In embedded code for PSOC you can use sprintf() which prints to a buffer, that then
can be used over I2C, UART, USB, SPI....whatever. It is the equivalent of printf to a
console, like in windows. Uses essentially same formatting string as printf.
To add to Dana's post, you can see the messages sent using printf in the these BLE projects over an USB-UART COM port. This COM port is emulated over the PSOC 5LP Kit Programmer (present on the kit). Connect the kit to your PC -> Open a COM port terminal and select the port -> Select the Baud rate as set by the example project (most of the time it is 115200 bps). You should see the debug messages on the screen. Also, for some projects, the same screen will acts as input to BLE device for triggering certain actions.
Thanks for this information.
I jacked in my PSoC 4 BLE Pioneer kit.
Setup a console to the UART via PuTTY,
Fired up PSoC Creator and flashed the PSoC BLE and all the printf appear in the PuTTY session.
This is just what I was looking for, thanks Riot.
Glad to be of help! :)