What is the EXACT error message?

Note, discussion on the memory 'problem' seems to have been moved to here: Is it Arduino IDE intelligent ? - Programming Questions - Arduino Forum

9

I try.. work one sensors on two separate arduino.....