Help needed with Wemos D1 mini

Firstly, apologies for a rather rookie question, I haven't been doing electronics for a decade or two. Now I got a Wemos D1 mini board, DFPlayer mini mp3 player and a SSD1306 OLED display (128x32) with I2C. I have managed to get either the DFPlayer or the OLED display to work with the Wemos board, but not both at the same time.

The problem is that I can't figure out how to connect them at the same time as they both seem to be working only when I connect them to pins D5 and D6 of the Wemos board (with DFPlayer: D5 -> RX, D6 -> TX, and with SSD1306: D5 -> SDA, D6 -> SCL). As far as I know, the DFPlayer doesn't support I2C so I can't just go and hook them together, can I? I tried the other pins as well but couldn't get anything out from either of the devices.

Pinout of the Wemos is: LOLIN D1 mini — WEMOS documentation

Just I have hard time understanding why can't I use the other pins than D5 and D6.

Can anyone give me any directions here?


The page you linked for the D1 Mini shows SCL on D1 (GPIO5) and SDA on D2 (GPIO4) and the RX/TX pins are dedicated (not D5/D6).
Do you still need Serial while connected to DFPlayer as using RX/TX pins will clash with Serial to PC.

Yes, I know that I should use D1/D2 for the OLED and RX/TX for the DFPlayer but the only way I could get Wemos to control DFPlayer or SSD1306 was using D5/D6. And yes, I obviously did change the code accordingly to use the pins the device was connected to.

Do you mean the RX/TX pins on Wemos or DFPlayer? I am not locked into any potential configuration as long as I could get all three of them connected and working together... :slight_smile:

This diagram is suggesting to connect DFPlayer through RX/TX: DFPlayer_Mini_SKU_DFR0299-DFRobot

Though, I see there are two ADKEY pins too. How do I use them?