Since your doing a ratio of 200 steps for 200 mA, wouldn't your objective be to keep adjust duty steps for to maintain mA. So for example, a VE setting of 110 would translate a duty cycle of 10/200 (10 steps of 200), or 10ma. With a decrease in voltage you would have to change the duty to maintain mA using the formula 10 * (v1 / v2) where v1 is 13v, and v2 is the current voltage. An example if voltage dropped to 12v.
10 * (13v/12v) / 200= 10.83 steps
To confirm with Ohms law we shouldhave the same mA result:
Base mA calc with 13v
10 * (13v/13v)/200 * 13v / 65ohm = 0.01A or 10mA
Adjusted mA calc with 12v
10 * (13v/12v)/200 * 12v / 65ohm = 0.01A or 10mA
Given there is a simple relationship between VE settings and the +-200 steps the following simple formula should address voltage (DPR calc considered here):
If VE >= 100
PWMDTY1 = (VE-100) * (13v / curV)
PWMDTY2 = 0
Else (VE <100)
PWMDTY1 = 0
PWMDTY2 = (100-VE) * (13v / curV)
VE = adjusted VE based on other calculation factors
curV = current battery voltage
PWMDTY1 /2 = duty setting out of 200 steps for INJ 1 and 2.
This is for discussion only, and I'm still not yet 100% sure how your duty calcs are done.
Let me know your thoughts.
P.S. wanted to be first to post in your forum.