添加写三码验三码任务，实现0x20任务，完成任务插槽机制

添加文件 tran_for_broadcast.c

source/elec_det/elec_task_slot.c

@@ -57,6 +57,7 @@ void *task_slot_init(void)
     t=calloc(1,sizeof(task_slot_def));
     app_variable("task_slot",t,0);
   }
+  t->current=t->head;
   return t;
 }
 
@@ -90,18 +91,35 @@ task_def *task_slot_next(void *context,uint8_t slot_index)
   if(t==0){
     return 0;
   }
-  task_node *n;
-  while(t->current){
-    n=t->current;
-    t->current=n->next;
-    if(n->task.slot_index==slot_index){
-      return &n->task;
+  task_def *n;
+  while(n=task_slot_next_item(t),n!=0){
+    if(n->slot_index==slot_index){
+      return n;
     }
   }
   return 0;
 }
 
 
+// 找到下一个
+task_def *task_slot_next_item(void *context)
+{
+  task_slot_def *t=context;
+  if(t==0){
+    return 0;
+  }
+  task_node *n=0;
+  if(t->current){
+    n=t->current;
+    t->current=n->next;
+    return &n->task;
+  }
+  return 0;
+}
+
+
+
+
 int task_slot_add_err(void *context,uint8_t err)
 {
   task_slot_def *t=context;
@@ -127,4 +145,16 @@ int task_slot_add_err(void *context,uint8_t err)
 
 
 
+// 获取异常代码表
+int task_slot_err_table(void *context,uint8_t **table)
+{
+  task_slot_def *t=context;
+  if(t==0){
+    return 0;
+  }
+  if(table) *table=t->err_table;
+  return t->err_num;
+}
+
+