Arduino for STM32

thanks all, finally I can overcome this issue by changing the wire cable of my sensor
I just cut it off and replace it with the new one

mrburnette wrote: Thu Jan 14, 2021 1:34 pm Are you "really" supplying +5V from DC-DC to the 3.3V uC as shown in the schematic?

yeaaa

fpiSTM wrote: Thu Jan 07, 2021 9:14 am Tested too on several boards with different MCU and it works.
I guess it is more a wiring issue (resistor?).
You can also try with https://github.com/PaulStoffregen/OneWire

I have tried this, but the output sometimes -127 and sometimes 85

PB5 - I copied and pasted your code without any modification.
+------+
| Vcc |---+-----+------> 3.3V
| | | |
| | | | | 4.7K resistor
| | | |
| Data |---------+------> PB5
| | |
| | ---
| | --- 0.1uf capacitor
| | |
| GND |---+------------>GND
+------+
DS18B20 Mine is one of those waterproof ...

From
https://forum.arduino.cc/index.php?topic=201863.msg1488781#msg1488781
There is a footnote on page 4 which says "The power-on reset value of the temperature register is +85°C."
so if you read 85 degrees it means it hasn't done a conversion since the last power on.
You hadn't wired it up ...

Sorry, it might be late. I still working on this issue. I have tried to change my PCB design too but still can't overcome this issue. Anyway, I have tried in a breadboard, and same as you guys it worked as well. I don't know why it doesn't work on PCB, I did the same wiring as I did on a breadboard ...

which pin are you using?

I'm using a temperature sensor DS18B20 with STM32F103 Bluepill, but sometimes this sensor gives me 85°C which is the power-on reset value of the temperature register. I'm so confused because sometimes it can give me the correct value but mostly is 85°C. I have put a 4.7K resistor as the pull-up ...

can we use this OneWireSTM library if our core is Arduino_STM32 core (not the rogerclark one)?

so nice of you guys, thank you it's solved. I was wrong choosing my board part number
I have made a little change to my code above in case someone needs it