allow changing status led brightness

CMakeLists.txt

@@ -45,6 +45,7 @@ target_link_libraries(BattMITM_2.0
         pico_stdlib
         hardware_i2c
         pico_i2c_slave
+        hardware_pwm
 )
 
 # Add the standard include files to the build

config.h

@@ -44,3 +44,4 @@
 #define LAPTOP_I2C_BAUD BATT_I2C_BAUD   // use the same baud (for now)
 
 
+#define STATUS_LED_MAX_BRIGHTNESS 10000 // 0-65535

mitm.c

@@ -83,7 +83,7 @@ void mitm_loop() {
     smbus_transfer_t* transfer = static_queue_peek(mitm_transfer_queue);
     if (transfer == NULL) return;
 
-    status_led(1);
+    status_mitm(true);
 
     while (transfer != NULL) {
 
@@ -170,7 +170,7 @@ void mitm_loop() {
         transfer = static_queue_peek(mitm_transfer_queue);
     } 
 
-    status_led(0);
+    status_mitm(false);
 
 }
 

status.c

@@ -24,13 +24,37 @@
 #include "status.h"
 #include "config.h"
 #include "hardware/gpio.h"
+#include "hardware/pwm.h"
+
+
+#define STATUS_ITEMS 1
+#define STATUS_ITEM_MITM_INDEX 0
+
+
+bool status_item_states[STATUS_ITEMS];
+
 
 void init_status() {
-    gpio_init(STATUS_LED_PIN);
-    gpio_set_dir(STATUS_LED_PIN, GPIO_OUT);
+    pwm_config config = pwm_get_default_config();
+
+    gpio_set_function(STATUS_LED_PIN, GPIO_FUNC_PWM);
+    uint slice_num = pwm_gpio_to_slice_num(STATUS_LED_PIN);
+    pwm_init(slice_num, &config, true);
 }
 
-// blinking leds always make things look cooler than they are
-void status_led(int state) {
-    gpio_put(STATUS_LED_PIN, state);
+void status_led_update() {
+    uint16_t brightness = 0;
+    uint16_t brightness_steps = STATUS_LED_MAX_BRIGHTNESS / STATUS_ITEMS;
+
+    for (int i = 0; i < STATUS_ITEMS; i++) {
+        brightness += brightness_steps * status_item_states[i];
+    }
+
+    pwm_set_gpio_level(STATUS_LED_PIN, brightness);
+}
+
+
+void status_mitm(bool activity) {
+    status_item_states[STATUS_ITEM_MITM_INDEX] = activity;
+    status_led_update();
 }

status.h

@@ -21,6 +21,9 @@
     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
     IN THE SOFTWARE.
  */
+#include <stdbool.h>
 
+// blinking leds always make things look cooler than they are
 void init_status();
-void status_led(int state);
+
+void status_mitm(bool activity);