Buck-Boost LED Driver - Current Sense Resistor Trimming

[A.Huggy]

I'm working on an LED driver for a car headlight project.  The target current for the LED's is 3A, but during testing, I never saw more than 2.1 amps. 

The LED current limit is set by a current sense resistor with a value of 0.025 ohms.

Since the circuit is on a breadboard right now, I consider myself lucky the circuit works at all, and even luckier that the current is as close to the target as it is.  But this got me thinking, what steps do I need to take to account for resistance in the PCB traces?  Can I somehow adjust the current sense resistor after the circuit is assembled? A pot?  or select the value of the resistor after I can do measurements on the actual board?  Otherwise, it seems like there would be too many variables to account for to hit the target current on the money without some adjustment after assembly.

Thanks for the help 


Schematic:
U1 is an LM3421
Rcs is current limit
Rsense is target current

[Signal32]

A schematic of what your circuit is would be useful for suggestions.
But yes, you can adjust the op-amp input voltage with a potentiometer, like this:

[Signal32]

Take a look at the datasheet for your IC, page 14.
Also It's not recommended to make major edits to your post(adding the schematic) without posting a reply. Ppl that could have helped will not know that you change anything.

[A.Huggy]

Thank you for the advice.  I meant to post a reply earlier but got interrupted.

I'll reread that section of the datasheet as well as the section on overcurrent protection.  I guess instead of adding a pot inline with Rsns, I would add it inline with Rcsh.