Arduino Leonardo wheel.

[Sieben]

Hi.

Arduino Leonardo wheel. FFB later on.

 

[Sieben]

Dmitry Zaharov
Thanks)

You mean exclude bleeding resistors R5, R6?

Wow, big thumbs up for trying alternative driver solution. I had similar board in mind (althougth with IRFZ44 on low side and fast optocouplers driving gates), and even designed board layout but was too lazy to build and test it.

You should give it a go too!)

 

[Sieben]

Alright. When connected to the PWM pins in Arduino, 9 & 10, the motor starts to rotates full power.
But, just runs out in one direction.... The common ground is not connected, i.m. between driver and arduino. I guess as it, and should not be connected with each other, with a common "minus".

 

[Dmitry Zaharov]

Dmitry Zaharov
Thanks)

You mean exclude bleeding resistors R5, R6?

No, they should stay. Not sure how much current Arduino can provide, therefore between gate of low-side 3205 and input pin 1K resistor should be inserted (instead of just a connection).

Alright. When connected to the PWM pins in Arduino, 9 & 10, the motor starts to rotates full power.
But, just runs out in one direction.... The common ground is not connected, i.m. between driver and arduino.

I don' think so, they should share same ground otherwise current can bleed to pins 9 and 10.

 

[Sieben]

Alright. Have got to be checked that really. And connect common together too.

There a good tutors of Lewis Loflin. There are those resistors out there, you are exactly talking about.

And some results of test. Menaged to get soft locks. Was no response with wheel check though. And mosfets become, pretty hot and went out of operations with some time. Gradually becomes hot. The mode was pwm +/-. Tested with 4 and 8khz with EMC.

 

[Dmitry Zaharov]

Alright. Have got to be checked that really. And connect common together too.

There a good tutors of Lewis Loflin. There are those resistors out there, you are exactly talking about.

And some results of test. Menaged to get soft locks. Was no response with wheel check though. And mosfets become, pretty hot and went out of operations with some time. Gradually becomes hot. The mode was pwm +/-. Tested with 4 and 8khz with EMC.

This may be because mosfets aint close in time. You may want to replace pulldown 120K resistors with 20K or even 5K to force them to close faster.

 

[Sieben]

I was suspicious to that 120k too. Should replace it. Cool!

 

[Sieben]

Add those 1k resistors, as was mentioned. Nothing so much special changes, seems to be.
The pwm from pin 10 works. It performs the soft lock and ffb in a game, ONE side. But just in a higher range of a signal as looks like and pretty strong.
With spring effect it stars to kick at 15%of spring effect.
But if pin 9 is attached, mosfets are just a toaster then. And all the same if just only one pin 9 is attached too.

Is it a matter of PWM+Dir v.s. PWM +/- ?
And shall have this connection?


120k are just are in the board and not replaced as was mentioned before.

Some know how to make the isolation to mosfets on radiator )))

 

[Sieben]

"It".

And soft lock.

 

[Sieben]

Put 4,7k instead of 120k all around. Don't know but nothing so. The ffb is like kicking. And connected only to work one side. All the same. So dat's not a solution. Find in one site, that transistors are not good for driving mosfet gates with pwm. Ready made drivers should be used.

 

[Sieben]

Find good schematics with values and calculations. And a bit an expanded version of the bridge below there.
https://www.instructables.com/id/Designing-a-Dual-40A-PWM-Speed-Controller-for-Brus/

And some more.
https://easyeda.com/beragumbo/H_bridge_driver-0912106386ef4a629d52195e5599ec80

So can be tinkered a bit to get it work right.)

 

[Sieben]

Well, got some progress with this thing. Checked and changed one of the 3205 and it starts to work much better, in terms, that now it performs the smooth work without any kicks as before. ( i.m. I check it with Wheelcheck "Simple Spring" mode on this sort of things) All the same picture as was with BTS7960 except the slightly 1% of the wheel turn with 900deg range deadzone. It is about 10deg of the wheel turn itself. Not to slightly, but still good to know. ) Now schematics looks like that, except the underlined 1k resistors out there. Should also try 1k instead of 4.7k, and smth less with of values to gates of 2n2222. May be will bring the dead zone to better picture. The 1k to gate of the low irf3205, as per initial schematics, brings no signal to it at all, so was excluded. At least all of this is true with 12V power supply.

But still do not connect the other side to the pin 9 in arduino. )))

 

[Sieben]

That must be obvious)) I recall that short circuit an Arduino some time ago, and checked the 9 pin voltage. And that goes ~5Volts constantly on idle on that pin)) Will switch to STM32.

 

[super_gt]

"It".

And soft lock.

I've always wondered how smooth this single chain drive mechanism is. When the power of the wheel is off and you turn the shaft of the steering wheel, is it smooth or you can feel the chain?

 

[Sieben]

super_gt chain drive is really absolutely smooth.

 

[Sieben]

Checked the STM32 board I've got, and it is 3.3 volts compared to Arduino's, that is used, with ~5V controlling signal. Some mosfet gate drivers should be made additionally. If not go to the Logic level Mosfets to work with STM32. Seems to be not the very best option.

The gate drivers, if not going to IC's. Hope smth like that is suitable and will work.

1. R1=2,2k, R2=100, R3=1,5k, R4=47
2. D1 — 1N4148
3. T1, T2, T3 — KST2222A
4. T4 — BC807

Also.

Fired up IRacing, and it gives good FFB. One side for now with cooked a bit, Arduiono). But it works allright absolutely. And no heat, at least in a short run. Don't know how will cope with full version, when both pins attached. Hope will be no conflicts, and fried mosfets due to that. But it is also, all is a sorted out issues. At least, if I get it right, will be all the same config, as if with BTS both pins enabled to the left right rotations attached,(LEN/REN) must work good.

 

[Sieben]

Some new mounting stuff.
And add a fan to the driver with a button activation.



New arduino board with spring test. Mosfet gate drivers, itself required, seems to be, for a pin 9. Or another mosfet ) A bit less powered then another side.

Spring test.

 

[Sieben]

Alright. A little sum up, for now. The driver is fully working!

Got to solder the mosfets maybe more carefully, without overheating the pins of the device. Changed another side IRF3205 and here we go) Also added 47 ohms to the gates of the 3205 to eliminate, (must work) the "ringing" as an LC contour. )

The step test with 300 ms & 600 ms.



360 deg for 540ms = 1.8 rev.sec = 108 rev.min
Half the standard from 200rev/mins. But at least there is a not bad result on the whole, concerning that mosfets operates with 4 volts on there gates. With the schematics just as is).

Step test - 300ms / 600ms / Cycle.

 

[Sieben]

Made the MOSFET gate driver. But it inverts the signal. So the invertor for the gate driver itself is required to this approach.

 

[Sieben]

Have got an assumption, that can only put logic levels to the N side mosfets. Both P channels 4905 have about 11volts on the gates with no signal. So they must be opening with 0, and close with 1. If i got it right)

 

[Sieben]

Regarding the mosfet gate driver from this schematic.

https://radiohlam.ru/driver_polevikov/

In order, there be no inversion of the signal, the required signal is on the vcc of the schematic. The one that is needed. And then the "out" should be connected to the common ground. The "P-channel connection". ))) Works with 3v input. And it might be even less. Logic level.)