esp32s3-eth programming setup guide

This commit is contained in:
Wyatt Marchand
2026-08-26 09:28:47 -07:00
parent 5e9d5d6404
commit 8d2c30ca73
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End-to-end setup for a Waveshare ESP32-S3-ETH board (W5500 ethernet over SPI), using the `std` Rust toolchain (`esp-idf-svc`). By the end you'll have a project that connects to ethernet, gets a DHCP lease, and is structured to build real functionality on top of.
This walkthough was AI generated
---
## 0. Hardware reference
Confirm these against your board's silkscreen before wiring anything extra — Waveshare's pin assignments have varied slightly across production batches.
|Signal|GPIO|
|---|---|
|SCLK|13|
|MOSI (SDO)|11|
|MISO (SDI)|12|
|CS|14|
|INT|10|
|RST|9|
|SPI host|SPI2|
|SPI clock|2025 MHz|
The W5500 has no burned-in MAC address — you supply one in software (any locally-administered address, e.g. `02:00:00:12:34:56`, works).
---
## 1. Prerequisites
- USB-C cable, board connected to your dev machine.
- ~5GB free disk space (toolchain + ESP-IDF + submodules).
- Linux/macOS/WSL. (Windows native works too but paths below assume a POSIX shell.)
- `git`, a C compiler, `python3`, and standard build tools already on the system (`build-essential` on Debian/Ubuntu, or equivalent).
---
## 2. Install the Rust + Espressif toolchain
```bash
# Rust itself, if not already installed
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
# espup: installs the Xtensa-patched Rust toolchain ESP32-S3 needs
cargo install espup
cargo install ldproxy
espup install
# Load the Xtensa toolchain into your shell (needed every new shell)
. $HOME/export-esp.sh
```
Add the `. $HOME/export-esp.sh` line to your shell rc file (`.bashrc`/`.zshrc`/`config.fish`) so you don't have to re-run it manually every session.
Verify the Xtensa target is present:
```bash
rustc --print target-list | grep xtensa
```
You should see `xtensa-esp32s3-none-elf` and similar in the output.
---
## 3. Scaffold the project
Use `esp-idf-template`, **not** `esp-generate` — the latter scaffolds `no_std`/`esp-hal` projects, which have no W5500/ethernet driver and no standard HTTP server story.
```bash
cargo install cargo-generate
cargo generate esp-rs/esp-idf-template cargo
```
You'll be prompted interactively. Answers for this board/use case:
|Prompt|Answer|Why|
|---|---|---|
|Project name|your choice||
|MCU|`esp32s3`|matches this board|
|Configure advanced options?|Yes|need to reach the STD toggle below|
|STD support|**Yes**|pulls in `esp-idf-svc`; without this you're back on `no_std`|
|ESP-IDF version|`v5.3.4`|most stable match to current esp-idf-svc/hal crates; avoid `master`|
|Use git (not crates.io) esp-idf-* crates|**false**|crates.io releases are stable and documented; git HEAD drifts underneath you|
|Installation location of managed ESP-IDF|**global**|shared across projects, avoids re-downloading ~12GB per project|
|Configure Dev Containers?|false|flashing real hardware over USB is simpler done natively|
|Configure Wokwi simulation?|false|Wokwi doesn't model the W5500/ethernet peripheral|
|Add CI files?|false|add later if/when you push to GitHub|
This produces:
```
your-project/
├── .cargo/config.toml
├── Cargo.toml
├── build.rs
├── rust-toolchain.toml
├── sdkconfig.defaults
└── src/main.rs
```
---
## 4. Confirm the generated build target
Open `.cargo/config.toml` and confirm:
```toml
[build]
target = "xtensa-esp32s3-espidf"
```
If this is missing or wrong, `cargo build` will silently try to compile for your host machine instead of the chip and fail with `Unsupported target 'x86_64-unknown-linux-gnu'` (or similar). The template sets this correctly by default — just verify it.
---
## 5. Configure sdkconfig.defaults
Edit `sdkconfig.defaults` (created empty or near-empty by the template) to include:
```
CONFIG_ETH_SPI_ETHERNET_W5500=y
CONFIG_ESP_MAIN_TASK_STACK_SIZE=8000
CONFIG_HTTPD_MAX_REQ_HDR_LEN=1024
```
The first line is required — without it, ESP-IDF doesn't build the W5500 driver component in at all, and your ethernet code will fail to link or fail at runtime. The other two are reasonable general-purpose values (headroom for the main task stack, generous HTTP header limit if you add a server later).
---
## 6. Configure Cargo.toml
Replace the `[dependencies]` section with at minimum:
```toml
[dependencies]
esp-idf-svc = { version = "0.51", features = ["std"] }
anyhow = "1"
log = "0.4"
```
Add more crates as your project needs them — see the companion note on porting non-embedded dependencies if you're bringing code over from another platform.
---
## 7. First build (this installs ESP-IDF itself)
```bash
cargo build --release
```
The **first** build does a lot of one-time work: downloads ESP-IDF, sets up a Python virtualenv, installs `xtensa-esp-elf`, `esp-clang`, `cmake`, `ninja`, and more. Expect this to take 1020+ minutes and several GB of downloads. Subsequent builds are fast.
### Known first-build failure points
These are common enough to check for proactively rather than debug blind:
**a) `esp-clang: error while loading shared libraries: libxml2.so.2`** Rolling-release Linux distros (Arch-based, etc.) ship a newer libxml2 soname than the pinned esp-clang binary expects. Fix:
```bash
ldconfig -p | grep libxml2 # find your installed version, e.g. libxml2.so.16
sudo ln -s /usr/lib/libxml2.so.16 /usr/lib/libxml2.so.2 # adjust path/version to match
sudo ldconfig
ls -la /usr/lib/libxml2.so.2
```
The final command should show a symlink of libxml2.so.2 to libxml2.so.16
**b) `Missing esp-mqtt submodule` / CMake `git_submodule_check` errors** The managed ESP-IDF checkout needs its git submodules initialized (several components are submodules even if your project doesn't use them):
```bash
cd .embuild/espressif/esp-idf/v5.3.4
git submodule update --init --recursive
cd -
cargo build --release
```
If that's still broken, delete and let it re-clone fresh: `rm -rf .embuild/espressif/esp-idf/v5.3.4`.
A successful build ends with a normal `Compiling <your-project>` / `Finished release` output.
---
## 8. Write a minimal ethernet-only main.rs
This is the "ready for proper code" checkpoint — confirms SPI, the W5500, and DHCP all work before you build real functionality on top:
```rust
use std::thread;
use std::time::Duration;
use esp_idf_svc::eth::{BlockingEth, EspEth, EthDriver, SpiEthChipset};
use esp_idf_svc::eventloop::EspSystemEventLoop;
use esp_idf_svc::hal::peripherals::Peripherals;
use esp_idf_svc::hal::prelude::*;
use esp_idf_svc::hal::spi::{config::DriverConfig, Dma, SpiDriver};
use log::info;
fn main() -> anyhow::Result<()> {
esp_idf_svc::sys::link_patches();
esp_idf_svc::log::EspLogger::initialize_default();
let peripherals = Peripherals::take()?;
let sysloop = EspSystemEventLoop::take()?;
let pins = peripherals.pins;
let spi_driver = SpiDriver::new(
peripherals.spi2,
pins.gpio13, // SCLK
pins.gpio11, // MOSI
Some(pins.gpio12), // MISO
&DriverConfig {
dma: Dma::Auto(4096), // required — default (no DMA) can't move full ethernet frames
..Default::default()
},
)?;
let eth_driver = EthDriver::new_spi(
spi_driver,
pins.gpio10, // INT
Some(pins.gpio14), // CS
Some(pins.gpio9), // RST
SpiEthChipset::W5500,
20.MHz().into(),
Some(&[0x02, 0x00, 0x00, 0x12, 0x34, 0x56]), // locally-administered MAC
None, // default PHY address
sysloop.clone(),
)?;
let eth = EspEth::wrap(eth_driver)?;
let mut eth = BlockingEth::wrap(eth, sysloop)?;
info!("Starting eth...");
eth.start()?;
info!("Waiting for DHCP lease...");
eth.wait_netif_up()?;
let ip_info = eth.eth().netif().get_ip_info()?;
info!("Got IP: {:?}", ip_info);
loop {
thread::sleep(Duration::from_secs(1));
}
}
```
---
## 9. Flash and verify
```bash
cargo install espflash # one-time, if not already installed
cargo build --release
espflash flash --monitor target/xtensa-esp32s3-espidf/release/<your-project-name>
```
If Linux user needs permission for port access:
```shell
sudo usermod -aG uucp $USER # Arch Systems
sudo usermod -aG dialout $USER # Debian Systems
```
Then reboot.
Watch the serial monitor. Success looks like:
```
I (...) esp_idf_svc::eth: Driver initialized
I (...) hello_eth: Starting eth...
I (...) hello_eth: Waiting for DHCP lease...
I (...) hello_eth: Got IP: ...
```
If it hangs after "Waiting for DHCP lease..." with repeating `w5500.mac: w5500_spi_write failed` / `w5500_spi_read failed` errors in the log, the SPI bus doesn't have DMA enabled — double check the `Dma::Auto(4096)` line in step 8 is present.
If it hangs with no errors at all and no IP, check physically: ethernet cable plugged into a live switch/router port, link LED on the RJ45 jack lit.
---
## 10. You're ready to build on this
At this point you have a project that: builds for the correct target, links the W5500 driver, brings up ethernet, and gets a DHCP lease. From here, typical next additions:
- An HTTP server (`esp_idf_svc::http::server::EspHttpServer`)
- GPIO for LEDs/buttons/sensors (`esp_idf_svc::hal::gpio::PinDriver`)
- SPI/I2C peripherals sharing the bus alongside the W5500 (own CS pin, same or different SPI host)
- Async networking (`tokio`, `async-nats`, etc.) — needs additional rustflags and feature trimming; see the note on porting non-embedded async code if relevant to your project
---
## Quick-reference: build error → fix
|Error|Cause|Fix|
|---|---|---|
|`Unsupported target 'x86_64-unknown-linux-gnu'`|`.cargo/config.toml` target missing/wrong, or Xtensa toolchain not loaded in shell|Check `target = "xtensa-esp32s3-espidf"`; re-run `. $HOME/export-esp.sh`|
|`esp-clang: ... libxml2.so.2`|Host libxml2 soname mismatch|Symlink to your installed version (§7a)|
|`Missing esp-mqtt submodule` / CMake errors|Managed ESP-IDF checkout missing submodules|`git submodule update --init --recursive` in the IDF checkout (§7b)|
|`txdata transfer > host maximum` / w5500 read/write failures|SPI DMA disabled|`Dma::Auto(4096)` in `DriverConfig`|
|`EthDriver::new_spi` argument/type errors|API differs across esp-idf-svc versions|Match the compiler's reported signature exactly, not older examples/tutorials|
|No W5500 driver at runtime|`CONFIG_ETH_SPI_ETHERNET_W5500=y` missing from sdkconfig.defaults|Add it, rebuild|
@@ -1,196 +0,0 @@
Working setup, derived from an actual first-time bring-up. Every failure mode below was hit and fixed, in order. Follow this straight through and you skip all of it. (AI generated)
## Board reference
Waveshare ESP32-S3-ETH — ESP32-S3 + onboard W5500 ethernet chip over SPI (not RMII — there's no on-chip MAC/PHY involved, W5500 has its own MAC and does everything over SPI).
Confirmed pin mapping (verify against your board's silkscreen — Waveshare pin assignments have varied slightly across production batches):
|Signal|GPIO|
|---|---|
|SCLK|13|
|MOSI (SDO)|11|
|MISO (SDI)|12|
|CS|14|
|INT|10|
|RST|9|
|SPI host|SPI2|
|Clock|2025 MHz|
W5500 has no burned-in MAC address — you must supply one (a locally-administered address like `02:00:00:12:34:56` works fine).
## Why std (esp-idf-svc), not no_std (esp-hal)
`esp-generate` scaffolds `esp-hal` (`no_std`) projects. That toolchain has no W5500/ethernet driver and no full HTTP server story — its focus is Wi-Fi/BLE via `esp-radio` and `embassy`. For ethernet + a standard HTTP server, use the `std` toolchain via `esp-idf-svc`, which wraps ESP-IDF's C ethernet driver and httpd component.
**Rule of thumb:** if the board has W5500/LAN8720/other wired-ethernet hardware, use `esp-idf-template` (std). Reach for `esp-generate` (no_std) only for pure Wi-Fi/BLE projects.
## 1. Toolchain
```bash
espup install
. $HOME/export-esp.sh # re-run in every new shell, or add to your shell rc
```
Confirm the Xtensa target is present:
```bash
rustc --print target-list | grep xtensa
```
## 2. Scaffold the project
Do **not** use `esp-generate`. Use:
```bash
cargo install cargo-generate
cargo generate esp-rs/esp-idf-template cargo
```
Prompt answers that matter:
|Prompt|Answer|Why|
|---|---|---|
|MCU|`esp32s3`|matches the board|
|Configure advanced options|Yes|need to reach STD toggle|
|STD support|**Yes**|pulls in `esp-idf-svc`; this is the whole point|
|ESP-IDF version|`v5.3.4`|most mature crates.io compatibility; avoid `master`/newest unless you have a reason|
|Use git esp-idf-* crates|**false**|crates.io releases are stable and documented; git HEAD drifts mid-project|
|Install location|**global**|ESP-IDF toolchain reused across projects, saves re-downloading (~12 GB)|
|Dev Containers|false|flashing real hardware over USB is simpler done natively|
|Wokwi simulation|false|Wokwi doesn't model W5500/ethernet peripherals|
|CI files|false|add later if/when you push to GitHub|
## 3. Known environment issues and fixes
These hit in this order on a fresh Arch-based system (Omarchy); adjust distro-specific commands as needed, but expect similar issues on any non-Ubuntu-LTS host.
### a) `esp-clang: error while loading shared libraries: libxml2.so.2`
Rolling-release distros ship a newer libxml2 soname (`.so.16`+) than the pinned `esp-clang` toolchain expects (`.so.2`). Symlink it:
```bash
ldconfig -p | grep libxml2 # find your installed version, e.g. libxml2.so.16
sudo ln -s /usr/lib/libxml2.so.16 /usr/lib/libxml2.so.2 # adjust path/version to match
sudo ldconfig
```
Verify against the actual binary, not just `ldconfig -p` (which may not reflect symlinks immediately):
```bash
/path/to/.embuild/espressif/tools/esp-clang/*/esp-clang/bin/clang --version
```
If a failed build already deleted the tool directory during its own error-recovery, just rebuild — `cargo build` reinstalls it.
### b) `Missing esp-mqtt submodule` / CMake `git_submodule_check` errors
The managed ESP-IDF checkout under `.embuild/espressif/esp-idf/<version>/` needs its git submodules initialized — several ESP-IDF components (mqtt, lwip, mbedtls, wifi/bt libs, etc.) are submodules, and IDF's build requires them present even if your project doesn't use those components.
```bash
cd .embuild/espressif/esp-idf/<version>
git submodule update --init --recursive
cd -
cargo build --release
```
This is a one-time ~500MB1GB download. If it's still broken afterward (partial/shallow clone issues), delete and let `embuild` re-clone fresh:
```bash
rm -rf .embuild/espressif/esp-idf/<version>
cargo build --release
```
### c) Building for host instead of the chip (`Unsupported target 'x86_64-unknown-linux-gnu'`)
`.cargo/config.toml` must set:
```toml
[build]
target = "xtensa-esp32s3-espidf"
```
`esp-idf-template` generates this correctly — if you hit this, something overwrote or is missing that file, or `espup`'s toolchain isn't active in the current shell (`. $HOME/export-esp.sh`).
### d) SPI DMA: `check_trans_valid: txdata transfer > host maximum` / w5500 read-write failures
The default `SpiDriverConfig` has DMA disabled, which caps transfer size below what the W5500 ethernet driver needs to move full frames. Symptom: link never comes up, `wait_netif_up()` hangs, log fills with `w5500_spi_write failed` / `w5500_spi_read failed`. Fix — enable DMA explicitly when constructing the `SpiDriver`:
```rust
use esp_idf_svc::hal::spi::{config::DriverConfig, Dma, SpiDriver};
let spi_driver = SpiDriver::new(
peripherals.spi2,
pins.gpio13, // SCLK
pins.gpio11, // MOSI
Some(pins.gpio12), // MISO
&DriverConfig {
dma: Dma::Auto(4096),
..Default::default()
},
)?;
```
### e) `esp-idf-svc` API drift across versions
The `EthDriver::new_spi` signature has changed across `esp-idf-svc` releases — older versions took raw MOSI/MISO/SCLK pins directly; 0.51+ takes a pre-built `SpiDriver` plus INT/CS/RST only (9 args total: `spi, int, cs, rst, chipset, baudrate, mac_addr, phy_addr, sysloop`). If code from an older tutorial/example doesn't compile, check the exact signature for your pinned version:
```bash
cargo doc --open -p esp-idf-svc
# or browse https://docs.rs/esp-idf-svc/<your-version>/esp_idf_svc/eth/
```
Trust the compiler's error over memory or old examples — it names the exact expected type/arg count.
## 4. sdkconfig.defaults
```
CONFIG_ETH_SPI_ETHERNET_W5500=y
CONFIG_ESP_MAIN_TASK_STACK_SIZE=8000
CONFIG_HTTPD_MAX_REQ_HDR_LEN=1024
```
Without the first line, the W5500 driver component isn't built into ESP-IDF at all — you'll get a runtime or link failure referencing missing eth symbols.
## 5. Cargo.toml essentials
```toml
[dependencies]
esp-idf-svc = { version = "0.51", features = ["std"] }
anyhow = "1"
log = "0.4"
```
## 6. Build / flash / monitor
```bash
cargo build --release
espflash flash --monitor target/xtensa-esp32s3-espidf/release/<binary-name>
```
Watch the serial log for `Got IP: ...` — that confirms both SPI-to-W5500 link and DHCP succeeded. No `Got IP` line + streaming `w5500.mac` errors = revisit DMA config or pin mapping (item d/a above).
## Summary: what each fix actually solved
|Problem|Root cause|Fix|
|---|---|---|
|Config menu had no ethernet option|Wrong scaffolding tool (`esp-generate` = no_std/esp-hal)|Use `esp-idf-template` (std) instead|
|Build targeted host, not chip|Missing/wrong `.cargo/config.toml` target|Ensure `target = "xtensa-esp32s3-espidf"`|
|`esp-clang` failed to load|Host libxml2 soname too new|Symlink `.so.16``.so.2`|
|CMake submodule errors|Managed ESP-IDF git checkout incomplete|`git submodule update --init --recursive`|
|`EthDriver::new_spi` type errors|API changed across esp-idf-svc versions|Match compiler-reported signature exactly, don't trust memorized old examples|
|W5500 never links / SPI transfer errors|DMA disabled by default on SPI bus|`Dma::Auto(4096)` in `DriverConfig`|