I need some code to run a RobotDyn LCD Keypad Shield 1602 16x2 Display Module for Arduino Uno - Blue. To work whit a wemos d1.
RobotDyn LCD Keypad Shield 1602 16x2 Display Module for Arduino Uno - Blue
I have it working on Arduino Uno but not not a wemos d1.
Maybe the 5volt LCD shield doesn't like a 3.3volt MCU.
Leo..
It is a wemos d1 whit 5V.
In case you are not aware, the Wemos boards use Dn pin mapping symbols for their labeled pins and you must use the Dn pin mapping symbol if you want to access the pin vs naked constants which is the norm in Arduino.
Naked constants in the esp8266 core refer to GPIO bit numbers and the GPIO bit numbers are not the same as the Dn pin symbol.
i.e to access the pin labeled D9 you must use D9 not the naked constant 9 as those are not the same pin.
Any LiquidCrystal example should work once you fill in the appropriate pins for the shield and use the Dn symbols.
--- bill
bob5731:
It is a wemos d1 whit 5V.
Yes, WeMos supply is 5volt.
But the chip runs on 3.3volt, so logic signals for the LCD shield are 3.3volt.
Leo..
The D1 will work with those shields. I have a few and while the logic signals on the esp8266 are only 3v they are high enough to work with the LCD.
From a s/w code perspective, nothing special is needed.
I have tested it with my hd44780 library package as well as the IDE bundled LiquidCrystal library.
I'm betting it is a simple initialization issue as the same constructor initialization in the sketch can not be used for both UNO and wemos D1 due to the Dn vs n pin issue.
--- bill