nodeMCU v3 PN532(nfc) NFC App(ai2) on android phone, comm. the ndef ms...

SDA(tx) SCL(rx) nodemcu

อ้างอิง
http://www.hoaglun.com/blog/2013/1/27/i2c-lcd-challenge

What is SDA and SCL?
SDA = TX Data
SCL = RX Data (Clock) 



nodeMCU
martinayotte wrote:The default pins are defined in variants/nodemcu/pins_arduino.h as SDA=4 and SCL=5, but those are not pins number but GPIO number, so since the pins are D1=5 and D2=4.
Anyway, you can also choose the pins yourself using the I2C constructor Wire.begin(int sda, int scl); - See more at: http://www.esp8266.com/viewtopic.php?f=13&t=10374#sthash.Ahy4UbNy.dpuf

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