current sensing using lm324
If you are using a discrete comparator, you can try to change the voltage of comparison (one of the inputs of the comparator).
If your comparator is the own I/O input port of the microcontroller, a possible solution could be to use a pull up resistor (or a resistive divider with a pull up resistor) in the output of the LM324, in such way that you change the voltage window position of the amplifier voltage. For example, you can make the output vary from 1V to 3V, or 2-4V or 3-5V... so, you only must use the range that allows the correct operation of the comparator.
I hope it can help you... if does, please click helped to give me some points!