hi guys:
I am doing a project that is working with multiple DS18B20. Som Times I get -196.60 F as temperature result. It's not correct value. I wonder what cause it and is there any solution for it?
Check your wiring. Do you use a breadboard with bad contacts ? Are your wires too long ?
The error "DEVICE_DISCONNECTED" results into a temperature of -196.6 F
Peter_n:
Check your wiring. Do you use a breadboard with bad contacts ? Are your wires too long ?The error "DEVICE_DISCONNECTED" results into a temperature of -196.6 F
I solder them. but the problem still showing up.
It sounds like DEVICE_DISCONNECTED is not the same as no device connection.
MikeLuo:
It sounds like DEVICE_DISCONNECTED is not the same as no device connection.
Really? It sounds exactly the same to me. You're getting -196.6, how much more proof do you need?
when I unplug it. the temperature wouldn't show up. When things are plug in, some times the data will show up.
Tell us about your wires, voltages, which Arduino board, perhaps mains wires running along the OneWire cable, and so on.
MikeLuo:
some times the data will show up.
Sometimes implies intermittently bad connection.
This is an Arduino forum so it would have been better to be more explicit about the Arduino. As it is, your system is running on 3.3v. The pullup resistor 4.7k is used on the assumption of a 5v Arduino, so maybe the problem lies there. The socket wiring looks rather fanciful but, so long as no data line is grounded, it should be OK
I don't know about the jack connectors. Are those 3.5" jack connectors ? I have a few good 3.5" jack connectors which need some force to plug into, and I have a box with many bad quality 3.5" jack connectors.
Are both the connectors and the plugs gold plated ?
You could do a test by soldering one of the DS18B20 directly to D5 pin and let that run for a while.
The 'connectors' that I often use for sensors are normal pcb board pins with the black headers (like the headers on the Arduino Uno). I solder the pins to a prototype board and I cut a piece from the black header and solder wires to that. It has been relyable so far.
We would like to see your sketch and tell us which library you use.
Since the timing is important, interrupts have a big influence on the timing. Perhaps you copied some code from the internet which is not okay.