meshtastic_firmware/variants/rp2350/diy/wiznet_5500_evb_pico2_e22p

WIZnet W5500-EVB-Pico2 + E22P-868M30S - Meshtastic Variant

Meshtastic support for the WIZnet W5500-EVB-Pico2, a Raspberry Pi Pico 2 development board with an integrated W5500 Ethernet PHY on SPI0, paired with an external EBYTE E22P-868M30S LoRa module on SPI1.

This variant is hardware-twin of pico2_w5500_e22 (same LoRa pinout, same W5500 pin mapping) but targets the WIZnet PCB rather than a standalone Pico 2 + external W5500 module. The two key differences are:

	pico2_w5500_e22	wiznet_5500_evb_pico2_e22p
Board target	rpipico2 (4 MB flash)	wiznet_5500_evb_pico2 (2 MB flash)
W5500 PHY	External breakout module (you wire it)	Integrated on the PCB (hard-wired)

⚠️ Flashing a W5500-EVB-Pico2 with the pico2_w5500_e22 env builds for a 4 MB flash target and can silently overflow the 2 MB available on the WIZnet PCB. Use this variant for the WIZnet board.

The LoRa wiring and variant.h are shared with diy/pico2_w5500_e22 via -I variants/rp2350/diy/pico2_w5500_e22 - there is no duplicated pinout file.

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Required Hardware

Component	Model	Notes
Board	WIZnet W5500-EVB-Pico2	RP2350 @ 150 MHz, 512 KB RAM, 2 MB flash, on-board W5500
LoRa	EBYTE E22P-868M30S	SX1262 + 30 dBm PA, 868 MHz (Europe band); RFEN combines LNA + PA enable lines

The W5500-EVB-Pico2 carries a smaller Q-SPI flash (2 MB) than a stock Pi Pico 2 (4 MB). The board target wiznet_5500_evb_pico2 selects the correct flash size so the linker fails fast if the image overflows, instead of producing a UF2 that gets truncated when flashed to the device.

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Pinout

System pins (W5500-EVB-Pico2, fixed by the PCB)

GPIO	Function
GP24	VBUS sense - HIGH when USB is connected
GP25	User LED (heartbeat)
GP29	ADC3 - VSYS/3, measures supply voltage

W5500 Ethernet (SPI0, on-board)

W5500 signal	RP2350 GPIO
MISO	GP16
CS / SCS	GP17
SCK	GP18
MOSI	GP19
RST	GP20
INT	GP21
VCC	3.3V
GND	GND

All Ethernet pins are wired by the PCB - nothing to solder. SPI0 is reserved for the W5500.

E22P-868M30S LoRa (SPI1, external)

E22P signal	RP2350 GPIO	Notes
SCK	GP10	SPI1 clock
MOSI	GP11	SPI1 TX
MISO	GP12	SPI1 RX
NSS / CS	GP13	Chip select
RESET	GP15	Active LOW reset
DIO1	GP14	IRQ interrupt
BUSY	GP2	Module busy indicator
RFEN	GP3	Combined LNA + PA enable - held HIGH at all times
TXEN	← DIO2	Bridge on the module (see below)
VCC	3.3V	Add a 100 µF capacitor close to the module
GND	GND	-

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E22P vs E22 - what changed

The E22P-868M30S is the newer revision of EBYTE's 30 dBm 868 MHz module. The pinout is interchangeable with the E22-900M30S but the RF switch control differs:

• On the older E22-900M30S, RXEN enables the LNA and TXEN enables the PA (two separate pins).
• On the E22P-868M30S, both functions are merged into a single RFEN pin acting as a global RF enable. RFEN must be held HIGH whenever the radio is active - both during RX and TX.

The firmware drives this with SX126X_ANT_SW 3, which sets GP3 (RFEN) HIGH once at boot and leaves it there. TXEN switching during transmit is still handled by the on-module DIO2 → TXEN bridge (see below).

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Special wiring: DIO2 → TXEN bridge on the E22P module

The E22P-868M30S does not connect DIO2 to the TXEN pin of its PA internally. They must be bridged with a short wire or solder bridge on the module itself:

E22P DIO2 pin  ──┐
                 ├── wire / solder bridge on the module
E22P TXEN pin  ──┘

With this bridge in place, SX126X_DIO2_AS_RF_SWITCH causes the SX1262 to drive DIO2 HIGH automatically during TX, enabling the PA without needing an RP2350 GPIO for TXEN.

Without this bridge the module will not transmit.

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Build

pio run -e wiznet_5500_evb_pico2_e22p

Flash - BOOTSEL mode

1. Hold the BOOTSEL button on the W5500-EVB-Pico2.
2. Connect USB to the PC - it appears as a RPI-RP2 storage drive.
3. Copy the .uf2 file:

.pio/build/wiznet_5500_evb_pico2_e22p/firmware-wiznet_5500_evb_pico2_e22p-*.uf2

Or directly with picotool:

pio run -e wiznet_5500_evb_pico2_e22p -t upload

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Network usage

This board uses Ethernet (no Wi-Fi). From the Meshtastic app:

• Enable Ethernet under Config → Network → Ethernet Enabled
• DHCP by default; static IP can also be configured

Services available once connected:

Service	Details
NTP	Time synchronization
MQTT	Messages to external broker
API	TCP socket on port 4403
Syslog	Remote logging (optional)

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Technical notes

LoRa - RF control

Define	Effect
SX126X_ANT_SW 3	GP3 (RFEN) driven HIGH at init and never toggled again
SX126X_DIO2_AS_RF_SWITCH	SX1262 drives DIO2 HIGH during TX → enables TXEN via bridge
SX126X_DIO3_TCXO_VOLTAGE 1.8	E22P TCXO controlled by DIO3
-D EBYTE_E22_900M30S	Sets TX_GAIN_LORA=7, max power 22 dBm

Ethernet

• Library: arduino-libraries/Ethernet@^2.0.2 (supports W5100/W5200/W5500 auto-detection).
• SPI0 is explicitly initialized with pins GP16/18/19 before Ethernet.init().
• DHCP timeout is set to 10 s (instead of the default 60 s) to avoid blocking LoRa startup.

HW_VENDOR

Mapped to meshtastic_HardwareModel_PRIVATE_HW - no dedicated model exists in the Meshtastic protobuf for this hardware combination.