Example code for transmitting data from nrf51822 to mobile app

[adrianwong]

Can anyone please help me on this? I struggling in transmitting string and numbers from nrf51822 to mobile app through BLE. I need some sample code. thanks.

uint8_t numbers = 80;

GattCharacteristic characteristic2(service1_rx_uuid, (uint8_t *)numbers, sizeof(numbers), sizeof(numbers), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);

ble.updateCharacteristicValue(characteristic2.getValueAttribute().getHandle(), &numbers , sizeof(numbers));

Based on the code above, I keep on getting : 'P' rather than 80.

Please help!

[adrianwong]

BLE.txt

Yes, I know. How can display the number 80 on phone? Any suggestion on the code side?

[monpetit]

Isn't it an issue on mobile programming?

[adrianwong]

is it possible to complete it on firmware side?

[monpetit]

Like this?

static uint8_t nus_buffer[20];
uint8_t numbers = 80;

sprintf((char*)nus_buffer, "%u", numbers);
ble.updateCharacteristicValue(characteristic2.getValueAttribute().getHandle(), (const uint8_t*)nus_buffer, strlen((const char*)nus_buffer));

[adrianwong]

after editing the code according to what you have suggested, nothing printed out at the mobile app. Any other suggestion? For your information, what i trying to do is my mcu will collected some data from sensor which is float number and I wanted to transmit it over to mobile app via BLE. Kindly advice.

[monpetit]

Which service of BLE do you use? Nordic UART Servie(NUS), or anythins else? I assumed that you are using NUS.