Wiring up

A project log for RFID data logger

NodeMCU with RFID reader, SD card logger, and OLED screen

borazsloborazslo 03/07/2017 at 21:310 Comments

125Khz RFID module - NodeMCU: softwareSerial communication

+5V DC should be detached during firmware upload, because NodeMCU D3 is used also for FLASH.

SD Card SLOT - NodeMCU: SPI communication

128x32 OLED Display - NodeMCU: I2C communication

Buzzer - NodeMCU

NodeMCU D0 is used during flash of new firmware, so the buzzer needs to be disconnected during firmware update.

Please give me suggestions how to optimize these connections. How can I use for example A0, S3, S2, S1, SC, S0, SK, EN pins of NodeMCU?