Ethernet

The ESP32 supports Ethernet in two different ways:

Using the ESP32 for the MAC layer but with an external chip for the PHY layer, using RMII.
Using an external chip for both the MAC and PHY layer, using SPI.

External PHY chip

A few different chips are supported, as indicated below.

PHY Chip	Available since	Argument
IP101	v1.4.0	`-p model.ethernet.phy.chip.ip101=1`
LAN8720/LAN8710	v1.4.0	`-p ethernet.phy.chip.lan8720=1`

To connect to an external PHY chip using RMII, there are some essential configurations to consider depending on the layout.

Option	Default	Argument
PHY address	Auto detect	`-p model.ethernet.phy.addr=<addr>`
PHY Reset pin	No reset pin	`-p model.ethernet.phy.reset=<pin>`
RMII MDC pin	GPIO 23	`-p model.ethernet.mac.mdc=<pin>`
RMII MSIO pin	GPIO 18	`-p model.ethernet.mac.msio=<pin>`

In additional to these variable options, there is a set of fixed pins that must be kept unused. That includes GPIO 0, 19, 21, 22, 25, 26 and 27.

Only boards with an external reference clock connected to GPIO 0 are supported.

ESP32 Ethernet Kit V1.2

The official ESP32-Ethernet-Kit has a built in IP101 chip.

This particular layout use pin 5 as PHY Reset. The rest are kept as the default. To install Toit on this device, the following arguments can be used.

toit serial reinstall \
  -p ethernet=1 \
  -p model.ethernet.enabled=1 \
  -p model.ethernet.mac.chip.esp32=1 \
  -p model.ethernet.phy.chip.ip101=1 \
  -p model.ethernet.phy.reset=5

External MAC chip

When an external MAC chip is used, it's communicated with using a dedicated SPI bus.

A few different chips are supported, as indicated below.

MAC Chip	Available since	Argument
WizNet W5500	v1.4.0	`-p model.ethernet.mac.chip.w5500=1`

To connect to an external MAC chip using SPI, there are some essential configurations to consider.

Option	Argument
SPI MOSI	`-p model.ethernet.mac.mosi=<pin>`
SPI MISO	`-p model.ethernet.mac.miso=<pin>`
SPI Clock	`-p model.ethernet.mac.sclk=<pin>`
SPI CS	`-p model.ethernet.mac.cs=<pin>`
Interrupt pin	`-p model.ethernet.mac.int=<pin>`

Industrial Shields 10 IOs PLC

The Industrial Shields 10 IOs ESP32 device has a built in WizNet W5500 MAC/PHY chip.

toit serial reinstall \
  -p ethernet=1 \
  -p model.ethernet.enabled=1 \
  -p model.ethernet.mac.chip.w5500=1 \
  -p model.ethernet.mac.sclk=18 \
  -p model.ethernet.mac.miso=19 \
  -p model.ethernet.mac.mosi=23 \
  -p model.ethernet.mac.cs=33 \
  -p model.ethernet.mac.int=39

MAC address

The ESP32 comes with an allocated Ethernet MAC address that by default will be used by both internal and external MAC configurations.