ESP8266 Community Forum

Posted: **Sat Jul 18, 2015 6:44 am**

martinayotte wrote:That's why the specs mentionned using a mosfet directly to VCC ...
(But of course, on software side, it is a bit more complex since you need to cut that supply before receiving the data)

I tested the system with different resistor values, and I managed to read up to 3 sensors. (R = 0.76k). I just have to buy MOSFET

Thank You

Posted: **Sat Jul 18, 2015 11:46 am**

This problem may base on the fact that the esp is only 3.3v instead of 5 v. Try to connect the Pullup to 5v and wire 2 pairs of antiparalell diodes between the Sensors string/pullup and the digital io of the ESP to get a data bus voltage level of at least 4.5V. Good luck!

Posted: **Sat Jul 18, 2015 12:02 pm**

Good point !
Maybe it is an issue that WStan is facing.
I have some other projects using also 3.3V MCU as well, but I'm using a bidirectional level-shifter one those.

Posted: **Sat Jul 18, 2015 3:07 pm**

wififofum wrote:Use requestTemperaturesByAddress instead.

Have you tried this?

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