--- title: "W6300-EVB-PICO2でWifiClient-W6300.inoを動作する話" url: "https://maker.wiznet.io/matthew/projects/w6300-evb-pico2wificlient-w6300-ino/" markdown_url: "https://maker.wiznet.io/matthew/projects/w6300-evb-pico2wificlient-w6300-ino/md" type: "UCC: User Created Content" author: "Kazumasa Ueda" author_url: "https://zenn.dev/kazueda/articles/2c07552f1605c8" editor: "WIZnet" editor_url: "https://maker.wiznet.io/" original_author: "Kazumasa Ueda" original_url: "https://zenn.dev/kazueda/articles/2c07552f1605c8" published: "2025-12-16" language: "ja" likes: 0 views: 368 comments: 0 source: "WIZnet Makers (https://maker.wiznet.io/)" --- # W6300-EVB-PICO2でWifiClient-W6300.inoを動作する話 > ネットワーク接続を利用するプロジェクトを実行する場合、展示を想定して、有線でネットワークを作製するように心がけています。 Original author: Kazumasa Ueda (source: https://zenn.dev/kazueda/articles/2c07552f1605c8) ## Article ## [UCC Curation | JP] When `WiFiClient-W6300.ino` won’t work on W6300-EVB-PICO2: the minimum patch that makes it reproducible This is a curated, third-party-friendly summary of a **Japanese Zenn post** by **kazueda**. The original author tried the official Arduino example for **W6300-EVB-PICO2 (RP2350)**, but it failed to get online in their environment—so they modified the sketch and got **real Ethernet connectivity working end-to-end** (DHCP → TCP connect → payload read). --- ### 1. The problem this post solves: “the official example doesn’t work for me” ![](https://maker.wiznet.io/upload/ckeditor5/1052283358%5F1766356181%2Epng) Generate AI Image Following the official WIZnet Maker guide, you open `lwIP_w6300 → WiFiClient-W6300.ino`, build, and upload. In some setups, users get stuck because the sketch either: - never comes up on Ethernet (e.g., stuck waiting on DHCP / link), or - fails to connect out to the internet. The Japanese post is valuable because it doesn’t stop at “it didn’t work”—it isolates *why* and shows the smallest set of changes to make the demo reliable. --- ### 2. One crucial background detail: W6300-EVB-PICO2 is *not* a “standard SPI Ethernet module” The official guide explains that on W6300 boards the chip runs over **QSPI with fixed pin definitions** in the library (e.g., CS=16, SCK=17, IO0..IO3=18..21). That means “typical SPI module habits” (setting generic SPI pins, calling `SPI.begin()` like a normal SPI Ethernet board) can be misleading here. This single fact explains why a sketch that looks “normal” can still fail on this board. --- ### 3. Why it failed (as the author frames it): two root causes ![](https://maker.wiznet.io/upload/ckeditor5/1052283358%5F1766356365%2Epng) Generate AI Image The Zenn post effectively narrows failures to two points: #### A) Wrong chip-select argument → the chip isn’t actually selected If the CS value passed into the driver doesn’t match the board’s actual CS pin, the W6300 is never properly addressed. #### B) Treating QSPI hardware like standard SPI → unnecessary / confusing initialization Because the library already defines QSPI pins for W6300, leaving in “standard SPI setup” code can create confusion or unintended behavior. The author removes those SPI initialization fragments to match the QSPI-fixed reality. --- ### 4. The fix: the minimum patch that makes the example work ![](https://maker.wiznet.io/upload/ckeditor5/1052283358%5F1766356600%2Epng) Generate AI Image The strength of this post is how little it changes—just enough to make the demo **reproducible**. #### 4.1 Set CS explicitly to GPIO16 This is the “make-or-break” line. **Before** ```cpp Wiznet6300lwIP eth(1 /* chip select */); ``` **After** ```cpp Wiznet6300lwIP eth(16); ``` GPIO16 matches the board/library expectation for the QSPI CS line. #### 4.2 Remove standard SPI pin setup and `SPI.begin()` Since W6300 uses a QSPI path with fixed pins, the author removes code that tries to initialize the W6300 like a generic SPI Ethernet module. #### 4.3 Add a DHCP/link timeout (avoid infinite “hang”) Instead of waiting forever in loops like `while(!eth.connected())`, the author adds a ~10s timeout. This keeps the sketch responsive even if the cable/router/DHCP isn’t ready. #### 4.4 Handle “server closes early” correctly The demo connects to a QOTD server. Those servers may respond and close quickly, so only waiting on `available()` can cause pointless blocking. The author strengthens `client.connected()` checks so the loop exits cleanly when the server closes. #### 4.5 Clean up retry policy They tune the reconnect behavior: slow down once stable (e.g., 5-minute interval), but retry sooner after failures. That makes the demo friendlier in lab/demo setups while avoiding unnecessary load. *(The author also notes they used Copilot for parts of the changes—an honest “how it actually happened” detail.)* --- ### 5. What “success” looks like (how the post validates it) ![](https://maker.wiznet.io/upload/ckeditor5/1052283358%5F1766357027%2Epng) The patched sketch reaches a real end-to-end outcome: 1. Ethernet init → DHCP IP acquired 2. TCP connect to `djxmmx.net:17` (QOTD) 3. Receive and print the quote 4. Detect “server closed connection” and continue without hanging This is a strong validation pattern because it proves more than “link up”—it proves **real outbound TCP + payload read**. --- ### 6. Practical checklist for other users If you’re trying to reproduce the result, these are the high-impact checks: - You’re using the intended example: `lwIP_w6300 → WiFiClient-W6300` - CS is set to `16` (`eth(16)`) - You removed generic SPI initialization (QSPI fixed pins are already defined for W6300) - DHCP/link wait loops have a timeout - Client loops handle “server closed” cases correctly --- ### 7. Original language & author context (why this JP post is worth curating) - The source is a **Japanese Zenn article**, posted as part of **Raspberry Pi Advent Calendar 2025**. - The author describes themselves as someone who likes **8-bit CPUs and MCUs**. The key advantage of this kind of JP UCC is that it’s a real “I tried, it failed, here’s the minimal patch” record—exactly the thing that helps other users avoid the same trap. --- ### References - Original (JP): Zenn article by kazueda - WIZnet Maker Guide: Arduino example + QSPI pin notes for W6300 - WIZnet Docs: W6300-EVB-PICO2 overview --- Source: https://maker.wiznet.io/matthew/projects/w6300-evb-pico2wificlient-w6300-ino/