diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
new file mode 100644
index 00000000..172b851b
--- /dev/null
+++ b/.devcontainer/Dockerfile
@@ -0,0 +1,30 @@
+FROM debian:bullseye
+ENV DEBIAN_FRONTEND=noninteractive
+ENV LC_ALL=C.UTF-8
+ENV LANG=C.UTF-8
+ARG CONTAINER_USER=esp
+ARG CONTAINER_GROUP=esp
+ARG NIGHTLY_VERSION=nightly-2022-03-10
+RUN apt-get update \
+    && apt-get install -y vim nano git curl gcc ninja-build cmake libudev-dev \
+    python3 python3-pip libusb-1.0-0 libssl-dev pkg-config libtinfo5 clang \
+    && apt-get clean -y && rm -rf /var/lib/apt/lists/* /tmp/library-scripts
+RUN adduser --disabled-password --gecos "" ${CONTAINER_USER}
+USER ${CONTAINER_USER}
+WORKDIR /home/${CONTAINER_USER}
+ENV PATH=${PATH}:$HOME/.cargo/bin
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- \
+    --default-toolchain ${NIGHTLY_VERSION} -y \
+    && $HOME/.cargo/bin/rustup component add rust-src --toolchain ${NIGHTLY_VERSION} \
+    && $HOME/.cargo/bin/rustup target add riscv32i-unknown-none-elf \
+    && $HOME/.cargo/bin/cargo install cargo-generate cargo-espflash espmonitor bindgen ldproxy
+ENV ESP_BOARD=esp32c3
+ENV ESP_IDF_VERSION=release/v4.4
+RUN mkdir -p .espressif/frameworks/ \
+    && git clone --branch ${ESP_IDF_VERSION} -q --depth 1 --shallow-submodules \
+    --recursive https://github.com/espressif/esp-idf.git \
+    .espressif/frameworks/esp-idf-v4.4 \
+    && .espressif/frameworks/esp-idf-v4.4/install.sh ${ESP_BOARD} \
+    && rm -rf .espressif/dist \
+    && rm -rf .espressif/frameworks/esp-idf-v4.4/docs
+CMD "/bin/bash"
\ No newline at end of file
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
new file mode 100755
index 00000000..642c1e0a
--- /dev/null
+++ b/.devcontainer/devcontainer.json
@@ -0,0 +1,34 @@
+{
+  "name": "espressif-training",
+  "build": {
+    "dockerfile": "Dockerfile",
+    "args": {
+      "NIGHTLY_VERSION": "nightly-2022-03-10",
+      "CONTAINER_USER": "esp"
+    }
+  },
+  "settings": {
+    "editor.formatOnPaste": true,
+    "editor.formatOnSave": true,
+    "editor.formatOnSaveMode": "modifications",
+    "editor.formatOnType": true,
+    "lldb.executable": "/usr/bin/lldb",
+    "files.watcherExclude": {
+      "**/target/**": true
+    },
+    "rust-analyzer.checkOnSave.command": "clippy",
+    "[rust]": {
+      "editor.defaultFormatter": "matklad.rust-analyzer"
+    },
+  },
+  "extensions": [
+    "matklad.rust-analyzer",
+    "tamasfe.even-better-toml",
+    "vadimcn.vscode-lldb",
+    "serayuzgur.crates",
+    "mutantdino.resourcemonitor",
+    "yzhang.markdown-all-in-one",
+  ],
+  "workspaceMount": "source=${localWorkspaceFolder},target=/home/esp/workspace,type=bind,consistency=cached",
+  "workspaceFolder": "/home/esp/workspace/"
+}
\ No newline at end of file
diff --git a/advanced/button-interrupt/exercise/Cargo.toml b/advanced/button-interrupt/exercise/Cargo.toml
index 59868c1a..7446982c 100644
--- a/advanced/button-interrupt/exercise/Cargo.toml
+++ b/advanced/button-interrupt/exercise/Cargo.toml
@@ -26,4 +26,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/advanced/button-interrupt/solution/Cargo.toml b/advanced/button-interrupt/solution/Cargo.toml
index e47ba7f9..cc49e0a6 100644
--- a/advanced/button-interrupt/solution/Cargo.toml
+++ b/advanced/button-interrupt/solution/Cargo.toml
@@ -26,4 +26,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/advanced/i2c-driver/solution/Cargo.toml b/advanced/i2c-driver/solution/Cargo.toml
index 682ea66a..67c0085c 100644
--- a/advanced/i2c-driver/solution/Cargo.toml
+++ b/advanced/i2c-driver/solution/Cargo.toml
@@ -28,4 +28,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/advanced/i2c-sensor-reading/solution/Cargo.toml b/advanced/i2c-sensor-reading/solution/Cargo.toml
index 8e5a9982..d2cb259f 100644
--- a/advanced/i2c-sensor-reading/solution/Cargo.toml
+++ b/advanced/i2c-sensor-reading/solution/Cargo.toml
@@ -33,4 +33,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/common/lib/esp32-c3-dkc02-bsc/Cargo.toml b/common/lib/esp32-c3-dkc02-bsc/Cargo.toml
index 74a2a8e7..fb410ab8 100644
--- a/common/lib/esp32-c3-dkc02-bsc/Cargo.toml
+++ b/common/lib/esp32-c3-dkc02-bsc/Cargo.toml
@@ -19,4 +19,4 @@ toml-cfg = "0.1"
 riscv = { version = "0.7", features=["inline-asm"] }
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/common/lib/esp32-c3-dkc02-bsc/src/wifi.rs b/common/lib/esp32-c3-dkc02-bsc/src/wifi.rs
index 741ddbe2..73d7ed14 100644
--- a/common/lib/esp32-c3-dkc02-bsc/src/wifi.rs
+++ b/common/lib/esp32-c3-dkc02-bsc/src/wifi.rs
@@ -4,7 +4,8 @@ use std::sync::Arc;
 
 use anyhow::bail;
 use embedded_svc::wifi::{
-    self, ClientConfiguration, ClientConnectionStatus, ClientIpStatus, ClientStatus, Wifi as _,
+    self, AuthMethod, ClientConfiguration, ClientConnectionStatus, ClientIpStatus, ClientStatus,
+    Wifi as _,
 };
 use esp_idf_svc::{
     netif::EspNetifStack, nvs::EspDefaultNvs, sysloop::EspSysLoopStack, wifi::EspWifi,
@@ -20,11 +21,13 @@ pub struct Wifi {
 }
 
 pub fn wifi(ssid: &str, psk: &str) -> anyhow::Result<Wifi> {
+    let mut auth_method = AuthMethod::WPA2Personal;
     if ssid.len() == 0 {
         anyhow::bail!("missing WiFi name")
     }
     if psk.len() == 0 {
-        anyhow::bail!("missing WiFi password")
+        auth_method = AuthMethod::None;
+        info!("Wifi password is empty");
     }
     let netif_stack = Arc::new(EspNetifStack::new()?);
     let sys_loop_stack = Arc::new(EspSysLoopStack::new()?);
@@ -60,6 +63,7 @@ pub fn wifi(ssid: &str, psk: &str) -> anyhow::Result<Wifi> {
         ssid: ssid.into(),
         password: psk.into(),
         channel,
+        auth_method: auth_method,
         ..Default::default()
     }))?;
 
diff --git a/intro/hardware-check/Cargo.toml b/intro/hardware-check/Cargo.toml
index 0658bb18..41dc2caa 100644
--- a/intro/hardware-check/Cargo.toml
+++ b/intro/hardware-check/Cargo.toml
@@ -28,4 +28,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/intro/http-client/exercise/Cargo.toml b/intro/http-client/exercise/Cargo.toml
index 84572c3e..bf2a4d58 100644
--- a/intro/http-client/exercise/Cargo.toml
+++ b/intro/http-client/exercise/Cargo.toml
@@ -29,4 +29,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/intro/http-client/solution/Cargo.toml b/intro/http-client/solution/Cargo.toml
index 9acd4564..63b124dd 100644
--- a/intro/http-client/solution/Cargo.toml
+++ b/intro/http-client/solution/Cargo.toml
@@ -29,4 +29,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/intro/http-server/exercise/Cargo.toml b/intro/http-server/exercise/Cargo.toml
index b44dad04..7fa4a268 100644
--- a/intro/http-server/exercise/Cargo.toml
+++ b/intro/http-server/exercise/Cargo.toml
@@ -30,4 +30,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/intro/http-server/solution/Cargo.toml b/intro/http-server/solution/Cargo.toml
index b44dad04..7fa4a268 100644
--- a/intro/http-server/solution/Cargo.toml
+++ b/intro/http-server/solution/Cargo.toml
@@ -30,4 +30,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/intro/mqtt/exercise/Cargo.toml b/intro/mqtt/exercise/Cargo.toml
index 861d6cab..56d3828c 100644
--- a/intro/mqtt/exercise/Cargo.toml
+++ b/intro/mqtt/exercise/Cargo.toml
@@ -35,4 +35,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}
diff --git a/intro/mqtt/solution/Cargo.toml b/intro/mqtt/solution/Cargo.toml
index 861d6cab..56d3828c 100644
--- a/intro/mqtt/solution/Cargo.toml
+++ b/intro/mqtt/solution/Cargo.toml
@@ -35,4 +35,4 @@ embuild = "0.28"
 anyhow = "1"
 
 [patch.crates-io]
-riscv = { git = "https://github.com/rust-embedded/riscv", branch = "master"}
+riscv = { git = "https://github.com/rust-embedded/riscv", rev = "396fb9b"}