diff --git a/glue/rust/Cargo.toml b/glue/rust/Cargo.toml
index 83a9add..d115754 100644
--- a/glue/rust/Cargo.toml
+++ b/glue/rust/Cargo.toml
@@ -15,9 +15,10 @@ keywords = ["warduino", "wasm"]
 license = "MPL-2.0"
 
 [dependencies]
-num = "0.4"
-num-traits = "0.2"
-num-derive = "0.3"
+num = { version = "0.4.3", default-features = false }
+num-derive = { version = "0.4.2", default-features = false }
+num-traits = { version = "0.2.19", default-features = false }
+
 
 [[example]]
 name = "blink"
diff --git a/glue/rust/examples/button.rs b/glue/rust/examples/button.rs
index 98c0f2e..084bb2d 100644
--- a/glue/rust/examples/button.rs
+++ b/glue/rust/examples/button.rs
@@ -1,13 +1,21 @@
 // config::BUTTON demo app
-use warduino::{delay, digital_read, digital_write, InterruptMode, pin_mode, PinMode, PinVoltage, sub_interrupt};
+use warduino::{
+    delay, digital_read, digital_write, pin_mode, sub_interrupt, InterruptMode, PinMode, PinVoltage,
+};
 
 mod config;
 
-fn callback(_topic: &str, _payload: &str, _length: u32) {
+fn callback(
+    _topic: *const u8,
+    _topic_length: usize,
+    _payload: *const u8,
+    _payload_length: usize,
+    _length: u32,
+) {
     let voltage = digital_read(config::LED);
     match voltage {
         PinVoltage::HIGH => digital_write(config::LED, PinVoltage::LOW),
-        PinVoltage::LOW => digital_write(config::LED, PinVoltage::HIGH)
+        PinVoltage::LOW => digital_write(config::LED, PinVoltage::HIGH),
     }
 }
 
@@ -22,4 +30,3 @@ pub fn main() {
         delay(1000);
     }
 }
-
diff --git a/glue/rust/examples/config.rs b/glue/rust/examples/config.rs
index bc89a73..20f3ba0 100644
--- a/glue/rust/examples/config.rs
+++ b/glue/rust/examples/config.rs
@@ -4,4 +4,6 @@ pub static SSID: &str = "local-network";
 pub static PASSWORD: &str = "network-password";
 pub static BROKER_URL: &str = "192.168.0.24";
 pub static BROKER_PORT: u32 = 1883;
-pub static CLIENT_ID: &str = "random-mqtt-client-id";
\ No newline at end of file
+pub static CLIENT_ID: &str = "random-mqtt-client-id";
+
+fn main() {}
diff --git a/glue/rust/examples/smartlamp.rs b/glue/rust/examples/smartlamp.rs
index 5825e26..bf6a81e 100644
--- a/glue/rust/examples/smartlamp.rs
+++ b/glue/rust/examples/smartlamp.rs
@@ -1,7 +1,9 @@
 // Simple smart lamp app demo
-use warduino::{delay, digital_read, digital_write, InterruptMode, mqtt_connect, mqtt_connected,
-               mqtt_init, mqtt_loop, mqtt_publish, mqtt_subscribe, pin_mode, PinMode, PinVoltage,
-               print, sleep, sub_interrupt, wifi_connect, wifi_connected, wifi_localip};
+use warduino::{
+    delay, digital_read, digital_write, mqtt_connect, mqtt_connected, mqtt_init, mqtt_loop,
+    mqtt_publish, mqtt_subscribe, pin_mode, print, sleep, sub_interrupt, wifi_connect,
+    wifi_connected, wifi_localip, InterruptMode, PinMode, PinVoltage,
+};
 
 mod config;
 
@@ -12,13 +14,24 @@ fn until(done: fn() -> bool, attempt: fn()) {
     }
 }
 
-fn callback(topic: &str, payload: &str, size: u32) {
+fn callback(
+    topic: *const u8,
+    topic_len: usize,
+    payload: *const u8,
+    payload_length: usize,
+    size: u32,
+) {
+    let topic =
+        unsafe { std::str::from_utf8_unchecked(std::slice::from_raw_parts(topic, topic_len)) };
+    let payload = unsafe {
+        std::str::from_utf8_unchecked(std::slice::from_raw_parts(payload, payload_length))
+    };
     print(&format!("Message [{}] {}\n", topic, payload));
 
     if payload.contains("on") {
-        digital_write(config::LED, PinVoltage::HIGH);  // Turn the LED on
+        digital_write(config::LED, PinVoltage::HIGH); // Turn the LED on
     } else {
-        digital_write(config::LED, PinVoltage::LOW);   // Turn the LED off
+        digital_write(config::LED, PinVoltage::LOW); // Turn the LED off
     }
 }
 
@@ -29,7 +42,13 @@ fn invert(voltage: PinVoltage) -> PinVoltage {
     }
 }
 
-fn toggle_led(_topic: &str, _payload: &str, _size: u32) {
+fn toggle_led(
+    _topic: *const u8,
+    _topic_length: usize,
+    _payload: *const u8,
+    _payload_length: usize,
+    _size: u32,
+) {
     // Get current status of LED
     let status = digital_read(config::LED);
     // Toggle LED
@@ -43,7 +62,9 @@ pub fn main() {
     pin_mode(config::BUTTON, PinMode::INPUT);
 
     // Connect to Wi-Fi
-    until(wifi_connected, || wifi_connect(config::SSID, config::PASSWORD));
+    until(wifi_connected, || {
+        wifi_connect(config::SSID, config::PASSWORD)
+    });
     let message: String = "Connected to wifi network with ip: ".to_owned() + &wifi_localip();
     print(&message);
 
diff --git a/glue/rust/src/lib.rs b/glue/rust/src/lib.rs
index fed51b2..845e9e5 100644
--- a/glue/rust/src/lib.rs
+++ b/glue/rust/src/lib.rs
@@ -34,13 +34,16 @@
 //! ```
 
 #![crate_name = "warduino"]
+#![no_std]
+extern crate alloc;
 
 extern crate num;
 #[macro_use]
 extern crate num_derive;
 
+use alloc::{borrow::ToOwned, string::String};
+use core::mem;
 use linking::*;
-use std::mem;
 
 mod linking;
 
@@ -91,28 +94,46 @@ pub enum PinMode {
 }
 
 /// Returns the number of milliseconds passed since the current program started to run.
-pub fn millis() -> u32 { unsafe { _millis() } }
+pub fn millis() -> u32 {
+    unsafe { _millis() }
+}
 
 /// Pauses the program for the amount of time (in milliseconds).
-pub fn delay(ms: u32) { unsafe { _delay(ms); } }
+pub fn delay(ms: u32) {
+    unsafe {
+        _delay(ms);
+    }
+}
 
 /// Pauses the program for the amount of time (in seconds)
-pub fn sleep(s: u32) { delay(s * 1000); }
+pub fn sleep(s: u32) {
+    delay(s * 1000);
+}
 
 /// Configures the [PinMode] of the specified pin.
-pub fn pin_mode(pin: u32, mode: PinMode) { unsafe { _pinMode(pin, mode as u32) } }
+pub fn pin_mode(pin: u32, mode: PinMode) {
+    unsafe { _pinMode(pin, mode as u32) }
+}
 
 /// Write the voltage to a specified digital pin, either [HIGH](PinVoltage) or [LOW](PinVoltage).
-pub fn digital_write(pin: u32, value: PinVoltage) { unsafe { _digitalWrite(pin, value as u32) } }
+pub fn digital_write(pin: u32, value: PinVoltage) {
+    unsafe { _digitalWrite(pin, value as u32) }
+}
 
 /// Reads the value from a specified digital pin, either [HIGH](PinVoltage) or [LOW](PinVoltage).
-pub fn digital_read(pin: u32) -> PinVoltage { unsafe { num::FromPrimitive::from_u32(_digitalRead(pin)).unwrap() } }
+pub fn digital_read(pin: u32) -> PinVoltage {
+    unsafe { num::FromPrimitive::from_u32(_digitalRead(pin)).unwrap() }
+}
 
 /// Reads the value from the specified analog pin.
-pub fn analog_read(pin: u32) -> i32 { unsafe { _analogRead(pin) } }
+pub fn analog_read(pin: u32) -> i32 {
+    unsafe { _analogRead(pin) }
+}
 
 /// Writes the value to the specified analog pin.
-pub fn analog_write(pin: u32, signal: u32) -> i32 { unsafe { _analogWrite(pin, signal) } }
+pub fn analog_write(pin: u32, signal: u32) -> i32 {
+    unsafe { _analogWrite(pin, signal) }
+}
 
 /// The status of the Wi-Fi connection
 #[derive(FromPrimitive, PartialEq)]
@@ -136,59 +157,91 @@ pub enum WiFiStatus {
 }
 
 /// Connect to Wi-Fi network with SSID and password
-pub fn wifi_connect(ssid: &str, password: &str) { unsafe { _connect(ssid, password) } }
+pub fn wifi_connect(ssid: &str, password: &str) {
+    unsafe { _connect(ssid.as_ptr(), ssid.len(), password.as_ptr(), password.len()) }
+}
 
 /// Returns the status of the Wi-Fi connection of the board
-pub fn wifi_status() -> WiFiStatus { unsafe { num::FromPrimitive::from_i32(_status()).unwrap() } }
+pub fn wifi_status() -> WiFiStatus {
+    unsafe { num::FromPrimitive::from_i32(_status()).unwrap() }
+}
 
 /// Returns whether the board si still connected to Wi-Fi
-pub fn wifi_connected() -> bool { wifi_status() == WiFiStatus::Connected }
+pub fn wifi_connected() -> bool {
+    wifi_status() == WiFiStatus::Connected
+}
 
 /// Returns the local IP address of the board
-pub fn wifi_localip() -> String {
+pub fn with_wifi_localip<T>(then: impl FnOnce(&str) -> T) -> T {
     unsafe {
         let buffer: [u8; 100] = [0; 100];
-        _localip(buffer.as_ptr(), mem::size_of_val(&buffer) / mem::size_of::<u8>());
-        std::str::from_utf8(&buffer).unwrap().to_owned()
+        _localip(
+            buffer.as_ptr(),
+            mem::size_of_val(&buffer) / mem::size_of::<u8>(),
+        );
+        then(core::str::from_utf8(&buffer).unwrap())
     }
 }
 
 const BUFFER_SIZE: usize = 250;
 
 /// Send an HTTP GET request.
-pub fn get(url: &str) -> &str {
-    const BUFFER: &[u8; BUFFER_SIZE] = &[0; BUFFER_SIZE];
-    unsafe { 
-        _get(url.as_ptr(), url.len(), BUFFER.as_ptr(), mem::size_of_val(BUFFER) / mem::size_of::<u8>());
-        std::str::from_utf8_unchecked(BUFFER)
+pub fn with_get<T>(url: &str, then: impl FnOnce(&str) -> T) -> T {
+    let BUFFER: [u8; BUFFER_SIZE] = [0; BUFFER_SIZE];
+    unsafe {
+        _get(
+            url.as_ptr(),
+            url.len(),
+            BUFFER.as_ptr(),
+            mem::size_of_val(&BUFFER) / mem::size_of::<u8>(),
+        );
+        then(core::str::from_utf8_unchecked(&BUFFER))
     }
 }
 
 /// Send an HTTP POST request.
-pub fn post(options: &PostOptions) -> &str {
-    const BUFFER: &[u8; BUFFER_SIZE] = &[0; BUFFER_SIZE];
+pub fn with_post<T>(options: &PostOptions, then: impl FnOnce(&str) -> T) -> T {
+    let BUFFER: [u8; BUFFER_SIZE] = [0; BUFFER_SIZE];
     unsafe {
-        _post(options.uri.as_ptr(), options.uri.len(),
-              options.body.as_ptr(), options.body.len(),
-              options.headers.content_type.as_ptr(), options.headers.content_type.len(),
-              options.headers.authorization.as_ptr(), options.headers.authorization.len(),
-              BUFFER.as_ptr(), mem::size_of_val(BUFFER) / mem::size_of::<u8>());
-        std::str::from_utf8_unchecked(BUFFER)
+        _post(
+            options.uri.as_ptr(),
+            options.uri.len(),
+            options.body.as_ptr(),
+            options.body.len(),
+            options.headers.content_type.as_ptr(),
+            options.headers.content_type.len(),
+            options.headers.authorization.as_ptr(),
+            options.headers.authorization.len(),
+            BUFFER.as_ptr(),
+            mem::size_of_val(&BUFFER) / mem::size_of::<u8>(),
+        );
+        then(core::str::from_utf8_unchecked(&BUFFER))
     }
-
 }
 
 /// Print a string to the serial port.
-pub fn print(text: &str) { unsafe { _print_buffer(text.as_ptr(), text.len()) } }
+pub fn print(text: &str) {
+    unsafe { _print_buffer(text.as_ptr(), text.len()) }
+}
 
 /// Print an integer to the serial port.
-pub fn print_int(integer: i32) { unsafe { _print_int(integer) } }
+pub fn print_int(integer: i32) {
+    unsafe { _print_int(integer) }
+}
 
 /// subscribe a callback function to an interrupt on the given pin
-pub fn sub_interrupt(pin: u32, mode: InterruptMode, f: fn(&str, &str, u32)) { unsafe { _sub_interrupt(pin, f, mode as u32) } }
+pub fn sub_interrupt(
+    pin: u32,
+    mode: InterruptMode,
+    f: fn(*const u8, usize, *const u8, usize, u32),
+) {
+    unsafe { _sub_interrupt(pin, f, mode as u32) }
+}
 
 /// Unsubscribe all callback functions for a given pin
-pub fn unsub_interrupt(pin: u32) { unsafe { _unsub_interrupt(pin) } }
+pub fn unsub_interrupt(pin: u32) {
+    unsafe { _unsub_interrupt(pin) }
+}
 
 /// The status of the MQTT connection
 #[derive(FromPrimitive, PartialEq)]
@@ -216,26 +269,41 @@ pub enum MQTTStatus {
 }
 
 /// Configure a MQTT broker
-pub fn mqtt_init(server: &str, port: u32) { unsafe { _mqtt_init(server.as_ptr(), server.len(), port) } }
+pub fn mqtt_init(server: &str, port: u32) {
+    unsafe { _mqtt_init(server.as_ptr(), server.len(), port) }
+}
 
 /// Connect to the Configured MQTT broker with client_id
-pub fn mqtt_connect(client_id: &str) -> bool { unsafe { _mqtt_connect(client_id.as_ptr(), client_id.len()) != 0 } }
+pub fn mqtt_connect(client_id: &str) -> bool {
+    unsafe { _mqtt_connect(client_id.as_ptr(), client_id.len()) != 0 }
+}
 
 /// Returns whether the board is still connected to the MQTT broker
-pub fn mqtt_connected() -> bool { mqtt_state() == MQTTStatus::Connected }
+pub fn mqtt_connected() -> bool {
+    mqtt_state() == MQTTStatus::Connected
+}
 
 /// Returns the status of the connection to the MQTT broker
-pub fn mqtt_state() -> MQTTStatus { unsafe { num::FromPrimitive::from_i32(_mqtt_state()).unwrap() } }
+pub fn mqtt_state() -> MQTTStatus {
+    unsafe { num::FromPrimitive::from_i32(_mqtt_state()).unwrap() }
+}
 
 /// Publish a message on an MQTT topic
-pub fn mqtt_publish(topic: &str, payload: &str) -> i32 { unsafe { _mqtt_publish(topic.as_ptr(), topic.len(), payload.as_ptr(), payload.len()) } }
+pub fn mqtt_publish(topic: &str, payload: &str) -> i32 {
+    unsafe { _mqtt_publish(topic.as_ptr(), topic.len(), payload.as_ptr(), payload.len()) }
+}
 
 /// Subscribe a callback function to an MQTT topic
-pub fn mqtt_subscribe(topic: &str, f: fn(&str, &str, u32)) -> i32 { unsafe { _mqtt_subscribe(topic.as_ptr(), topic.len(), f) } }
+pub fn mqtt_subscribe(topic: &str, f: fn(*const u8, usize, *const u8, usize, u32)) -> i32 {
+    unsafe { _mqtt_subscribe(topic.as_ptr(), topic.len(), f) }
+}
 
 /// Unsubscribe a callback function from an MQTT topic
-pub fn mqtt_unsubscribe(topic: &str, f: fn(&str, &str, u32)) -> i32 { unsafe { _mqtt_unsubscribe(topic.as_ptr(), topic.len(), f) } }
+pub fn mqtt_unsubscribe(topic: &str, f: fn(*const u8, usize, *const u8, usize, u32)) -> i32 {
+    unsafe { _mqtt_unsubscribe(topic.as_ptr(), topic.len(), f) }
+}
 
 /// Check for messages from the MQTT broker
-pub fn mqtt_poll() -> i32 { unsafe { _mqtt_loop() } }
-
+pub fn mqtt_poll() -> i32 {
+    unsafe { _mqtt_loop() }
+}
diff --git a/glue/rust/src/linking.rs b/glue/rust/src/linking.rs
index 475ab28..07e0520 100644
--- a/glue/rust/src/linking.rs
+++ b/glue/rust/src/linking.rs
@@ -1,5 +1,5 @@
 #[link(wasm_import_module = "env")]
-extern {
+extern "C" {
     // Time
     #[link_name = "millis"]
     pub fn _millis() -> u32;
@@ -28,7 +28,12 @@ extern {
 
     // Wi-Fi
     #[link_name = "wifi_connect"]
-    pub fn _connect(ssid: &str, password: &str);
+    pub fn _connect(
+        ssid: *const u8,
+        ssid_length: usize,
+        password: *const u8,
+        password_length: usize,
+    );
     #[link_name = "wifi_status"]
     pub fn _status() -> i32;
     #[link_name = "wifi_localip"]
@@ -38,16 +43,22 @@ extern {
     #[link_name = "http_get"]
     pub fn _get(url: *const u8, url_len: usize, buffer: *const u8, buffer_size: usize) -> i32;
     #[link_name = "http_post"]
-    pub fn _post(url: *const u8, url_len: usize,
-             body: *const u8, body_len: usize,
-             content_type: *const u8, content_type_len: usize,
-             authorization: *const u8, authorization_len: usize,
-             buffer: *const u8, buffer_size: usize)
-             -> i32;
+    pub fn _post(
+        url: *const u8,
+        url_len: usize,
+        body: *const u8,
+        body_len: usize,
+        content_type: *const u8,
+        content_type_len: usize,
+        authorization: *const u8,
+        authorization_len: usize,
+        buffer: *const u8,
+        buffer_size: usize,
+    ) -> i32;
 
     // Interrupts
     #[link_name = "subscribe_interrupt"]
-    pub fn _sub_interrupt(pin: u32, f: fn(&str, &str, u32), mode: u32);
+    pub fn _sub_interrupt(pin: u32, f: fn(*const u8, usize, *const u8, usize, u32), mode: u32);
     #[link_name = "unsubscribe_interrupt"]
     pub fn _unsub_interrupt(pin: u32);
 
@@ -61,11 +72,24 @@ extern {
     #[link_name = "mqtt_state"]
     pub fn _mqtt_state() -> i32;
     #[link_name = "mqtt_publish"]
-    pub fn _mqtt_publish(topic: *const u8, topic_length: usize, payload: *const u8, payload_length: usize) -> i32;
+    pub fn _mqtt_publish(
+        topic: *const u8,
+        topic_length: usize,
+        payload: *const u8,
+        payload_length: usize,
+    ) -> i32;
     #[link_name = "mqtt_subscribe"]
-    pub fn _mqtt_subscribe(topic: *const u8, topic_length: usize, f: fn(&str, &str, u32)) -> i32;
+    pub fn _mqtt_subscribe(
+        topic: *const u8,
+        topic_length: usize,
+        f: fn(*const u8, usize, *const u8, usize, u32),
+    ) -> i32;
     #[link_name = "mqtt_unsubscribe"]
-    pub fn _mqtt_unsubscribe(topic: *const u8, topic_length: usize, f: fn(&str, &str, u32)) -> i32;
+    pub fn _mqtt_unsubscribe(
+        topic: *const u8,
+        topic_length: usize,
+        f: fn(*const u8, usize, *const u8, usize, u32),
+    ) -> i32;
     #[link_name = "mqtt_loop"]
     pub fn _mqtt_loop() -> i32;
 }