diff --git a/esp/rust/03_aht20/.cargo/config.toml b/esp/rust/04_no-std-aht20/.cargo/config.toml
similarity index 100%
rename from esp/rust/03_aht20/.cargo/config.toml
rename to esp/rust/04_no-std-aht20/.cargo/config.toml
diff --git a/esp/rust/03_aht20/.github/workflows/rust_ci.yml b/esp/rust/04_no-std-aht20/.github/workflows/rust_ci.yml
similarity index 100%
rename from esp/rust/03_aht20/.github/workflows/rust_ci.yml
rename to esp/rust/04_no-std-aht20/.github/workflows/rust_ci.yml
diff --git a/esp/rust/03_aht20/.gitignore b/esp/rust/04_no-std-aht20/.gitignore
similarity index 100%
rename from esp/rust/03_aht20/.gitignore
rename to esp/rust/04_no-std-aht20/.gitignore
diff --git a/esp/rust/03_aht20/Cargo.toml b/esp/rust/04_no-std-aht20/Cargo.toml
similarity index 100%
rename from esp/rust/03_aht20/Cargo.toml
rename to esp/rust/04_no-std-aht20/Cargo.toml
diff --git a/esp/rust/03_aht20/Data-Sheet-AHT20-Humidity-and-Temperature-Sensor-ASAIR-V1.0.03.pdf b/esp/rust/04_no-std-aht20/Data-Sheet-AHT20-Humidity-and-Temperature-Sensor-ASAIR-V1.0.03.pdf
similarity index 100%
rename from esp/rust/03_aht20/Data-Sheet-AHT20-Humidity-and-Temperature-Sensor-ASAIR-V1.0.03.pdf
rename to esp/rust/04_no-std-aht20/Data-Sheet-AHT20-Humidity-and-Temperature-Sensor-ASAIR-V1.0.03.pdf
diff --git a/esp/rust/03_aht20/README.md b/esp/rust/04_no-std-aht20/README.md
similarity index 100%
rename from esp/rust/03_aht20/README.md
rename to esp/rust/04_no-std-aht20/README.md
diff --git a/esp/rust/03_aht20/build.rs b/esp/rust/04_no-std-aht20/build.rs
similarity index 100%
rename from esp/rust/03_aht20/build.rs
rename to esp/rust/04_no-std-aht20/build.rs
diff --git a/esp/rust/03_aht20/rust-toolchain.toml b/esp/rust/04_no-std-aht20/rust-toolchain.toml
similarity index 100%
rename from esp/rust/03_aht20/rust-toolchain.toml
rename to esp/rust/04_no-std-aht20/rust-toolchain.toml
diff --git a/esp/rust/03_aht20/sdkconfig.defaults b/esp/rust/04_no-std-aht20/sdkconfig.defaults
similarity index 100%
rename from esp/rust/03_aht20/sdkconfig.defaults
rename to esp/rust/04_no-std-aht20/sdkconfig.defaults
diff --git a/esp/rust/03_aht20/src/main.rs b/esp/rust/04_no-std-aht20/src/main.rs
similarity index 100%
rename from esp/rust/03_aht20/src/main.rs
rename to esp/rust/04_no-std-aht20/src/main.rs
diff --git a/esp/rust/README.md b/esp/rust/README.md
index b51424b..f9b4d2c 100644
--- a/esp/rust/README.md
+++ b/esp/rust/README.md
@@ -5,6 +5,7 @@ shaunrd0/klips/esp/rust
 ├── 01_esp-idf-std     # Template project for using ESP-IDF with std enabled.
 ├── 02_esp-gen-no-std  # Template ESP32 project using no std.
 ├── 03_no-std-lcd      # Drawing to LCD using ESP32 no std.
+├── 04_no-std-aht20    # Reading temperature and humidity from a AHT20 sensor using ESP32 no std.
 └── README.md
 ```