From f77e4ae39a7a14be49bd6880c94933812883a77c Mon Sep 17 00:00:00 2001
From: Matt <bread@mailed.me.uk>
Date: Fri, 12 Dec 2025 23:14:49 +0000
Subject: [PATCH] Switch to binary websocket messages

---
 main/index.js |  8 ++++----
 main/main.c   | 37 +++++++++++--------------------------
 2 files changed, 15 insertions(+), 30 deletions(-)

diff --git a/main/index.js b/main/index.js
index 63a5141..41a5014 100644
--- a/main/index.js
+++ b/main/index.js
@@ -177,7 +177,7 @@ function connect() {
   // const wsUrl = 'ws://localhost:8080/signal';
 
   ws = new WebSocket(wsUrl);
-
+  ws.binaryType = 'arraybuffer';
   ws.onopen = () => {
     statusEl.textContent = 'Connected via WebSocket';
     statusEl.style.color = '#4ade80';
@@ -190,9 +190,9 @@ function connect() {
 
   ws.onmessage = (event) => {
     try {
-      const msg = JSON.parse(event.data);
-      if (msg.data && Array.isArray(msg.data)) {
-        processData(msg.data);
+      const arr = new Uint16Array(event.data);
+      if (arr?.length) {
+        processData(arr);
         draw();
       }
     } catch (e) {
diff --git a/main/main.c b/main/main.c
index a7e7bc5..66d6e0d 100644
--- a/main/main.c
+++ b/main/main.c
@@ -482,37 +482,22 @@ static void ws_sender_task(void *arg) {
         s_ringbuf_handle, &item_size, pdMS_TO_TICKS(10));
 
     if (data != NULL) {
-      int num_samples = item_size / sizeof(uint16_t);
       if (s_ws_client_fd != -1) {
-        // Create JSON object
-        cJSON *root = cJSON_CreateObject();
-        cJSON *data_array = cJSON_CreateArray();
-        for (int i = 0; i < num_samples; i++) {
-          cJSON_AddItemToArray(data_array, cJSON_CreateNumber(data[i]));
-        }
-        cJSON_AddItemToObject(root, "data", data_array);
+        // Create WebSocket frame for binary data
+        httpd_ws_frame_t ws_frame = {
+            .final = true,
+            .fragmented = false,
+            .type = HTTPD_WS_TYPE_BINARY,
+            .payload = (uint8_t *)data,
+            .len = item_size
+        };
 
-        // Serialize JSON to string
-        char *json_str = cJSON_PrintUnformatted(root);
-        if (json_str) {
-          httpd_ws_frame_t ws_frame = {
-              .final = true,
-              .fragmented = false,
-              .type = HTTPD_WS_TYPE_TEXT,
-              .payload = (uint8_t *)json_str,
-              .len = strlen(json_str)};
-
-          // Send JSON frame
-          esp_err_t ret = httpd_ws_send_frame_async(s_server, s_ws_client_fd, &ws_frame);
-          if (ret != ESP_OK) {
+        // Send binary frame
+        esp_err_t ret = httpd_ws_send_frame_async(s_server, s_ws_client_fd, &ws_frame);
+        if (ret != ESP_OK) {
             ESP_LOGW(TAG, "WS Send failed, invalidating FD");
             s_ws_client_fd = -1;
-          }
-
-          free(json_str);
         }
-
-        cJSON_Delete(root);
       }
       vRingbufferReturnItem(s_ringbuf_handle, (void *)data);
     } else {