diff --git a/vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/dbn_ble_srv.c b/vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/dbn_ble_srv.c
index 454f542..54fe98a 100644
--- a/vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/dbn_ble_srv.c
+++ b/vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/dbn_ble_srv.c
@@ -11,6 +11,7 @@
 #include <string.h>
 #include "net_srv.h"
 #include "offlog.h"
+extern uint16_t peripheral_get_mtu(void);
 
 uint8_t g_flag_notify_temp = 0;             //��ʱ֪ͨnotify flag, 0 disable, 1 enable
 
@@ -181,6 +182,24 @@ static uint8_t set_net_info_to_ready(uint8_t * dat_dst)
     return i;
 }
 
+/* =============================================================
+ * ble_notify_chunk_max: max dat bytes per notify packet
+ *   follow negotiated MTU to avoid 'Too large noti' drop:
+ *   whole pkt = 4B header(magic/header/len/cmd) + dat + 2B ckb
+ *   must satisfy whole pkt <= peripheralMTU - 3 (ATT opcode+handle)
+ *   and whole pkt <= MAX_BLE_Notify_Buf_LEN (local buf, no overflow)
+ *   MTU=23 -> 14, MTU=96 -> 87, MTU>=103 -> 94
+ * =============================================================
+static uint16_t ble_notify_chunk_max(void)
+{
+    uint16_t _mtu = peripheral_get_mtu();
+    if (_mtu < 23) _mtu = ATT_MTU_SIZE;   /* fallback before negotiation */
+    uint16_t _limit = _mtu - 9;            /* pkt limit - header4 - ckb2 */
+    if (_limit > (MAX_BLE_Notify_Buf_LEN - 6))
+        _limit = MAX_BLE_Notify_Buf_LEN - 6;
+    return _limit;
+}
+
 void set_response_iot_net(Buf_DBN_BLE *response_dst)
 {   // config iot_net  
     uint8_t ret = 0;
@@ -205,10 +224,13 @@ void set_response_iot_net(Buf_DBN_BLE *response_dst)
     memcpy(&(response_dst->dat[i]), iot_net_info.password, strlen(iot_net_info.password));
     i += strlen(iot_net_info.password);    
     response_dst->dat_len = i;
-    response_dst->pkg_amount = i / MAX_BLE_DAT_RESPONSE_LEN;
-    if((i % MAX_BLE_DAT_RESPONSE_LEN) > 0)
     {
-        response_dst->pkg_amount += 1;
+        uint16_t _chunk = ble_notify_chunk_max();
+        response_dst->pkg_amount = i / _chunk;
+        if((i % _chunk) > 0)
+        {
+            response_dst->pkg_amount += 1;
+        }
     }
     response_dst->pkg_seq = 0;
     
@@ -232,10 +254,13 @@ void set_response_iot_topic(Buf_DBN_BLE *response_dst)
     memcpy(&(response_dst->dat[i]), g_iot_topic.topic_sub, strlen(g_iot_topic.topic_sub));
     i += strlen(g_iot_topic.topic_sub);
     response_dst->dat_len = i;
-    response_dst->pkg_amount = i / MAX_BLE_DAT_RESPONSE_LEN;
-    if((i % MAX_BLE_DAT_RESPONSE_LEN) > 0)
     {
-        response_dst->pkg_amount += 1;
+        uint16_t _chunk = ble_notify_chunk_max();
+        response_dst->pkg_amount = i / _chunk;
+        if((i % _chunk) > 0)
+        {
+            response_dst->pkg_amount += 1;
+        }
     }
     response_dst->pkg_seq = 0;
     response_dst->flag = 1;
@@ -250,8 +275,9 @@ uint8_t set_response_buf(Buf_DBN_BLE *response_dst, uint8_t magic, uint8_t cmd,
     response_dst->magic = magic;
     response_dst->cmd = cmd;
 
-    uint8_t _amount = dat_len / MAX_BLE_DAT_RESPONSE_LEN;
-    if((dat_len % MAX_BLE_DAT_RESPONSE_LEN) > 0)
+    uint16_t _chunk = ble_notify_chunk_max();
+    uint8_t _amount = dat_len / _chunk;
+    if((dat_len % _chunk) > 0)
     {
         _amount++;
     }
@@ -369,9 +395,12 @@ uint8_t set_response_to_notify(Buf_DBN_BLE *response_ori, BLE_Notify_Buf * notif
         uint8_t _pkg_amount = response_ori->pkg_amount;
         uint8_t _pkg_seq = response_ori->pkg_seq;
         uint8_t _remain_len = response_ori->dat_len - response_ori->dat_offset;
-        if(_remain_len > MAX_BLE_DAT_RESPONSE_LEN)
         {
-            _remain_len = MAX_BLE_DAT_RESPONSE_LEN;
+            uint16_t _chunk = ble_notify_chunk_max();
+            if(_remain_len > _chunk)
+            {
+                _remain_len = (uint8_t)_chunk;
+            }
         }
         _pkg_seq += 1;
         notify_dst->buf[1] = (_pkg_amount << 4)|(_pkg_seq);
diff --git a/vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/peripheral.c b/vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/peripheral.c
index 2961812..e3e8c9f 100644
--- a/vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/peripheral.c
+++ b/vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/peripheral.c
@@ -147,6 +147,11 @@ static uint8_t attDeviceName[GAP_DEVICE_NAME_LEN] = "DLD960GA"; // "Simple Perip
 static peripheralConnItem_t peripheralConnList;
 
 static uint16_t peripheralMTU = ATT_MTU_SIZE;
+/* getter for dbn_ble_srv.c: dynamic notify chunk by negotiated MTU */
+uint16_t peripheral_get_mtu(void)
+{
+    return peripheralMTU;
+}
 /*********************************************************************
  * LOCAL FUNCTIONS
  */
@@ -703,7 +708,7 @@ static void peripheralChar4Notify(uint8_t *pValue, uint16_t len)
     attHandleValueNoti_t noti;
     if(len > (peripheralMTU - 3))
     {
-        PRINT("Too large noti\n");
+        PRINT("Too large noti, len:%d, peripheralMTU:%d\n", len, peripheralMTU);
         return;
     }
     noti.len = len;
diff --git a/vd960DBN/docs/devlog.md b/vd960DBN/docs/devlog.md
index 8db6aac..11a8054 100644
--- a/vd960DBN/docs/devlog.md
+++ b/vd960DBN/docs/devlog.md
@@ -6,6 +6,68 @@
 
 ---
 
+## 2026-08-12 — BLE 分包粒度动态化修复（Too large noti 丢包）
+
+### 背景
+
+`CMD_DBN_OFFLOG_QUERY` 拉取 4 条日志时响应 dat=130B，`set_response_buf` 按 **写死的 `MAX_BLE_DAT_RESPONSE_LEN=96`** 分包：第一包 = 帧头4 + dat96 + ckb2 = **102B**。而小程序把 MTU 协商到 96 后，ATT 通知 payload 上限 = 96-3 = **93B**，`peripheralChar4Notify` 判定 `102 > 93` → **"Too large noti" 直接 return，第一包永久丢失**，小程序重组永远不完整（只收到第二包 34B）。
+
+现场日志证据：
+
+```
+BLE: offlog_query start_seq=1 req=4 fetched=4
+Too large noti, len:102, peripheralMTU:96
+```
+
+### 根因链
+
+| # | 环节 | 问题 |
+|---|------|------|
+| 1 | `BLE_BUFF_MAX_LEN=100` (config.h) | `MAX_BLE_DAT_RESPONSE_LEN = 100-4 = 96` 分包块大小**写死** |
+| 2 | 分包粒度不随协商 MTU 变化 | MTU 协商到 96 后，每包 96B dat 必然超 93B 上限 |
+| 3 | `BLE_Notify_Buf.buf[100]` | `set_response_to_notify` 写 102B → **越界 2B**（UB，可能踩坏相邻 `g_flag_notify_temp`/`g_buf_ble_response`） |
+| 4 | `peripheralChar4Notify` 超限 return | 丢包无重传，小程序重组永久不完整 |
+
+> 2026-08-10 日志中"响应超 96B 自动分包（既有机制）"的假设不成立：分包机制存在但**粒度没跟随协商 MTU**。
+
+### 修复：`ble_notify_chunk_max()` 动态分包
+
+```c
+/* 整包 = 帧头4(magic/header/len/cmd) + dat + ckb2
+   须满足 整包 <= peripheralMTU - 3 (ATT opcode+handle)
+   且 整包 <= MAX_BLE_Notify_Buf_LEN (本地缓冲防越界)
+   MTU=23 -> 14, MTU=96 -> 87, MTU>=103 -> 94 */
+static uint16_t ble_notify_chunk_max(void)
+{
+    uint16_t _mtu = peripheral_get_mtu();
+    if (_mtu < 23) _mtu = ATT_MTU_SIZE;   /* 未协商兜底 */
+    uint16_t _limit = _mtu - 9;            /* 整包上限-帧头4-ckb2 */
+    if (_limit > (MAX_BLE_Notify_Buf_LEN - 6))
+        _limit = MAX_BLE_Notify_Buf_LEN - 6;
+    return _limit;
+}
+```
+
+改动文件（GBK+CRLF，全部 Python 二进制替换）：
+
+| 文件 | 改动 |
+|------|------|
+| `peripheral.c` | 新增 `peripheral_get_mtu()` getter（peripheralMTU 是 static） |
+| `dbn_ble_srv.c` | 新增 `ble_notify_chunk_max()`；`set_response_buf` / `set_response_to_notify` / `set_response_iot_net` / `set_response_iot_topic` 四处 `MAX_BLE_DAT_RESPONSE_LEN` 全部改用动态 chunk（组包包数与实际切包必须同一粒度，否则 pkg_amount 错乱） |
+
+### 验证
+
+- 隔离 C 测试（真实函数体 + mock `peripheral_get_mtu`）：MTU=23/96/185/517 四组，每组验证 chunk 上限、单包 ≤ MTU-3、单包 ≤ 100B 缓冲、帧结构一致、seq 递增、**重组 130B 完整且逐字节一致**，全部 PASS
+- MTU=96 时：2 包（93B + 49B）✓；MTU=185 时：2 包（100B + 42B）✓；MTU=23 未协商时降级 10 包（每包 20B，pkg_amount=10 ≤ header 高4位上限15）
+- 顺带消除 `g_notify_buftemp.buf[100]` 越界 2B 隐患
+- 待板级验证：MRS 真编译 + 真机小程序 QUERY 拉 4 条日志（本地无 RISC-V 工具链）
+
+### 小程序端（可选优化，非必须）
+
+- Android 可在连接后 `wx.setBLEMTU({mtu: 185})`，分包粒度升到 94B/包，减少包数；iOS 系统自动协商，固件已自适应，不调也能正常拉取
+
+---
+
 ## 2026-08-10 — BLE 读取脱机日志接口 (OFFLOG_STAT/QUERY/CLEAR)
 
 ### 背景