Hi can anyone help a newbie with PBP.

I am trying to log data from a piece of kit that outputs its data in 'hex ascii', by this I mean that for example the number "154307" would output as "313534333037"
I can read this in as a string but how do I (simply!) convert it into numeric variables that I can perform calculation on?
Ideally, if the above was the time, I would want to get it to hours as a byte, mins as a byte and seconds as a byte.
The other problem is that the data I need to get is not just numbers, there are also letters e.g. "READY" would be "5245414459"
as I just need to log / display the letters, this would be ok converted to an ascii string

Thanks for any help

Tony