tcp port send stdio

tcp_debug.cpp

@@ -0,0 +1,137 @@
+#include "tcp_debug.h"
+#include "pico/cyw43_arch.h"
+#include "lwip/tcp.h"
+#include "pico/stdio/driver.h"
+#include <string.h>
+#include <stdio.h>
+
+#define TCP_PORT 4242
+#define DEBUG_BUF_SIZE 2048
+
+// Circular buffer for debug output
+static char debug_buf[DEBUG_BUF_SIZE];
+static volatile int write_idx = 0;
+static volatile int read_idx = 0;
+static struct tcp_pcb *server_pcb = NULL;
+static struct tcp_pcb *client_pcb = NULL;
+
+// Helper to write to buffer
+static void buffer_write(const char *data, int len) {
+    for (int i = 0; i < len; i++) {
+        int next_write = (write_idx + 1) % DEBUG_BUF_SIZE;
+        if (next_write != read_idx) { // Only write if not full
+            debug_buf[write_idx] = data[i];
+            write_idx = next_write;
+        }
+    }
+}
+
+// stdio driver callback
+static void tcp_out_chars(const char *buf, int len) {
+    // Handle CRLF conversion manually if needed, or just write raw
+    // The issue is likely that \n is sent without \r, causing "staircase" effect in raw terminals
+    for (int i = 0; i < len; i++) {
+        if (buf[i] == '\n') {
+            char cr = '\r';
+            buffer_write(&cr, 1);
+        }
+        buffer_write(&buf[i], 1);
+    }
+}
+
+static stdio_driver_t tcp_driver = {
+    .out_chars = tcp_out_chars,
+    .out_flush = NULL,
+    .in_chars = NULL,
+#if PICO_STDIO_ENABLE_CRLF_SUPPORT
+    .crlf_enabled = false
+#endif
+};
+
+// TCP callbacks
+static err_t tcp_server_poll(void *arg, struct tcp_pcb *tpcb) {
+    if (tpcb != client_pcb) return ERR_OK;
+
+    // Check if there is data in the ring buffer to send
+    if (write_idx != read_idx) {
+        int len_to_send = 0;
+        char send_buf[256]; // Temporary buffer for one TCP write chunk
+        
+        // Copy from ring buffer to linear buffer
+        while (write_idx != read_idx && len_to_send < sizeof(send_buf)) {
+            send_buf[len_to_send++] = debug_buf[read_idx];
+            read_idx = (read_idx + 1) % DEBUG_BUF_SIZE;
+        }
+
+        if (len_to_send > 0) {
+            err_t err = tcp_write(tpcb, send_buf, len_to_send, TCP_WRITE_FLAG_COPY);
+            if (err == ERR_OK) {
+                tcp_output(tpcb);
+            } else {
+                // If write failed (e.g. buffer full), rewind read_idx (simple retry logic)
+                // Note: This is a simplification. In a real robust system we might drop data or handle partial writes.
+                // For now, we just lose the data if TCP is full to avoid blocking the system.
+            }
+        }
+    }
+    return ERR_OK;
+}
+
+static err_t tcp_server_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err) {
+    if (!p) {
+        tcp_close(tpcb);
+        client_pcb = NULL;
+        printf("TCP debug client disconnected\n");
+        return ERR_OK;
+    }
+    // We don't expect input, just discard it
+    tcp_recved(tpcb, p->tot_len);
+    pbuf_free(p);
+    return ERR_OK;
+}
+
+static err_t tcp_server_accept(void *arg, struct tcp_pcb *newpcb, err_t err) {
+    if (client_pcb) {
+        // Already have a client, reject or close old?
+        // Let's close the old one and accept the new one (last one wins)
+        tcp_abort(client_pcb);
+    }
+    
+    client_pcb = newpcb;
+    tcp_recv(newpcb, tcp_server_recv);
+    tcp_poll(newpcb, tcp_server_poll, 1); // Poll every 500ms (coarse grain) -> actually arg is interval in 500ms steps? 
+    // Wait, poll interval is passed to tcp_poll. 1 means every 500ms.
+    // We might want faster polling for debug output.
+    // But we can't poll faster than the lwIP timer.
+    // However, we can also trigger writes from the main loop if we wanted, but polling is safer for threading.
+    
+    printf("TCP debug client connected\n");
+    return ERR_OK;
+}
+
+bool tcp_debug_init(void) {
+    if (server_pcb) return true;
+
+    // Register stdio driver
+    stdio_set_driver_enabled(&tcp_driver, true);
+
+    cyw43_arch_lwip_begin();
+    server_pcb = tcp_new_ip_type(IPADDR_TYPE_ANY);
+    if (!server_pcb) {
+        cyw43_arch_lwip_end();
+        return false;
+    }
+
+    err_t err = tcp_bind(server_pcb, IP_ANY_TYPE, TCP_PORT);
+    if (err != ERR_OK) {
+        cyw43_arch_lwip_end();
+        return false;
+    }
+
+    server_pcb = tcp_listen(server_pcb);
+    tcp_accept(server_pcb, tcp_server_accept);
+    cyw43_arch_lwip_end();
+
+    printf("TCP debug server listening on port %d\n", TCP_PORT);
+    return true;
+}