TM4C123G LaunchPad Ultrasonic HC-SR04

[nravirke]

Hi,
I am new to this SERIES OF TM4C123G LAUNCHPAD.
In my project, I need to Measure the Frequency & Duty Cycle of the wave. Just I was go through the code given for Ultrasonic HC-SR04.
I tried to build the same code given in the example. But It Is giving error at: ltoa(ui32ObstacleDist, chArrayDistance); & later I found that the ltoa(val, buffer, radix); is the actual Format. What is the Value for the Index.
Thanks for all your works.
They are really useful.

Thanks & Regards,
Ravi