Do you run 5V? Do you connect sensor with +VCC (3 wires ) or parasitically (2 wires)? What pull-up resistor do you use?
Do you have access to scope to see waveforms?
P.S. Thanks, Merry Christmas to you too!!
Maybe your new shield is fighting with the temperature sensors.
The DS18B20's should be on a separate I/O pins - not shared with the SD card or RTC data lines?
Merry Christmas! We got snow and -23C tonight, so a chilly white Christmas.
The 5V supply and such is fine.
Just for curiosity, I've added a 12k resistor in parallel to the existing 4k7 resistor (3-wire connected sensor) which causes the whole mess to work again
At least for now. A endurance test is running....
read the one-wire comms datasheets.
the way you adress multiple devices without a clash is different to talking to a single one.
Watch long cable runs to the DS18B20's will need a lower (4k7 to 1k) pullup resistor and a 0.1uF decoupling cap across VDD and GND local at each temperature sensor for really good data.
the way you adress multiple devices without a clash is different to talking to a single one.
Yes, but this is not the problem, since I had a already working program on the destroyed Arduino.
Watch long cable runs to the DS18B20's will need a lower (4k7 to 1k) pullup resistor and a 0.1uF decoupling cap
As examined by my little experiment with the 12k resistor in parallel.
A decoupling cap at the sensor however seems like a good idea, to prevent any unexpected issues.
My endurance test went successfully so far. None of the sensors is replying "0.00" or even the error code "-127" since it was started.