Sending file via Bluetooth SPP

antonbegovtsov
Posts: 1
Joined: Fri Jan 14, 2022 7:37 am

Sending file via Bluetooth SPP

Postby antonbegovtsov » Fri Jan 14, 2022 11:24 am

I have 2 ESP32 Dev Boards. One (call it Sender) send data to another(call it Reciver) via Bluetooth connection and SPP. Both have microSD adapters attached.
How it works:
1. Sender take command to upload file.
2. Open file and forming packets with specific size. I use 64 bytes. 1st byte of each packet is a command byte, 2-64 - data.
3. Send file to Reciver with esp_spp_write() like this:

Code: Select all

esp_log_buffer_hex("Packet is ready ",data_buff,sizeof(data_buff));
    ESP_LOGI(TAG, "Size=%d", sizeof(data_buff));
    esp_spp_write(connection_handle, sizeof(data_buff), data_buff);
4. ESP_SPP_DATA_IND_EVT happen in Reciver and Reciver copy data to buffer and call function that parse the packet.

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case ESP_SPP_DATA_IND_EVT:
ESP_LOGI(SPP_TAG, "Incoming packet");
        memmove(data_buff,param->data_ind.data,param->data_ind.len);
        esp_log_buffer_hex("Packet recieved ",data_buff,sizeof(data_buff));
        ESP_LOGI(SPP_TAG, "Size %d", param->data_ind.len);
        packet_parser();
        break;
Function packet_parser() do a lot of things but in next part:

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case 0x01: //When we RECEIVE file from phone
                if(BL_MODE == BL_COMMAND_MODE)
                {
                    int counter = 0;
                    for (int i=1;i<sizeof(data_buff);i++)
                    {
                        //packet_buffer[i-1]=buffer[i];
                        if(data_buff[i]!=0x00)
                            counter++;
                    }
                    char name[counter];
                    for (int i=1;i<counter+1;i++)
                    {
                        name[i-1]=(char)data_buff[i];
                    }
                    filename =  malloc(sizeof(name));
                    esp_log_buffer_char("Name ",name,sizeof(name));
                    esp_log_buffer_hex("Name ",name,sizeof(name));
                    memmove(filename,name,sizeof(name));
                    esp_log_buffer_char("File name recieved ",filename,sizeof(filename));
                    esp_log_buffer_hex("File name recieved ",filename,sizeof(filename));
                    //strcpy(filename, (char*)packet_buffer);
                    //Check if there is file with such name
                    if (f_check(filename ) != 0)
	                {
		                ESP_LOGI(TAG, "File already exist(write section)");
                        //Send command packet to say it
		                break;
	                }
                    ESP_LOGI(TAG, "Opening file");
                    f = fopen(file_path(filename ), "wb");
                    if (f == NULL)
	                {
                        esp_log_buffer_char("File path ",file_path(),sizeof(file_path()));
	                    ESP_LOGE(TAG, "Failed to open file for writing");
                        break;
	                }
                    ESP_LOGI(TAG, "File opened");
                    BL_MODE = BL_DATA_MODE;
                    ESP_LOGI(TAG, "BT MODE %d", BL_MODE);
                    break;
                }
If we recived a packet with 1st byte 0x01, Reciver extract data from it (Name of the file).
And here comes the problem. In this part

Code: Select all

esp_log_buffer_char("Name ",name,sizeof(name));
                    esp_log_buffer_hex("Name ",name,sizeof(name));
                    memmove(filename,name,sizeof(name));
                    esp_log_buffer_char("File name recieved ",filename,sizeof(filename));
                    esp_log_buffer_hex("File name recieved ",filename,sizeof(filename));
Log say


I (8834) Name : history
I (8844) Name : 68 69 73 74 6f 72 79
I (8844) File name recieved : hist
I (8844) File name recieved : 68 69 73 74


So in char name[] I have actual name but if I try to copy it to char* filename it copy only 4 bytes.

And it every time when I try to work with data.
If send name[] to function file_path(char* name) I still recive 4 bytes
  1. [Codebox=c file=Untitled.c]
[/Codebox].
If change packet_parser() so it recive buffer like packet_parser(char * buff) I still recive only 4 bytes.

Any idea why it dissapear?

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