What output are you seeing? Does the code get through setup()? A post containing the output would be useful.
This (which is missing a comma)
char adc_sv[30] = {'T', 'h', 'e', ' ', 'a', 'd', 'c', ' '' ', 'v', 'a', 'l', 'u', 'e', ' ', 'i', 's', ' ', '\0'}; //adc_step value
could more easily be written as
char adc_sv[] = "The adc value is"; //adc_step value