---
title: "W55RP20 EVB PICO"
url: "https://maker.wiznet.io/forum/15878"
markdown_url: "https://maker.wiznet.io/forum/15878/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Roland"
created: "2025-09-15T15:47:40+09:00"
last_activity: "2025-09-17T08:30:43+09:00"
language: "en"
tags: ["Arduino"]
views: 6
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W55RP20 EVB PICO

## Question

Asked by Roland on 2025-09-15 in Ethernet Chips.

I´m using your code WIZnet W55RP20-EVB Pico

Trying to work with I2C.

Example1 in the attachment is to get temperature from an AHT10

I tried to connect to the AHT10 over SDA GP14 (Pin19) and SCL GP15(Pin20) of the Board.

**When using  **
*Wire1.setSDA(19);***
*Wire1.setSCL(20);*
*Wire1.begin();*

The Chip hangs up…

Example2 in the attachment is to get temperature from an SHT21

Both are compiling, but no data from the temperature sensor

*...cannot dwell there long."*

*George Bernard Shaw (1856-1950)*

*closing connection*

*TEMP: -46.8*

In example 2:
SDA is connected to Pin GP0 (Pin1) of the W55RP20-EVB-PICO

SCL is connected to Pin GP1 (Pin2) of the W55RP20-EVB-PICO

Gnd and 3V3

May anyone can help me on this?

## Replies

### Reply 1 by Lihan__, 2025-09-17

First of all, the pin number appears to be incorrect

The W55RP20 is a SiP chip combining the RP2040 and W5500. Referring to the RP2040 datasheet to check each GPIO function will likely help you when configuring the pins.

---

> I tried to connect to the AHT10 over SDA GP14 (Pin19) and SCL GP15(Pin20) of the Board.

If you want to control GP14 and GP15, you should write the code as follows.
(It should not be configured based on the pin numbers of the W55RP20-EVB-Pico board.)

```c
 Wire1.setSDA(14);
Wire1.setSCL(15);
```

---

> SDA is connected to Pin GP0 (Pin1) of the W55RP20-EVB-PICO
> SCL is connected to Pin GP1 (Pin2) of the W55RP20-EVB-PICO

In addition, if you’d like to set it up as described in Example2, you can configure it as shown below.

```c
 Wire1.setSDA(0);
Wire1.setSCL(1);
```

---

This link may be helpful as a reference.

rp2040 Datasheet
<https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf> - 13p

W55rp20 Datasheet

<https://docs.wiznet.io/img/products/w55rp20/W55RP20_ds_v100e.pdf>

Wiznet docs - W55RP20-evb-pico

<https://docs.wiznet.io/Product/ioNIC/W55RP20/w55rp20-evb-pico>

---

Source: https://maker.wiznet.io/forum/15878