The wheels above are cool, specially since they can carry a lot of weight. But, the motors are 2 x 2.5KW and the belt driven design is very open making it easy to be contaminated. The powerfully motors are more designed for speed than for driving slowly, but I will optimize that later. Position system…
The plan is to use two separate CAN Networks on my Lawn Mover – one network for motors, and one network for everything else – both using CAN HS at 1Mbps. To do this I consider upgrading XportHub. This picture show XPortHub2 w/2 CAN Ports. ISO1042 is an isolated CAN tranceiver in a SOIC8 a…
This is a new version of my 32 x IO/Servo Hat. I have always been a bit unhappy with pin-header connectors since they can be disconnected easily, so I decided to try how a surface mounted 2-pin JST worked out and voila – 32 2 pin connectors with signal and ground. This means I drop…
I am currently using DRV8301 from TI and is very happy with that one, but I want to add a 3rd Current Sensor so I can detect sensor errors and my eyes fell on DRV8353 and DRV8323 series. DRV8323 is 60V, while DRV8353 is 100V. I don’t mind the increase in voltage. The numbering is…
I recently discovered this chip (ISO1042) and wanted to share a circuit I found. This circuit is excellent, but it has two flaws: Firstly you need a small isolation coil 10-20uH between ISO 1042 and VCC1. This act as a filter so that higher frequencies used by the buck converter in ISO1042 do not disturb…
My previous entry show how to pre-calculate a Sinus table so we avoid doing this full speed because the next step is to convert this into a PWM pulse. A PWM pulse is measured in time – length – so we need to know the max length of a pulse. That is decided by the…
As mentioned in part2 I want to create a 360 degree vector table with PWM duties for A,B and C. This allows me to drive sinusoidal by simply stepping 0 to 359. To do this I create a small C application as follows: #include “stdio.h” #include “stdlib.h” #include “math.h” int main(int argc, char* argv) { FILE* fd = fopen(“vectors.cpp”, “w”); if (fd != NULL) { fprintf(fd, “alSinusVector _vector[AL3P_VECTOR_SIZE]=\n”); fprintf(fd, “{\n”); for (int i = 0; i < 360; i++) {…
In the Trapezoidal algorithm we drove the field using six steps which works, but it is very inaccurate. I would like more steps and to do that I need to use a Sinusoidal algorithm. Sinusoidal means we create a sinus wave using PWM duty, in fact we create 3 sinus waves 120 degrees apart to…
I will try to annotate the motor driver algorithms starting with a simple, brute force Trapezoidal algorithm. If you try to read papers on motor drivers you will see a lot of advanced math, but you will find very few papers explaining how simple it actually is, so I will try to do that here.…
Running a BLDC (3-phase motor) you need to insert and tune some parameters with regards to size of motor, number of winding, how much current do you output etc. But, more important is the algorithm and technique you chose matching the job at hand. You have three different algorithms (FOC, Sinusoidal, Trapezoidal) and a variety…