diff --git a/homework3/.eide/eide.json b/homework3/.eide/eide.json
index 8889ee1..cf6ed1b 100644
--- a/homework3/.eide/eide.json
+++ b/homework3/.eide/eide.json
@@ -19,7 +19,8 @@
   "targets": {
     "Debug": {
       "excludeList": [
-        "src/test1.c"
+        "src/test1.c",
+        "src/test2.c"
       ],
       "toolchain": "Keil_C51",
       "compileConfig": {
diff --git a/homework3/src/test3.c b/homework3/src/test3.c
new file mode 100644
index 0000000..7488930
--- /dev/null
+++ b/homework3/src/test3.c
@@ -0,0 +1,33 @@
+// test3.c
+// 左右流水灯
+
+#include "homework3.h"
+
+unsigned char cnt = 0;
+
+void test3()
+{
+    ENLED = 0;
+    ADDR3 = 1;
+    ADDR2 = 1;
+    ADDR1 = 1;
+    ADDR0 = 0;
+
+    while (true) {
+        if(cnt < 8) {
+            P2 = ~(0x01 << cnt);    // 左向流水
+        } else {
+            P2 = ~(0x80 >> (cnt-8)); // 右向流水
+        }
+        Delay(20000);
+        cnt++;
+        if (cnt >= 16) {  // 0-7左移，8-15右移
+            cnt = 0;
+        }
+    }
+}
+
+void main()
+{
+    test3();
+}
\ No newline at end of file