ESP types

Comparison

	Flash	RAM	PSRAM
ESP8266
ESP-01	ext. 1MB	80kB
Wemos D1 Mini	ext. 4MB	80kB
NodeMCU
ESP8265
ESP-01	int. 1-2MB
ESP32
WROOM based	4MB	520kB (328k usable)	0MB
ESP32-mini	4MB	520kB	0MB
Lolin32	4MB	520kB	0MB
ESP32 DevKit v1	4MB	520kB	0MB
WROVER based	4MB	520kB	8MB

ESP8266

• Pinout
  • ESP-01: [1]
  • Wemos D1 Mini: [2]
  • NodeMCU: [3]

Pin Priorities

Pin		I2C	SPI	ESP-01	D1 Mini	Comment	Boot behaviour
GPIO14	D5		SCK		x
GPIO12	D6		MISO		x
GPIO13	D7		MOSI		x
GPIO5	D1	SCL			x
GPIO4	D2	SDA			x
GPIO16	D0				x	Pulldown resistor	high on boot
GPIO15	D8		CS		x		Boot failure if high
GPIO0	D3			x	x		Boot failure if low
Inputs
ADC	A0				x	Analog input
Serial
GPIO1	TX			x	x	TX	high on boot, failure if low
GPIO3	RX			x	x	RX	high on boot
Strapping Pins (Boot)
GPIO2	D4			x (LED)	x		high on boot, boot failure if low

ESP32

• Pinout
  • ESP32-mini: [4]
  • Lolin32: [5]
  • ESP32 Devkit v1 (30pin): [6]
  • ESP32 Devkit v1 (38pin): [7]

• WROVER = 8MB PSRAM

Pin Priorities

Pin		ADC1	DAC	RTC(WakeUp)	Touch	SPI	Comment
IO04				x	x
IO05						CS
IO16
IO17
IO18						CLK
IO19						MISO
IO23						MOSI
IO25			x	x
IO26			x	x
IO27				x	x
IO32		x		x	x
IO33		x		x	x
IO12				x	x	HSPI	(Platform IO JTAG)
IO13				x	x	HSPI	(Platform IO JTAG)
IO14				x	x	HSPI	(Platform IO JTAG)
IO15				x	x	HSPI	(Platform IO JTAG)
Input only
IO34		x		x			Input only
IO35		x		x			Input only
IO36		x		x			Input only, Hall
IO39		x		x			Input only, Hall
Serial, I2C, SPI
IO1							TX
IO3							RX
IO21							I2C SDA
IO22							I2C SCL
Strapping Pins (Boot)
IO0				x			Boot button
IO2				x			Block flash
IO5							?
IO15							Low = no boot log
Flash Chip
IO06
IO07
IO08
IO09
IO10
IO11