added sending unconfirmed message for RHF76

1. added AT+ command "AT+MSGHEX" and change previous RHF76_ATCMD_FMT_SEND_MSGHEX to RHF76_ATCMD_FMT_SEND_CMSGHEX

2. implement send_unconfirmed with a non-breaking approach: added int (*send_unconfirmed)(const void *buf, size_t len); event handle in lora_module_st; added int tos_lora_module_send_unconfirmed(const void *buf, size_t len); in lora_module_wrapper.c; and implement static int rhf76_send_unconfirmed(const void *buf, size_t len) in RHF76.c

3. added { "+MSGHEX: PORT:", rhf76_incoming_data_process } in event array rhf76_at_event so that the device is able to process the downlink data when it is configurated to send unconfirmed message.

4. added AT+ command "AT+REPT", and implement the static int rhf76_set_repeat(uint8_t num) to enable user to set repeat times (1-15) while using "unconfirmed message"

5. updated the instructions of implemeting up-link parser and downlink parser on the server in the file "..\board\NUCLEO_STM32L073RZ\BSP\Src\lora_demo.c"

devices/rhf76_lora/RHF76.c

@@ -154,6 +154,26 @@ static int rhf76_set_chanel(void)
     return -1;
 }
 
+static int rhf76_set_repeat(uint8_t num)
+{
+    int try = 0;
+    at_echo_t echo;
+    char cmd[14] = {0};
+    char expect[10] = {'\0'};
+    snprintf(cmd, sizeof(cmd), RHF76_ATCMD_SET_REPT, num);
+    snprintf(expect, sizeof(expect), "+REPT: %d", num);
+    
+    tos_at_echo_create(&echo, NULL, 0, expect);
+
+    while (try++ < 10) {
+        tos_at_cmd_exec(&echo, 3000, cmd);
+        if (echo.status == AT_ECHO_STATUS_OK || echo.status == AT_ECHO_STATUS_EXPECT) {
+            return 0;
+        }
+    }
+    return -1;
+}
+
 static int rhf76_set_adr_off(void)
 {
     int try = 0;
@@ -305,9 +325,14 @@ static int rhf76_init(void)
         return -1;
     }
 
+    if(rhf76_set_repeat(1)!=0){
+        printf("rhf76 set repeat times for unconfirmed message FAILED\n");
+        return -1;
+    }
+    
     at_delay_ms(2000);
     printf("Init RHF76 LoRa done\n");
-
+    
     return 0;
 }
 
@@ -377,6 +402,7 @@ __STATIC__ void rhf76_incoming_data_process(void)
 
 at_event_t rhf76_at_event[] = {
     { "+CMSGHEX: PORT:", rhf76_incoming_data_process },
+    { "+MSGHEX: PORT:", rhf76_incoming_data_process }
 };
 
 static char __num2hex(uint8_t num)
@@ -405,7 +431,6 @@ static void __hex2str(uint8_t *in, char *out, int len)
 
 static int rhf76_send(const void *buf, size_t len)
 {
-
     char *str_buf = NULL;
 
     str_buf = tos_mmheap_calloc(2 * len + 1, sizeof(char));
@@ -416,7 +441,7 @@ static int rhf76_send(const void *buf, size_t len)
 
     char cmd[100] = {0};
     at_echo_t echo;
-    snprintf(cmd, sizeof(cmd), RHF76_ATCMD_FMT_SEND_MSGHEX, str_buf);
+    snprintf(cmd, sizeof(cmd), RHF76_ATCMD_FMT_SEND_CMSGHEX, str_buf);
     cmd[sizeof(cmd) - 1] = '\0';
     tos_mmheap_free(str_buf);
     tos_at_echo_create(&echo, NULL, 0, "+CMSG: ACK Received");
@@ -427,18 +452,43 @@ static int rhf76_send(const void *buf, size_t len)
     return len;
 }
 
+static int rhf76_send_unconfirmed(const void *buf, size_t len)
+{
+
+    char *str_buf = NULL;
+    at_echo_t echo;
+
+    str_buf = tos_mmheap_calloc(2 * len + 1, sizeof(char));
+    if (!str_buf) {
+        return -1;
+    }
+    __hex2str((uint8_t *)buf, str_buf, len);
+
+    char cmd[100] = {0};
+    snprintf(cmd, sizeof(cmd), RHF76_ATCMD_FMT_SEND_MSGHEX, str_buf);
+    cmd[sizeof(cmd) - 1] = '\0';
+    tos_mmheap_free(str_buf);
+    tos_at_echo_create(&echo, NULL, 0, "+MSGHEX: Done");
+    tos_at_cmd_exec(&echo, 6000, cmd);
+    if (echo.status == AT_ECHO_STATUS_OK || echo.status == AT_ECHO_STATUS_EXPECT) {
+        return -1;
+    }
+    return len;
+}
+
 static int rhf76_close(void)
 {
     return 0;
 }
 
 lora_module_t lora_module_rhf76 = {
-    .init           = rhf76_init,
-    .join_otaa      = rhf76_join_otaa,
-    .join_abp       = rhf76_join_abp,
-    .send           = rhf76_send,
-    .close          = rhf76_close,
-    .recv_callback  = K_NULL,
+    .init             = rhf76_init,
+    .join_otaa        = rhf76_join_otaa,
+    .join_abp         = rhf76_join_abp,
+    .send             = rhf76_send,
+    .send_unconfirmed = rhf76_send_unconfirmed,
+    .close            = rhf76_close,
+    .recv_callback    = K_NULL,
 };
 
 int rhf76_lora_init(hal_uart_port_t uart_port)

devices/rhf76_lora/RHF76.h

@@ -65,7 +65,10 @@ typedef enum lora_key_type {
 #define RHF76_ATCMD_FMT_SET_KEY_TYPE_APPKEY     "AT+KEY=\"appkey\",%s\r\n"
 #define RHF76_ATCMD_FMT_SET_KEY_TYPE_APPSKEY    "AT+KEY=\"appskey\",%s\r\n"
 #define RHF76_ATCMD_FMT_SET_KEY_TYPE_NWKSKEY    "AT+KEY=\"nwkskey\",%s\r\n"
-#define RHF76_ATCMD_FMT_SEND_MSGHEX             "AT+CMSGHEX=\"%s\"\r\n"
+#define RHF76_ATCMD_FMT_SEND_CMSGHEX            "AT+CMSGHEX=\"%s\"\r\n"
+#define RHF76_ATCMD_FMT_SEND_MSGHEX             "AT+MSGHEX=\"%s\"\r\n"
+
+#define RHF76_ATCMD_SET_REPT                    "AT+REPT=%d\r\n"
 
 #define RHF76_ATCMD_SET_BAND_CN470              "AT+DR=CN470\r\n"
 #define RHF76_ATCMD_REPLY_BAND_CN470            "+DR: CN470"