Open source ESC and firmware

[durok]

Originally Posted by Alka

Thanks, it can control two brushed motors at the same time too, there is a separate channel that can be used for the second input. Both motors share the same middle mosfets so the drawback is both have to be going the same direction at the same time ( but they don't have to be going the same speed). Maybe its useful for dual motor crawlers ? otherwise the second channel can control the drag brake strength.

Seriously nifty!

[punkindrublik]

Subbing. Cool stuff...

[Alka]

Added selectable bi-polar/ uni-polar PWM for brushed modes and a crude adjustable PWM dithering.
With bi-polar pwm both channels are putting out 50 percent power all the time. For the motor to go forward the duty is increased on one channel and decreased on the other. For some hardware that requires a minimum on time this allows for more resolution at low throttle.
This also how two brushed motors can be run from one speed controller both with independent forward and back .. the only drawback is the get half the voltage each so if you use a 6s battery its just about right
PWM dithering is done on a 4khz frequency injected over the 24 khz motor drive frequency.. it simply varies the power plus or minus some value to help break friction.
This will be added in github ( link on first page ) tomorrow.
Work has start on a PC configurator too!

I went to order a holmes hobbies devolver.. but it was 26 US dollars to ship to Canada. I would still like to make this my test motor but i can't pay $80 Canadian for one motor and shipping! Arrgrh !!.. I am using an outrunner from an underwater rover for my testing right now in my crawler that bluerobotics sent out (m200) but its only 500kv so its very slow and it squeaks a lot (it is meant to be run under water).

[MrAMath]

Originally Posted by self-future

Wow, this is super exciting. I always wonder why rc forums don’t cater to this kind of thing. Someone at rccrawler seriously needs to make a section for open source projects like this and also mechanical design. Maybe experimental would be a good classification?
I love tuning and a printed body, but this is another level that we should all aspire to!
Definitely going to keep up with your projects!

Yes exactly. Dangerous words for me are "wouldn't it be cool if...." My crawling buddy just rolls his eyes now. But it gives me something mechanical to work on and think through.

Current thoughts include:

-moving a dig unit to the rear axle. My R1 dig really has to work the driveshaft length to engage and disengage. Moving a toothed collar into the end of a driveshaft on the axle end might be easier.

-somehow being able to adjust ground clearance on the fly or go between 2 suspension extremes

[JatoTheRipper]

Originally Posted by Alka

Added selectable bi-polar/ uni-polar PWM for brushed modes and a crude adjustable PWM dithering.
With bi-polar pwm both channels are putting out 50 percent power all the time. For the motor to go forward the duty is increased on one channel and decreased on the other. For some hardware that requires a minimum on time this allows for more resolution at low throttle.
This also how two brushed motors can be run from one speed controller both with independent forward and back .. the only drawback is the get half the voltage each so if you use a 6s battery its just about right
PWM dithering is done on a 4khz frequency injected over the 24 khz motor drive frequency.. it simply varies the power plus or minus some value to help break friction.
This will be added in github ( link on first page ) tomorrow.
Work has start on a PC configurator too!

I went to order a holmes hobbies devolver.. but it was 26 US dollars to ship to Canada. I would still like to make this my test motor but i can't pay $80 Canadian for one motor and shipping! Arrgrh !!.. I am using an outrunner from an underwater rover for my testing right now in my crawler that bluerobotics sent out (m200) but its only 500kv so its very slow and it squeaks a lot (it is meant to be run under water).

Supposedly AMain has cheap shipping to Canada.

But I thought you and Holmes were going to work out a deal where you'd get a free Revolver?

[Alka]

Originally Posted by JatoTheRipper

Supposedly AMain has cheap shipping to Canada.

But I thought you and Holmes were going to work out a deal where you'd get a free Revolver?

John has to make a living too, I told him I would answer any questions.. no revolver necessary. I can copy and paste my code anywhere at no cost to me but John can't do the same with his revolvers! Just never knew about how much it would be to ship lol. I will check out Amain!

[JohnRobHolmes]

I'll still send you one for testing hardware and software!

I've been stuck in a loop studying software. Although I could throw this stuff on a board and watch it go with little understanding, im trying to understand it all on a deeper level. Wrote some code today though

[Alka]

Originally Posted by JohnRobHolmes

I'll still send you one for testing hardware and software!

I've been stuck in a loop studying software. Although I could throw this stuff on a board and watch it go with little understanding, im trying to understand it all on a deeper level. Wrote some code today though

That's awesome, a devolver is good enough for me! We will make a trade and I will send you some dev ESC's to play with that are easy to program and debug. (also to re-solder FETS when things go badly).

[JatoTheRipper]

Originally Posted by Alka

John has to make a living too, I told him I would answer any questions.. no revolver necessary. I can copy and paste my code anywhere at no cost to me but John can't do the same with his revolvers! Just never knew about how much it would be to ship lol. I will check out Amain!

I respect your stance!

Originally Posted by JohnRobHolmes

I'll still send you one for testing hardware and software!

I've been stuck in a loop studying software. Although I could throw this stuff on a board and watch it go with little understanding, im trying to understand it all on a deeper level. Wrote some code today though

I also respect this!

[Alka]

Super creepy..

https://youtu.be/R9KDW1Cdky0

[Voodoobrew]

So if I want to buy a board that I upload your firmware to, what would you suggest. Money not being an issue, just wanting the best, or at least one that is not going to limit me as an esc much. Don't know any thing about the boards really.

I have never done any firmware uploading except over USB.

I think your project will really get some views once you put up a start to finish tutorial that just covers what to get, how to install, and a few bits on configuring your firmware.

Sent from my SM-N950U using Tapatalk

[Alka]

Hi Voodoobrew, the firmware originally meant to be compatible with blheli_32 boards (for multirotors) but I have never tested it on any other hardware than my own contraptions. The sinusoidal start required some very fast switching mosfets though and only works on specific hardware.. This board was using the St micro STSPIN32F0 mcu. There are no commercial boards yet that will be suitable but I think this little chip is a really amazing device and we will see it more often soon.

The base firmware on github is for the f051 mcu which is used in a lot of multirotor or airplane esc's but I have no experience with any. It is pin compatible with the "wraith_32" esc's but some manufacturers are locking the mcu's so they cannot be reprogrammed with other firmware.

I don't know where to go from here. I never expected to get this far .. Right now you would have to upload code using a st-link programmer but i am looking into using a bootloader so that a simple usb-serial adapter can be used. The sinusoidal super slow stuff still needs work but I think it has potential.

I am going to solder a few more boards together and send them out to some people to start testing if you are interested. I think the firmware still has a long way to go before it is ready for a bigger roll out, and it needs some PC side configurator.

I know there are a few engineers from different manufactures that check my blog on rcgroups. If I do come up with something really good it will be in commercial esc's soon anyway since its all open.

[Fumes]

What would it take to get one of my blheli_s ESC's to work with your firmware?
Would it be possible to use information from any of the hex-files from the blheli release to use in yours?
I really love the idea of open source rc gear, hope you will continue to develop this!

[Alka]

Originally Posted by Fumes

What would it take to get one of my blheli_s ESC's to work with your firmware?
Would it be possible to use information from any of the hex-files from the blheli release to use in yours?
I really love the idea of open source rc gear, hope you will continue to develop this!

I work on it everyday ! Blheli_S unfortunately uses a specific series of 8 bit SILABS mcu. This is a very capable little chip but the programming is done in assembly.. ugh.. and its really right at the limits of its capabilities and memory space. The firmware will however work on blheli_32 esc's . Right now the pinout matches that of the wraith_32 hardware. Many _32 boards are coming write protected though and use a proprietary closed source bootloader. They really did their best to make sure no-body follows in their footsteps and develop open source firmware for this new hardware. This was done by the same people who started off by writing open source firmware too!. You can get around the write protection though so if you decide to try it send me a pm.

[Fumes]

Nice to hear that the project is still alive!

I found this thread literally hours after ordering a "noname ESC" from China last week.
I'm on a pretty tight budget so i won't be able to get a new ESC right now.
Sending you a PM though, with a link to a product so you can verify if it is compatible with your work.
That way i have something to look forward to when spring is coming.

[Alka]

I finally got around to adding serial support to the firmware ESC and the dual motor control. I have been out of action for a little while due to a medical issue but i am back working on things now. I have some Holmes Hobbies motors to play with now and have a bunch of new ideas. I will start doing some real testing on them and will put some videos up of the progress. Here is the dual motor setup in action and a brief explanation.


https://www.youtube.com/watch?v=4Z1Wbk2WS4s


This might also work for saving some weight and complexity in dual motor on axle setups. The voltage is divided if you want full independent forward and reverse ( one motor can be going forward while the other is going backward). If both motors are going in the same direction at the same time ( I think this might be the case with dual motor on axles ) then the full voltage range can be used. Both motors still have independent speed control but you won't be able to drive one forward while the other one is reversing.
let me know what you think !

[JatoTheRipper]

Originally Posted by Alka

Super creepy..

https://youtu.be/R9KDW1Cdky0

Super impressive!

[Alka]

Originally Posted by JatoTheRipper

Super impressive!

Thanks!, JRH sent me some awesome motors and the sinusoidal startup is even better on the revolver. I have some more videos on my channel using another outrunner and will have some up of the revolver as soon I can get outside and film. The revolver is also silent at startup just like that one was.

[JatoTheRipper]

Originally Posted by Alka

Thanks!, JRH sent me some awesome motors and the sinusoidal startup is even better on the revolver. I have some more videos on my channel using another outrunner and will have some up of the revolver as soon I can get outside and film. The revolver is also silent at startup just like that one was.

That's awesome he did that for you!

If you managed to make the Revolver silent at startup then you pulled off something big! I'm looking forward to your videos.

[Alka]

You convinced me to get up off the couch ( off work on medical right now) I went out and did a quick little video of the revolver. The kids are at school so I have no cameraman and the controller is a dual stick ( air craft) so it took me a few minutes to cobble together a little mount for the phone for a tripod. The controller is really hard to modulate on the low end with the sticks. A good radio with expo would be nice here. It's still got some things to complete and a few kinks but its getting really close.

And a big thank you to John Holmes for sending the motors out to me. Absolultely blow away by them ! My crawlers are not worthy of these motors.

https://www.youtube.com/watch?v=PhMLIHtQlAo