diff --git a/CMakeLists.txt b/CMakeLists.txt
index dc142c53..8322b7a6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,6 +32,8 @@ include_directories(
   ${CMAKE_CURRENT_LIST_DIR}
 )
 
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Werror")
+
 add_subdirectory(common)
 add_subdirectory(drivers)
 add_subdirectory(libraries)
diff --git a/examples/breakout_encoder/demo.cpp b/examples/breakout_encoder/demo.cpp
index e07c44da..aeb627d7 100644
--- a/examples/breakout_encoder/demo.cpp
+++ b/examples/breakout_encoder/demo.cpp
@@ -36,7 +36,7 @@ void from_hsv(float h, float s, float v, uint8_t &r, uint8_t &g, uint8_t &b) {
 void count_changed(int16_t count) {
   printf("Count: %d\n", count);
   float h = (count % STEPS_PER_REV) / (float)STEPS_PER_REV;
-  uint8_t r, g, b;
+  uint8_t r = 0, g = 0, b = 0;
   from_hsv(h, 1.0f, 1.0f, r, g, b);
   enc.set_led(r, g, b);
 }
diff --git a/examples/breakout_potentiometer/demo.cpp b/examples/breakout_potentiometer/demo.cpp
index 8dfebac8..8de69c65 100644
--- a/examples/breakout_potentiometer/demo.cpp
+++ b/examples/breakout_potentiometer/demo.cpp
@@ -37,7 +37,6 @@ int main() {
 
   stdio_init_all();
 
-  int16_t count = 0;
   if(pot.init()) {
     printf("Potentiometer found...\n");
 
@@ -50,7 +49,7 @@ int main() {
       float percent = pot.read();
 
       printf("Percent: %d\n", (int)(percent * 100));
-      uint8_t r, g, b;
+      uint8_t r = 0, g = 0, b = 0;
       from_hsv(percent, 1.0f, 1.0f, r, g, b);
       pot.set_led(r, g, b);
 
diff --git a/examples/breakout_roundlcd/demo.cpp b/examples/breakout_roundlcd/demo.cpp
index 103062e6..b4bc995f 100644
--- a/examples/breakout_roundlcd/demo.cpp
+++ b/examples/breakout_roundlcd/demo.cpp
@@ -17,7 +17,7 @@ BreakoutRoundLCD display(buffer, BG_SPI_FRONT);
 constexpr float RADIUS = BreakoutRoundLCD::WIDTH / 2;
 
 Pen from_hsv(float h, float s, float v) {
-  uint8_t r, g, b;
+  uint8_t r = 0, g = 0, b = 0;
 
   float i = floor(h * 6.0f);
   float f = h * 6.0f - i;
diff --git a/examples/breakout_sgp30/demo.cpp b/examples/breakout_sgp30/demo.cpp
index 825417db..c743712e 100644
--- a/examples/breakout_sgp30/demo.cpp
+++ b/examples/breakout_sgp30/demo.cpp
@@ -19,8 +19,7 @@ BreakoutSGP30 sgp30(&i2c);
 int main() {
   uint8_t prd;
   uint16_t eCO2, TVOC;
-  uint16_t raweCO2, rawTVOC;
-  uint16_t baseCO2, baseTVOC;
+  uint16_t rawCO2, rawTVOC;
 
   gpio_init(PICO_DEFAULT_LED_PIN);
   gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
@@ -57,8 +56,8 @@ int main() {
     sleep_ms(1000 - (100 * prd));
     if(prd == 1) {
       sgp30.get_air_quality(&eCO2, &TVOC);
-      sgp30.get_air_quality_raw(&raweCO2, &rawTVOC);
-      printf("%3d: CO2 %d TVOC %d, raw %d %d\n", j, eCO2, TVOC, raweCO2, rawTVOC);
+      sgp30.get_air_quality_raw(&rawCO2, &rawTVOC);
+      printf("%3d: CO2 %d TVOC %d, raw %d %d\n", j, eCO2, TVOC, rawCO2, rawTVOC);
       if(j == 30) {
         printf("Resetting device\n");
         sgp30.soft_reset();
diff --git a/examples/pico_display/demo.cpp b/examples/pico_display/demo.cpp
index a29d9711..24d859ea 100644
--- a/examples/pico_display/demo.cpp
+++ b/examples/pico_display/demo.cpp
@@ -82,11 +82,6 @@ int main() {
   // uint16_t dark_green = pico_display.create_pen(10, 100, 10);
   // uint16_t blue = pico_display.create_pen(0, 0, 255);
 
-  bool a_pressed = false;
-  bool b_pressed = false;
-  bool x_pressed = false;
-  bool y_pressed = false;
-
   struct pt {
     float      x;
     float      y;
diff --git a/examples/pico_explorer/demo.cpp b/examples/pico_explorer/demo.cpp
index ffa89b4c..6e7cbbf7 100644
--- a/examples/pico_explorer/demo.cpp
+++ b/examples/pico_explorer/demo.cpp
@@ -58,11 +58,6 @@ int main() {
   pico_explorer.init();
   msa301.init();
 
-  bool a_pressed = false;
-  bool b_pressed = false;
-  bool x_pressed = false;
-  bool y_pressed = false;
-
   struct pt {
     float      x;
     float      y;
@@ -160,7 +155,7 @@ int main() {
     float yoff = cos(i / 20.0f) * 50.0f;
     yoff += 120 - (68 / 2);
     for(int y = 0; y < 68; y++) {
-      uint16_t *dest = pico_explorer.frame_buffer + (y * 240);
+      // uint16_t *dest = pico_explorer.frame_buffer + (y * 240);
       uint8_t *src = _binary_fox_tga_start + 18 + (y * 81 * 3);
       for(int x = 0; x < 81; x++) {
         uint8_t b = *src++;
diff --git a/examples/pico_pot_explorer/demo.cpp b/examples/pico_pot_explorer/demo.cpp
index 14752a3c..d5eed107 100644
--- a/examples/pico_pot_explorer/demo.cpp
+++ b/examples/pico_pot_explorer/demo.cpp
@@ -44,7 +44,6 @@ int main() {
   pico_explorer.init();
   pico_explorer.update();
 
-  int16_t count = 0;
   if(pot.init()) {
     printf("Potentiometer found...\n");
 
@@ -55,7 +54,7 @@ int main() {
       float percent = pot.read();
 
       printf("Percent: %d\n", (int)(percent * 100));
-      uint8_t r, g, b;
+      uint8_t r = 0, g = 0, b = 0;
       from_hsv(percent, 1.0f, 1.0f, r, g, b);
       pot.set_led(r, g, b);
 
diff --git a/examples/pico_tof_display/demo.cpp b/examples/pico_tof_display/demo.cpp
index 1404f385..cd750d81 100644
--- a/examples/pico_tof_display/demo.cpp
+++ b/examples/pico_tof_display/demo.cpp
@@ -170,7 +170,7 @@ int main() {
   bool dist_held = false;
 
   while(true) {
-    bool a_pressed = ar_button_a.next(i, pico_display.is_pressed(pico_display.A));
+    // bool a_pressed = ar_button_a.next(i, pico_display.is_pressed(pico_display.A));
     bool b_pressed = ar_button_b.next(i, pico_display.is_pressed(pico_display.B));
     bool x_pressed = ar_button_x.next(i, pico_display.is_pressed(pico_display.X));
     bool y_pressed = ar_button_y.next(i, pico_display.is_pressed(pico_display.Y));
diff --git a/examples/pico_unicorn/demo.cpp b/examples/pico_unicorn/demo.cpp
index 51d253e6..53757347 100644
--- a/examples/pico_unicorn/demo.cpp
+++ b/examples/pico_unicorn/demo.cpp
@@ -40,11 +40,6 @@ int main() {
   uint32_t i = 0;
   while(true) {
     i = i + 1;
-    uint8_t j = 0;
-
-
-
-
 
     if(pico_unicorn.is_pressed(pico_unicorn.A)) { a_pressed = true; }
     if(pico_unicorn.is_pressed(pico_unicorn.B)) { b_pressed = true; }
diff --git a/examples/pico_unicorn_plasma/demo.cpp b/examples/pico_unicorn_plasma/demo.cpp
index 9992497d..c45435af 100644
--- a/examples/pico_unicorn_plasma/demo.cpp
+++ b/examples/pico_unicorn_plasma/demo.cpp
@@ -102,8 +102,9 @@ int main() {
   while(true) {
     int           x1, x2, x3, x4, y1, y2, y3, y4, sx1, sx2, sx3, sx4;
     unsigned char x, y;
-    int8_t          value;
-    uint8_t       r, g, b,j,k,l,m;
+    int8_t        value;
+    uint8_t       r = 0, g = 0, b = 0;
+    uint8_t       j, k, l, m;
 
     // Setup a delay to slow the framerate. 
     // Would be better to read from a timer as some math operations take variable time
diff --git a/examples/pico_wireless/demo.cpp b/examples/pico_wireless/demo.cpp
index f220b5ab..c13417c3 100644
--- a/examples/pico_wireless/demo.cpp
+++ b/examples/pico_wireless/demo.cpp
@@ -66,7 +66,7 @@ int main() {
 
     sleep_ms(1000);
 
-    uint8_t r, g, b;
+    uint8_t r = 0, g = 0, b = 0;
     uint8_t a = 0;
     while(!wireless.is_pressed(PicoWireless::A)) {
         from_hsv((float)a/256.0f, 1, 1, r, g, b);
@@ -79,15 +79,15 @@ int main() {
 
     printf("firmware version Nina %s\n", wireless.get_fw_version());
     uint8_t* mac = wireless.get_mac_address();
-    printf("mac address ", wireless.get_mac_address()[0]);
-    for(uint i =0; i < WL_MAC_ADDR_LENGTH; i++) {
+    printf("mac address ");
+    for(uint i = 0; i < WL_MAC_ADDR_LENGTH; i++) {
       printf("%d:", mac[i]);
     }
     printf("\n");
 
     printf("starting connection\n");
 
-    bool connected = wireless.wifi_set_passphrase(NETWORK, PASSWORD);
+    wireless.wifi_set_passphrase(NETWORK, PASSWORD);
 
     printf("waiting to establish connection status\n");
     while(wireless.get_connection_status() != WL_CONNECTED) {
@@ -103,8 +103,8 @@ int main() {
     wireless.get_gateway_ip(gateway);
     printf("gateway address: %d.%d.%d.%d\n", gateway[0], gateway[1], gateway[2], gateway[3]);
 
-    printf("SSID = %s\n", wireless.get_current_ssid());
-    printf("RSSI = %d\n", wireless.get_current_rssi());
+    printf("SSID = %s\n", wireless.get_current_ssid().c_str());
+    printf("RSSI = %ld\n", wireless.get_current_rssi());
     
     uint8_t t = 0;
     while (true) {      
diff --git a/examples/pico_wireless/rgb_http.cpp b/examples/pico_wireless/rgb_http.cpp
index 23454b59..39cf30e0 100644
--- a/examples/pico_wireless/rgb_http.cpp
+++ b/examples/pico_wireless/rgb_http.cpp
@@ -79,7 +79,7 @@ int socket_accept(int8_t server_sock) {
 }
 
 uint8_t start_server(uint16_t http_port) {
-  printf("Starting server...\n", NETWORK);
+  printf("Starting server...\n");
   // Get a socket for our server
   uint8_t server_sock = wireless.get_socket();
   wireless.start_server(http_port, server_sock);
diff --git a/examples/pico_wireless/sdcard_http.cpp b/examples/pico_wireless/sdcard_http.cpp
index 42eece66..8054e8c8 100644
--- a/examples/pico_wireless/sdcard_http.cpp
+++ b/examples/pico_wireless/sdcard_http.cpp
@@ -103,7 +103,7 @@ bool has_suffix(std::string_view path, std::string_view suffix) {
 }
 
 uint8_t start_server(uint16_t http_port) {
-  printf("Starting server...\n", NETWORK);
+  printf("Starting server...\n");
   // Get a socket for our server
   uint8_t server_sock = wireless.get_socket();
   wireless.start_server(http_port, server_sock);
@@ -237,7 +237,7 @@ int main() {
   printf("Listing /\n");
   f_opendir(dir, "/");
   while(f_readdir(dir, &file) == FR_OK && file.fname[0]) {
-      printf("%s %d\n", file.fname, file.fsize);
+      printf("%s %lld\n", file.fname, file.fsize);
   }
   f_closedir(dir);