We worked on communications this week-end. Master Node (Mega 2560 in the center) sends via I2C the Voltage level to the Uno running the TFT Touchscreen that will be mounted in the dashboard.
The Master Node now can also receive via one of it’s hardware Serial Port Amperage level data from the Mega2560 on the left (stand-in for Leaf Maple).
Next step is to figure out how to send both Amperage & Voltage via I2C and extract both data points. Then RPM data can be added to the data stream.
Software, Software, & more Software.
This was a Software week-end and we are proud to report that after much discussion & collaborative effort, we have produced our own Power Scaling function that returns an integer based on 6 floats fed to it.
It is much smaller & more efficient than the Arduino fscale function that inspired us, combines all the functionality of scale with power & reverse power (x exponent y & x exponent 1/y) and should do our work just fine in driving these 6 MOSFETs of our Sanderson Dynamic Drive 2.0
P.S. We are down to only 1 array and we are using only 120 samples of pi now.
3 Phases of AC Power at 120 samples.
In our new code, we are actually using only 2 arrays (one for Sine High & one for Sine Low), each having a total of 180 samples. The Leaf Maple seems to have no problem at all doing the math to interpolate the B & C phases on the fly. Could it actually also calculate PI for all 3 phases on the fly??? I guess we will need to find out…
While the behavior of the Sanderson Drive 2.0 may not have changed much in the last few days, tonight marks a change in the software code that reduces by a significant amount both the length of the code (number of lines of program) and the space of the code (quantity of variables/arrays). Both of these factors contribute to more efficient software that is easier to read & comprehend/troubleshoot.
After a few Ubuntu (Linux) IDE issues on 1 laptop, we moved to a good old Win XP laptop running the original Leaf Maple IDE and successes were quick & progressive.
Very soon, we needed to add a second 12 Volts Battery to the 3 Phase AC Motor as it was running out of steam with our modified code.
A lot still needs to be done to our sketch before we can drive the Electric Truck to the store, but we are already feeling the day will soon come.
Successful evening! Watch James describe the Sanderson Dynamic Drive 2.0 PCB & its operation.
Moving up in Voltages as lower voltage tests are successful. We are now driving the 3 phase AC motor through our IGBTs using one 12 Volt battery only.
Home made Transformer finally mounted on our home made PCB. With a 9 Volt battery to power the Leaf Maple & a 9 Volt battery to power the AC Motor, we are running the initial integration tests for the Sanderson Drive 2.0 starting with inexpensive MOSFETs to preserve our IGBTs.
Now that our transformer is finally all wound up & completed, it’s time to apply some power to our Sanderson Dynamic Drive Leaf Maple Shield and start testing voltages to make sure it’s behaving properly.
So far so good… We are one step closer to Integration testing with an actual 3 phase AC motor…
Sorry, not much blogging over the holidays, we both had quality time in our respective families.
This is our User Interface Prototype for the 2.0 Sanderson Dynamic Drive.
It’s getting close to integration time.
It already operates using I2C communications between the Arduino UNO running the Touchscreen TFT LCD and the Mega feeding the values and controlling the Leaf Maple 32 bit (which is integrated on our custom Motor Shield).