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TinyDuino Processors & TinyShields / Bluetooth Tutorial

« on: January 29, 2014, 08:48:07 PM »

Hey guys.
I could seriously need a tutorial on how to send data from the tinyduino to a processing sketch via the ble module.
I tried copying the code to my board and my BT4.0 dongle could find the device. I connected to it, but that's it. Sometimes the board led blinks twice, meaning it's connected, sometimes not. I have not found a way of definitely connecting it.

Troubleshooting is pretty hard for me, because I do not understand the code. I tried looking up some documentation, but I cannot see how this is working. I took a look at the Bluegiga API documentation but that didn't help.

My problem for starters is the boot response function:

Code: [Select]

void my_ble_evt_system_boot(const ble_msg_system_boot_evt_t *msg) {
    #ifdef DEBUG
        Serial.print("###\tsystem_boot: { ");
        Serial.print("major: "); Serial.print(msg -> major, HEX);
        Serial.print(", minor: "); Serial.print(msg -> minor, HEX);
        Serial.print(", patch: "); Serial.print(msg -> patch, HEX);
        Serial.print(", build: "); Serial.print(msg -> build, HEX);
        Serial.print(", ll_version: "); Serial.print(msg -> ll_version, HEX);
        Serial.print(", protocol_version: "); Serial.print(msg -> protocol_version, HEX);
        Serial.print(", hw: "); Serial.print(msg -> hw, HEX);
        Serial.println(" }");
    #endif

    // set advertisement interval to 200-300ms, use all advertisement channels
    // (note min/max parameters are in units of 625 uSec)
    ble112.ble_cmd_gap_set_adv_parameters(320, 480, 7);
    while (ble112.checkActivity(1000));

    // USE THE FOLLOWING TO LET THE BLE STACK HANDLE YOUR ADVERTISEMENT PACKETS
    // ========================================================================
    // start advertising general discoverable / undirected connectable
    //ble112.ble_cmd_gap_set_mode(BGLIB_GAP_GENERAL_DISCOVERABLE, BGLIB_GAP_UNDIRECTED_CONNECTABLE);
    //while (ble112.checkActivity(1000));

    // USE THE FOLLOWING TO HANDLE YOUR OWN CUSTOM ADVERTISEMENT PACKETS
    // =================================================================
#if 1
    // build custom advertisement data
    // default BLE stack value: 0201061107 e4ba94c3c9b7cdb09b487a438ae55a19
    uint8 adv_data[] = {
        0x02, // field length
        BGLIB_GAP_AD_TYPE_FLAGS, // field type (0x01)
        BGLIB_GAP_AD_FLAG_GENERAL_DISCOVERABLE | BGLIB_GAP_AD_FLAG_BREDR_NOT_SUPPORTED, // data (0x02 | 0x04 = 0x06)
        0x11, // field length
        BGLIB_GAP_AD_TYPE_SERVICES_128BIT_ALL, // field type (0x07)
        0xe4, 0xba, 0x94, 0xc3, 0xc9, 0xb7, 0xcd, 0xb0, 0x9b, 0x48, 0x7a, 0x43, 0x8a, 0xe5, 0x5a, 0x19
    };

    // set custom advertisement data
    ble112.ble_cmd_gap_set_adv_data(0, 0x15, adv_data);
    while (ble112.checkActivity(1000));

    // build custom scan response data (i.e. the Device Name value)
    // default BLE stack value: 140942474c69622055314131502033382e344e4657
    uint8 sr_data[] = {
        0x14, // field length
        BGLIB_GAP_AD_TYPE_LOCALNAME_COMPLETE, // field type
        'M', 'y', ' ', 'A', 'r', 'd', 'u', 'i', 'n', 'o', ' ', '0', '0', ':', '0', '0', ':', '0', '0'
    };

    // get BLE MAC address
    ble112.ble_cmd_system_address_get();
    while (ble112.checkActivity(1000));
    BGAPI_GET_RESPONSE(r0, ble_msg_system_address_get_rsp_t);

    // assign last three bytes of MAC address to ad packet friendly name (instead of 00:00:00 above)
    sr_data[13] = (r0 -> address.addr[2] / 0x10) + 48 + ((r0 -> address.addr[2] / 0x10) / 10 * 7); // MAC byte 4 10's digit
    sr_data[14] = (r0 -> address.addr[2] & 0xF)  + 48 + ((r0 -> address.addr[2] & 0xF ) / 10 * 7); // MAC byte 4 1's digit
    sr_data[16] = (r0 -> address.addr[1] / 0x10) + 48 + ((r0 -> address.addr[1] / 0x10) / 10 * 7); // MAC byte 5 10's digit
    sr_data[17] = (r0 -> address.addr[1] & 0xF)  + 48 + ((r0 -> address.addr[1] & 0xF ) / 10 * 7); // MAC byte 5 1's digit
    sr_data[19] = (r0 -> address.addr[0] / 0x10) + 48 + ((r0 -> address.addr[0] / 0x10) / 10 * 7); // MAC byte 6 10's digit
    sr_data[20] = (r0 -> address.addr[0] & 0xF)  + 48 + ((r0 -> address.addr[0] & 0xF ) / 10 * 7); // MAC byte 6 1's digit

    // set custom scan response data (i.e. the Device Name value)
    ble112.ble_cmd_gap_set_adv_data(1, 0x15, sr_data);
    while (ble112.checkActivity(1000));

    // put module into discoverable/connectable mode (with user-defined advertisement data)
    ble112.ble_cmd_gap_set_mode(BGLIB_GAP_USER_DATA, BGLIB_GAP_UNDIRECTED_CONNECTABLE);
    while (ble112.checkActivity(1000));
#endif

    // set state to ADVERTISING
    ble_state = BLE_STATE_ADVERTISING;
}
If I uncomment the "// USE THE FOLLOWING TO LET THE BLE STACK HANDLE YOUR ADVERTISEMENT PACKETS" section and instead comment the preprocessor if, the whole sketch is not working. So I tried understanding what is happening inside the condition. The adv_data array is a complete mystery to me. The sr_data array is a bit clearer but I don't get why the field length attribute is 0x14. And the biggest mystery is still, why the sketch works after this.

I added a system hello response and it works. If I let the ble stack handle my advertisement packets this won't work. I get a timeout.

The next thing I can't figure out is the simplest thing. IF I am connected, how do I send data to my pc?

I am really desperate because I need this for a project at university and I didn't think this would this complicated. I am willing to learn, but I need some guidance since I can't find any on the internet. Please help me figure this out.

edit:
Oh and by the way: I have revision 2 of the bluetooth board.