Inky PHAT and 18b20 temp. sensor(s)

Discussion Raspberry Pi
1

Hi. I am not sure this is the right place to post this question, but I’ll try anyway…

Here’s what I would like to achieve; measure temperature using one or more (waterproof) 18b20 sensors operating in 1-wire mode, and display the temperatures on an Inky PHAT.

I got it working for a while, but suddenly when I do
ls /sys/bus/w1/devices/
with one sensor connected to the 3V3, GPIO4 and ground pins, I get output like
00-400000000000 00-800000000000 w1_bus_master1

Is there some compatibility issues with the Inky PHAT and these sensors? I’ve spent a lot of time on this already, thinking that it would be really simple to do what I want. It seems not though, maybe I’m doing something wrong?

2

The Inky pHat pinout is here

I do believe One Wire uses BCM4 GPIO 7 so I don’t see any obvious conflict.

3

Thanks. It looks like I should double-check my wiring and soldering then…

4

“How do you have it wired up” was going to be my next question?
As the Inky wants to be plugged in on top of the GPIO.
Not that it matters, but what model Pi?

5

It seems like I’m experiencing something similar to what is described in this thread: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=161977&p=1564518#p1564518

I don’t know how to move on from here. It feels like I’ve wasted a lot of time, and learned nothing, which really annoys me.

6

I have yet to do anything on onewire so I can’t help much with that. All my sensors are i2c.
What is the sensor in / measuring?

7

It’s measuring 0 degrees Celcius, if that’s what you mean? (and obviously, it’s not 0 degrees in the room which I’m in).

8

No I meat is it measuring the ambient air temperature or maybe immersed in a liquid? If its something other than water it may be why the sensor fails? Chemical reaction or corrosion?

9

I see. No, the sensor was on my desk. There are no signs of corrosion. I haven’t submerged them into any liquids, or had them in humid conditions.

So, it’s just confusing to me.

10

Ok, I seem to remeber some issues with certain chemicals posted on the Adafruit forum. Something like that, was a while ago. I’m also at a loss as to what’s going on?