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700 points elipsitz | 2 comments | | HN request time: 0.408s | source
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TaylorAlexander ◴[] No.41194755[source]
This is very exciting! For the last several years I have been developing a brushless motor driver based on the RP2040 [1]. The driver module can handle up to 53 volts at 30A continuous, 50A peak. I broke the driver out to a separate module recently which is helpful for our farm robot and is also important for driver testing as we improve the design. However this rev seems pretty solid, so I might build a single board low cost integrated single motor driver with the RP2350 soon! With the RP2040 the loop rate was 8khz which is totally fine for big farm robot drive motors, but some high performance drivers with floating point do 50khz loop rate.

My board runs SimpleFOC, and people on the forum have been talking about building a flagship design, but they need support for sensorless control as well as floating point, so if I use the new larger pinout variant of the RP2350 with 8 ADC pins, we can measure three current signals and three bridge voltages to make a nice sensorless driver! It will be a few months before I can have a design ready, but follow the git repo or my twitter profile [2] if you would like to stay up to date!

[1] https://github.com/tlalexander/rp2040-motor-controller

[2] https://twitter.com/TLAlexander

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1. Rinzler89 ◴[] No.41200089[source]
>I have been developing a brushless motor driver based on the RP2040

Can I ask why? There's dedicated MCU for BLDC motor control out there that have the dedicated peripherals to get the best and easiest sensored/sensorless BLDC motor control plus the supporting application notes and code samples. The RP2040 is not equipped to be good at this task.

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2. SequoiaHope ◴[] No.41200175[source]
> dedicated MCU for BLDC motor control

During the chip shortage, specialized chips like this were very hard to find. Meanwhile the RP2040 was the highest stocked MCU at digikey and most other places that carried it. The farm robot drive motors don't need high speed control loops or anything. We just needed a low cost flexible system we could have fabbed at JLCPCB. The RP2040 also has very nice documentation and in general is just very lovely to work with.

Also SimpleFOC was already ported to the RP2040, so we had example code etc too. Honestly the CPU was the easy part. As we expected, getting a solid mosfet bridge design was the challenging part.