I have been thinking of building my own motolyzer equivalent to or better than that of the latest version by Trinity.
After asking them how fast the latest version samples at, I received no response. Checking the manual does not answer my question either. After some thought, I suspect the sample rate could be as little as 10hz, but not more than 50hz. I say this as timing is usually tested at a low throttle input, say 10-20%. And given that there is a 15k rpm limit on the current motolyzer version, this I believe further supports my assumption.

Since building my own dyno with arduino, I've realized that building a custom motolyzer is also possible. I've already got a current sensor, which would be used to record the current per phase. All I need to figure out is the formula to calculate timing.

Since arduino can be set to sample at high rates, my dyno for example is currently set at 200hz which is much faster than the already expensive MiniPro, when maxed out can only achieve 50hz. At one point I considered buying one, but when I found arduino I opted to build my own. The discovery has already become a cheaper option, with better results.

Since all all sensored motors are setup with hall effect sensors, reading the interrupt is just the same as my dyno, just multiplied by three. Recording the moment one of the sensors is triggered can be done in microseconds, and the current flowing to that phase can also be recorded at the same time. All I need to figure out is how timing advance is calculated. If someone can assist, that would be great, please post your input here to share with everyone.

You just described a whole science but I agree that you can buy chips to do motor control or commutation and the documentation is good enough for you to figure out what you want to do.

sampling data at a high rate is one thing. Repeatable is what you want for most things. If you work out the delay through the power circuit, wiring, coil charge and empty and its repeatable you can manage you task processing to feed forward the end effect if its repeatable.

look for stuff on trapezoidal commutation or zero crossing point calculation.

Here is a nice starting point.
https://www.ncbi.nlm.nih.gov/pmc/art...5/#!po=35.7143

I’ll help if I can but i have a few things i need to do as well

What I am thinking of doing to accomplish this with the arduino is to read the interrupt from the sensor wire, while it is connected to an esc, simply by splitting the output of the Hall effect sensor to both. The esc controls the state of the the Hall effect sensor (on/off) and the arduino would listen to what is happening and record it via its digital input. This essentially is how a motolyzer is built.

The arduino would be configured/programmed to record data in this manner (think a spreadsheet)
Column A, Column B, Column C, column D
row 1 time stamp , interrupt time stamp, Current, Voltage
row 2 repeat all of the above
row 3 repeat again

now the trick is to use the time stamp to calculate the timing and rpm. This is what the motolyzer does.
RPM can be easily calculated post sampling, all in excel, or can be programmed with Visual Basic or java. Similar to what Bob does in RC3, also known as rc crew chief. Would just need to find what the formula would need to be and set it up in excel.

Best motorlyzer made is the “lap counter”

I cheated on my recent dive into this. I used the back emf of the non firing coil to calculate the dynamic relationship between the Hall effect and the center point of the coil. The only issue was that I expected the sensor to be a non linear relationship as rpm went up because of the hysteresis and it didnt. i wouldnt depend on my method for fine control but it did get a couple percent on the efficiency.