UPDATE: The mod in this Post has a problem that will cause an over current and maybe over voltage situation. Please see the corrected mod at Post 50 below.
Sounds like a good approach RaceR86.
Not sure what to make of the high current situation. Let me walk though what I did tonight just in case there is something I'm missing.
Decided to just wire up an Attiny13A by itself because I don't have room in my UF-T90 for the Nanjg 105c driver and I don't want the redundant circuits. Wired the MCU the same as the whole driver from last night. Here are a couple pics.
Looks ugly, but there are no shorts in there. So it works just like last night. All mods work fine and 9.7 amps on high. I charged up some King Kongs and put them in. All modes work fine and with the same amperage readings for all the modes except hight. High measures 13.8 amp. I didn't leave it on to see what would happen. I should note the current readings for the other modes. These are just rough approximations of what I recall. I didn't write the currents down and didn't pay close attention to the lower modes.
PWM Current
1 Too low to realy measure. Says .01 amps sometimes
3 Same as above
9 Very low. less then .05
27 About .3 amps
100 2.2 ish amps
Pulled the voltage sense resistors to see if maybe I have a short under them. Everything looks fine. Try to use the driver with no voltage sense resistors and it doesn't work (as expected). Installed one of the stock voltage sense resistors. Al modes work fine and get the same currents as above, but the resistor fries almost instantly on high. The light seems as bright as with 2 voltage sense resistors at 13.8 amps. Driver no longer works (as expected). Replace the voltage sense resistor with the remaining stock resistor just to see if process repeats. It does. Same exact behavior. It feels like the driver is going max current even with one resistor.
It's getting pretty clear whey the HX-1175B1 has such large voltage sense resistors. They are hugh. This driver was hard on the voltage sensor resistors before my Attiny swap. They were the sole source of heat before I replaced the large diode I accidentally swapped with a FET. After replaced the diode, they and the large diode produced heat.
Not sure what to do now. I guess I will try to Attiny mod one of my untouched HX-1175B1's to see what happens. I'm done a lot of experimenting on the HX-1175b. So maybe I inadvertently changed something without realizing it.