What would be the current recommended driver for a pair of ~350w @36v hoverboard motors? With I2C or SPI control? Is there a good solution for mounting encoders? Are the halls adequate?
I’m drawn to using one @runger or Valentine’s creations, largely for the amusing names & open hardware, but also the apparent quality. @runger @Valentine I don’t think you’ve done a dual channel board in this range yet?
Somewhere in the middle of the cheap/good spectrum would suit me.
For hoverboard, I believe you may need a lot more than 10A, no? I’m using the HackJammer on a hoverboard motor and it draws significant amounts of current. Also, I dis-assembled a hoverboard and it has MOSFETs way over 10A, more like 60A+ (http://tsinghuaicwx.com/upload/cn/propdf/TTP95N68A.pdf). Also the boards were separate, and connected with cables, not dual-board. So to summarize, you probably just need two high power minimum 30A+ boards, with MOSFETs capable of 60A+, and connect them with a simple I2C cable to communicate.
Please note, the HackJammer needs a low voltage buck step-down re-design, the LDO will overheat at 36V. I’m extremely busy these days, haven’t had a chance to do that. For time being I got away with a small LDO heatsink, but that’s not a very serious solution.
Cheers,
Valentine
Thanks, I’d read they were 350w motors, I guess that’s nominal…
I was looking at the hackjammer is it around $100 in small quanties? I’m actually planning to use four motors, so whilst not impossible it would start to add up.
Looking at the BOM the STM chip is around $25 of those dollars?
What functionality would you have to sacrifice with a $5 ESP S3 in its place?
I believe it’s around $60.
You can use the GD clone. A lot cheaper.
No idea. I never liked ESP to begin with. I said if you really don’t want to pay for the STM you can get a clone.
Cheers,
Valentine
If anyone’s interested PCBway is quoting $86 each on a 20pc order with no discount applied. Based on this BOM
Using GD32F103CBT would reduce to ~$68 each.
If a C2760489 can replace the C9932 price would drop to ~$56
Hall sensors have less precision that magnetic encoder, but it will run simpleFoc fine. Performance will probably degrade on low speeds due to less resolution. It all depends on your usecase.
As for the mosfets in the hoverboard mainboards, they are often around 70v 100a - the one I have that I can read the markings has STP110N7F6, and I have two boards without any markings on the mosfets, but I assume they are 60-70v around 100A as well
My application is driving across a field slowly and accurately
Would these motors using “Integrated 3200 PPR quadrature encoder” be suitable? I get a bit lost in the terminology 'RoboWheel Hub Motor for Robotics
Yup, they’re really nice. They should work no problem. 3200PPR is a lot, should be very accurate…
There has been some poor reviews of the ESP32 ADC. It’s the old “what you pay for is what you get”. It really depends on what you wish to achieve. ENOB - Effective Number Of Bits and noise does matter.
From what I gather the manufacture is trying to improve the ESP32 ADC, but having a radio and ADC in the same package is just difficult to achieve.
Maybe someone with extensive experience with these modules can comment on this ?
Yes, it can. I’ve tested it on another board. However the hackjammer assumes the Allegro chip and IIRC it will need a small rework. There was some difference about 5v vs 3.3v on the chip supply, don’t remember. It’s very minor but still a rework.
You are correct. Especially since the WROOM mini-boardlets come with a faraday cage which traps all EMR inside. Like, having your ADC inside a microwave oven. Have you ever tried to boil an egg inside a microwave oven? It’s a rhetorical question.
Cheers,
Valentine
Looks like for 4x these are $90 each from China inc postage. with the 3200PPR instead of hall. I think I’ll get some to play with.
