Uno WiFi rev2 and I2C LiquidCrystal or Dallas temperature DS18B20


I bought this wifi card to upgrade a sketch runing fine on Uno rev3, using 3 DS18B20 and a LCD display to show results all along the loop

The wifi was to get time on a time server and allow exchanges server-client to show and modify parameters.

The wifi board stop working during a step of writing on the LCD display.

last writing was "Consigne" , new writing is "Ambiance" the result is "Ambsigne" and then the board stops working like in a very long delay().

I've red lots of thing about compatibility of old libraries without success.

In addition of these trouble, after trying to update megaAVR board using the board manager from 1.8.5 to the last 1.8.6, it becomes impossible to compile my program, the message is : in french "erreur de compilation pour la carte uno wifi rev2"

So i think that there is some incompatibility somewhere, but where ?

Hoping for your help

This is the message I get when I compile with 1.8.6 vers :

Arduino : 1.8.13 Hourly Build 2020/02/14 03:33 (Windows 10), Carte : "Arduino Uno WiFi Rev2, None (ATMEGA4809)"

In file included from C:\Users\Alain\Documents\Arduino\libraries\LiquidCrystal_I2C\LiquidCrystal_I2C.cpp:1:0:

C:\Users\Alain\Documents\Arduino\libraries\LiquidCrystal_I2C\LiquidCrystal_I2C.h:60:40: error: expected class-name before '{' token

class LiquidCrystal_I2C : public Print {


C:\Users\Alain\Documents\Arduino\libraries\LiquidCrystal_I2C\LiquidCrystal_I2C.cpp: In member function 'void LiquidCrystal_I2C::printstr(const char*)':

C:\Users\Alain\Documents\Arduino\libraries\LiquidCrystal_I2C\LiquidCrystal_I2C.cpp:256:2: error: 'print' was not declared in this scope



C:\Users\Alain\Documents\Arduino\libraries\LiquidCrystal_I2C\LiquidCrystal_I2C.cpp:256:2: note: suggested alternative: 'printf'




exit status 1 Erreur de compilation pour la carte Arduino Uno WiFi Rev2

Ce rapport pourrait être plus détaillé avec l'option "Afficher les résultats détaillés de la compilation" activée dans Fichier -> Préférences.