starting with commands

hello_usb.cpp

@@ -371,6 +371,29 @@ static inline bool find_key_in_report(hid_keyboard_report_t const *report, uint8
     return false;
 }
 
+static bool process_command(const char* input) {
+    if (input[0] != '/') return false;
+
+    if (strcmp(input, "/refresh") == 0) {
+        printf("Command: /refresh\n");
+        g_force_full_refresh = true;
+        send_display_update("", false);
+        return true;
+    } else if (strcmp(input, "/clear") == 0) {
+        printf("Command: /clear\n");
+        g_entry_list.count = 0;
+        memset(g_entry_list.entries, 0, sizeof(g_entry_list.entries));
+        g_force_full_refresh = true;
+        send_display_update("", false);
+        return true;
+    } else if (strcmp(input, "/wifisetup") == 0) {
+        printf("Command: /wifisetup (Not implemented)\n");
+        return true;
+    }
+
+    return false;
+}
+
 static void process_kbd_report(hid_keyboard_report_t const *report) {
     static hid_keyboard_report_t prev_report = { 0, 0, {0} };
 
@@ -403,21 +426,32 @@ static void process_kbd_report(hid_keyboard_report_t const *report) {
                     } else if (is_enter) {
                         printf("\n");
                         
-                        // Update e-Paper (commit line)
+                        if (process_command(g_input_buffer)) {
-                        send_display_update(g_input_buffer, true);
+                            // Command handled, clear buffer but don't commit line
-                        
+                            g_buffer_index = 0;
-                        // Save to last echo
+                            g_input_buffer[0] = '\0';
-                        strncpy(g_last_echo, g_input_buffer, sizeof(g_last_echo) - 1);
+                            
-                        g_last_echo[sizeof(g_last_echo) - 1] = '\0';
+                            if (g_display_manager) {
-                        
+                                g_display_manager->set_last_echo("Command Executed");
-                        // Clear buffer
+                                g_display_manager->refresh("", "Command Executed");
-                        g_buffer_index = 0;
+                            }
-                        g_input_buffer[0] = '\0';
+                        } else {
-                        
+                            // Update e-Paper (commit line)
-                        // Update OLED
+                            send_display_update(g_input_buffer, true);
-                        if (g_display_manager) {
+                            
-                            g_display_manager->set_last_echo(g_last_echo);
+                            // Save to last echo
-                            g_display_manager->refresh("", g_last_echo);
+                            strncpy(g_last_echo, g_input_buffer, sizeof(g_last_echo) - 1);
+                            g_last_echo[sizeof(g_last_echo) - 1] = '\0';
+                            
+                            // Clear buffer
+                            g_buffer_index = 0;
+                            g_input_buffer[0] = '\0';
+                            
+                            // Update OLED
+                            if (g_display_manager) {
+                                g_display_manager->set_last_echo(g_last_echo);
+                                g_display_manager->refresh("", g_last_echo);
+                            }
                         }
                     } else if (is_printable) {
                         printf("%c", ch);
@@ -443,12 +477,25 @@ static void process_kbd_report(hid_keyboard_report_t const *report) {
 // TinyUSB Callbacks
 //--------------------------------------------------------------------+
 
+static bool g_keyboard_mounted = false;
+
+// Invoked when device is suspended
+void tuh_device_suspend_cb(uint8_t dev_addr) {
+    printf("Device address = %d suspended\r\n", dev_addr);
+}
+
+// Invoked when device is resumed
+void tuh_device_resume_cb(uint8_t dev_addr) {
+    printf("Device address = %d resumed\r\n", dev_addr);
+}
+
 void tuh_hid_mount_cb(uint8_t dev_addr, uint8_t instance, uint8_t const* desc_report, uint16_t desc_len) {
     printf("HID device address = %d, instance = %d is mounted\r\n", dev_addr, instance);
 
     uint8_t const itf_protocol = tuh_hid_interface_protocol(dev_addr, instance);
     if (itf_protocol == HID_ITF_PROTOCOL_KEYBOARD) {
         printf("Keyboard mounted\r\n");
+        g_keyboard_mounted = true;
         if (g_display_manager) {
             g_display_manager->refresh("Keyboard Connected", nullptr);
         }
@@ -460,8 +507,14 @@ void tuh_hid_mount_cb(uint8_t dev_addr, uint8_t instance, uint8_t const* desc_re
 
 void tuh_hid_umount_cb(uint8_t dev_addr, uint8_t instance) {
     printf("HID device address = %d, instance = %d is unmounted\r\n", dev_addr, instance);
+    g_keyboard_mounted = false;
+    
+    // Reset input buffer
+    g_buffer_index = 0;
+    g_input_buffer[0] = '\0';
+
     if (g_display_manager) {
-        g_display_manager->refresh("Keyboard Disconnected", nullptr);
+        g_display_manager->refresh("Waiting for Keyboard", nullptr);
     }
 }
 
@@ -503,7 +556,7 @@ int main() {
         
         uint32_t now = to_ms_since_boot(get_absolute_time());
         if (now - last_print > 5000) {
-            printf("Heartbeat: %u\n", now);
+            printf("Heartbeat: %u, Mounted: %d\n", now, g_keyboard_mounted);
             last_print = now;
         }
     }

suspend_fix_notes.md

@@ -0,0 +1,42 @@
+# TinyUSB Host Keyboard Suspend/Freeze Issues on RP2040
+
+## Common Issues
+1. **Device Auto-Suspend:** Some keyboards automatically enter a low-power suspend mode if they don't detect activity or if the host stops sending Start-Of-Frame (SOF) packets.
+2. **Host Controller Freeze:** The RP2040 USB host controller can sometimes get into a state where it stops processing events, especially if there are signal integrity issues or if the `tuh_task()` is blocked for too long.
+3. **Missing Keep-Alive:** If the host doesn't send SOFs, the device will suspend. The RP2040 host should send SOFs automatically when configured as host.
+
+## `tuh_task` Usage
+- **Requirement:** `tuh_task()` must be called continuously and frequently in the main loop.
+- **Blocking:** It should not be blocked by long delays (like `sleep_ms` or blocking display updates) in the same thread.
+- **Current Code:** Your `hello_usb.cpp` calls `tuh_task()` in a tight loop, which is correct. The display updates are offloaded to Core 1, and the FIFO push is non-blocking (checked with `multicore_fifo_wready`), so Core 0 should remain responsive.
+
+## Potential Fixes & Debugging
+
+### 1. Handle Suspend/Resume Callbacks
+TinyUSB provides callbacks to notify the application when a device suspends or resumes. Implementing these can help determine if the device is actually suspending.
+
+Add these to your `hello_usb.cpp`:
+
+```cpp
+// Invoked when device is suspended
+void tuh_device_suspend_cb(uint8_t dev_addr) {
+    printf("Device address = %d suspended\r\n", dev_addr);
+}
+
+// Invoked when device is resumed
+void tuh_device_resume_cb(uint8_t dev_addr) {
+    printf("Device address = %d resumed\r\n", dev_addr);
+}
+```
+
+### 2. Force Resume
+If the device suspends and doesn't wake up, you might need to force a resume from the host side, although usually the device initiates resume (remote wakeup) or the host keeps it awake.
+
+### 3. Check Power
+Ensure the keyboard is receiving sufficient power. Some mechanical keyboards with LEDs draw significant current, potentially causing voltage drops that reset the USB connection or cause a freeze.
+
+### 4. Disable Suspend (Device Side)
+Some devices have internal settings to disable sleep, but this is device-specific.
+
+### 5. SDK/TinyUSB Version
+Ensure you are using a recent version of the Pico SDK and TinyUSB, as there have been fixes for RP2040 host mode stability.