Let's begin with [communication module](http://rusefi.com/forum/viewtopic.php?t=215)
![Frankenstein Communication Module](Hardware/Frankenstein/comm_module.png)
I'm impatient so P352 SD card module goes on first. Together with the right 25x2 header (P51/P353/P402) this gets me a working SD card. Hurray, this board is not a total failure! Now it's time to C357 to make things right.
While we can use the MAX9926 VR chip for Hall sensor, the small chip is a hard to solder and the chip is relatively expensive - so I'd rather use op-amp channels for Hall sensor input. I have two Hall sensors so I would build two identical channels.
![Hall Input Op Amp](Hardware/Frankenstein/hall_input_op_amp.png)
Both would use U203 quad op-amp
C291 is 0.1uF
C310 & C320: input RC filter 10000PF/0.01uF
Inp11 would be trigger channel1: R310 1K pull-up, R311 500K pull-down, R312 10K current limiting, R313 100 smth, R314 1.5K & R315 1.5K voltage divider.
Inp12 would be trigger channel2: R320 1K pull-up, R321 500K pull-down, R322 10K current limiting, R323 100 smth, R324 1.5K & R325 1.5K voltage divider.
For trigger channel 1 there will be an ugly yellow wire between W211 and PC6, and for second channel it would be a green wire between W212 and PA5
### step 3: Analog Inputs
The legend on the back assigns throttle position sensor to INP2 (stm pin PA3/ADC channel 3), intake air to INP3 (stm pin PC3/ADC 13) coolant temperature sensor to INP4 (stm pin PC1/ADC 11).
Inp2 (stm pin PA3/ADC3) would be throttle position sensor: no pull-up, R221 500K pull-down, R222 10K current limiting, R223 100 smth, R224 1.5K & R225 1.5K voltage divider.
Inp3 (stm pin PC3/ADC13) would be intake air: R230 ??? pull-up, no pull-down, R232 10K current limiting, R233 100 smth, R234 1.5K & R235 1.5K voltage divider.
Inp4 (stm pin PC1/ADC11) would be coolant temperature sensor: R24x ??? pull-up, no pull-down, R242 10K current limiting, R243 100 smth, R244 1.5K & R245 1.5K voltage divider.
Inp1 (stm pin PA1/ADC1) is my MAP sensor: no pull-up, R211 1K pull-down
R252 10K current limiting, R253 100 smth, R254 1.5K & R255 1.5K voltage divider.
### High side driver
![Frankenstein High Side Circuit](Hardware/Frankenstein/high_side.png)
C601, C602 & C603 are 0.1uF
R609, R612 - 100R
With the current issue - we've used MSOP case by mistake, this one is hard to solder. Be sure not to use too much paste. Not sure if you should even try it with soldering wire.
There is no SD module part number from a major US supplier. TODO: figure this out, but just get them on eBay - see [forum thread](http://rusefi.com/forum/viewtopic.php?f=4&t=215&start=10#p4896)