In uart example the protocol used is RS232?

[Pablo]

I program the uart example in my board nRF51 dk. I put a osciloscope in pin 9 and the signal is a square wave between 0 al 30V. So i think that the protocol is RS232, is this correct?

[Sigurd]

No, RS232 is not used in the UART example, it uses TTL logic levels (0 - VDD).

With the RS-232 standard a logic high ('1') is represented by a negative voltage (from -3V to -25V), while a logic low ('0') is a positive voltage (from 3V to 25V). So if you want to use RS232, you need to add a RS232 transmitter/receiver, e.g. MAX232.

[sagarnayakm]

Hello, 

I doubt regarding the RS232 i mean MAX232, actually i am using app_ble_uart example with 17.0.2 version of SDK and i want ble should be connected continuously and whenever user wants to send the commands from the customized APP the device should receive it and as off now its working fine but at the same time MAX232 has uart connection with TX(P1.3) and RX(P1.4) since from the sensor board the data continuously transmitted to MCU (nrf52840) and based on the data respective action was taken but the problem is whenever i used to connect the sensor data pin to RX pin(P1.4) to MCU its disconnected from the mobile APP so how to achieve this please let me any solution for this.

thank you.