In my project I am supposed to develop a software for a hardware given by the customer. and he wants me to supply him programmed Microcontroller ICs.
How should I charge him?

I much prefer an hourly rate, but a lot of clients insist on a price up front.
To illustrate, on "up front pricing" I have ended up making between $270 (glorious) and $7 (awful) per hour it actually took to do the work.

A true story:
A friend of mine contracted to create a hotel door lock system and when done presented the customer with a bill for $18.000. The customer said "i can not pay that, can we do something else" My friend, reluctantly, agreed to $5 per lock sold. Lo and behold, they sold more than 50.000 locks.

Mak, up front is a gamble, if you do not have the strength to take the gamble, refuse.

My rule is:
Do the best i can to figure out how long it will take to do it, then, based on what I sense re the customers "quality and permanence of specification" double or triple it.

I have yet to do anything where the customer did not change the specs and assume that was included in the price.

Erik