>I'm having difficulty coming up with specific
>problems to evaluate programming skills.
>

Rather than asking for actual software, try doing some scenarios. I am 
assuming you are looking for an embedded systems programmer here.

e.g.
Scenario
requirements UART, I2C, data requires time stamp.

What interrupts would you use, how would you set up interface parameters?

(looking for timer and UART interrupts, possibly I2C interrupt, use of 
EEPROM to store interface parameters).

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist