Help in reduce circuit losses

[GH Crash]

Any suggestions on how to reduce the resistance of the attached circuit.

A supercapacitor (EDLC) is used to power a small motor. There is an ATTiny85 chip in the circuit that is used as a timer and a PWM controller for the motor. The problem that I'm loosing about half a volt between the capacitor's voltage and the voltage across the motor's leads. I need to minimize losses in the circuit as much as possible.

Can you suggest means to reduce voltage loses to the motor?

 

[GH Crash]

Vincent,
I will PM the code to you. But it will be an older version of the code, as the it is under revision at this time.

 

[vidalv]

Thanks George, as I understand the R7 potentiometer fix the run time cutoff (10 mn) and R6/C5 is to filter the input signal from PWM motor to UC using internal ADC via Analog measurement. If you are lucky to have an oscilloscope, look at the signals on each side of R6 and you will understand what this filter is for. The PWM output frequency of Attiny85 is 490Hz, with 0 to 255 value to move PWM from 0 to 100%. Use of Schottky diode (for low Vf) and polarised capacitor should be better (10 to 47uF) but if this work it's Ok.
here an example of DC/DC converter using Attiny85, Mosfet, diode and Capacitor :

 

[GH Crash]

R7 is a pull down resistor on the speed potentiometer. If BP is low, used stored value, if positive, then read and store value from pot.

No Oscilloscope.

I'd rather keep a discussion of the coding outside this thread. This thread deals with the physical circuit.

 

[vidalv]

An example :

 

[vidalv]

Ok, wire removed on R7 to VCC :