Kakute F4 as the next FC on the RCExplorer store?

[jihlein]

KAKUTEF4V2 UPDATE

The Kakute F4 V2 will not be suitable for a tricopter. There’s only 2 timer banks supporting the 4 PWM outputs, and they are not divided up in way suitable for separate protocols going to the 3 motors and 1 servo. It would work for a bicopter. Unless I’m mising something, it’s game over for the KakuteF4V2. I was thinking too hard about the bicopter when I first looked at the timer hardware usage.

DEF_TIM(TIM3, CH3, PB0, TIM_USE_MOTOR, 0, 0), // S1_OUT – DMA1_ST7
DEF_TIM(TIM3, CH4, PB1, TIM_USE_MOTOR, 0, 0), // S2_OUT – DMA1_ST2
DEF_TIM(TIM2, CH4, PA3, TIM_USE_MOTOR, 0, 1), // S3_OUT – DMA1_ST6
DEF_TIM(TIM2, CH3, PA2, TIM_USE_MOTOR, 0, 0), // S4_OUT – DMA1_ST1

Note outputs 1 and 2 driven off timer 3, and outputs 3 and 4 driven off of timer 2. This is how the timer peripheral on the F4 controller is actually used, and can’t be remapped.

For grins, I looked at the Matek405Ctr.

DEF_TIM(TIM3, CH1, PC6, TIM_USE_MOTOR, 0, 0), // S1 UP(1,2)
DEF_TIM(TIM8, CH2, PC7, TIM_USE_MOTOR, 0, 1), // S2 UP(2,1)
DEF_TIM(TIM8, CH3, PC8, TIM_USE_MOTOR, 0, 1), // S3 UP(2,1)
DEF_TIM(TIM8, CH4, PC9, TIM_USE_MOTOR, 0, 0), // S4 UP(2,1)
DEF_TIM(TIM2, CH1, PA15, TIM_USE_MOTOR, 0, 0), // S5 UP(1,7)
DEF_TIM(TIM1, CH1, PA8, TIM_USE_MOTOR, 0, 0), // S6 UP(2,5)

There are six channels on this one. The first four are easily accessible, and support what we need for a tricopter, servo on channel 1, on an independent timer from the the 3 motors on channels 2 thru 4. For the bicopter, you would need to bring either channel 5 or 6 into play. But there’s other issues with the Matek that make it less than ideal too. The built in PDB is nice, but the form factor increases slightly, and you still need the baby PDB to get 6 volts for the servo for example.

I guess one requirement we can layout is that the candidate F4 must play nice with the Baby PDB so the servo(s) can be fed 6 volts.

[RCExplorer – David]

Aw man 🙁 I didn’t think about that! All I had in my head was the bicopter.
Thanks for noticing it @jihlein

How about the STD version of the Matek?
http://www.mateksys.com/?portfolio=f405-std
Has pins for I2C and all 6 PWM’s are are on pins as well.

I am not liking the hard mounted ICM20602.
Price is good though.

Crap I was so set on the Kakute 🙁

[jihlein]

Matek405Std looks very similar to the Matek405Ctr, biggest difference from a firmware point of view is the gyro. I’ve attached a product selection guide to the different Invensense motion chips so you can see the relative differences between them.

While I’ve no direct experience with the ICM-20602, the Matek405Std could support Bi/Tri/Quad configurations, and could probably do navigation too. I want to look a the details a little further, but I think it would pair nicely with the Baby PDB.

Might be worth getting a few of these into some of the RCE copters and see how it performs overall. I would be willing to create a dRonin target to help support that.

Other opinions?

Attachments:

1. 

   product-selector-motion_1.pdf
   

[RCExplorer – David]

Very nice spreadsheet! The 20602 seems like a very good gyro judging by the specs (unless I’m misreading them)

Thank you very much for offering to make a dRonin target for it 🙂 That would be sweeeet!

I’m going to doublecheck against the datasheet to see if things look good on that side too.
Would be great to be able to run dual servo feedback without any issue, even though we don’t have that implemented yet.

[RCExplorer – David]

Hmm I might be missing something but the MatekF405 target doesn’t have any mention of the ICM-20602 gyro. Can’t find any other target for the Matek F405-STD. I’m confused. But assuming the rest is the same we have ADC on;

#define USE_UART1
#define UART1_RX_PIN PA10
#define UART1_TX_PIN PA9

#define USE_UART2
#define UART2_RX_PIN PA3 – ADC
#define UART2_TX_PIN PA2 – ADC

#define USE_UART3
#define UART3_RX_PIN PC11
#define UART3_TX_PIN PC10

#define USE_UART4
#define UART4_RX_PIN PA1 – ADC
#define UART4_TX_PIN PA0 – ADC

#define USE_UART5
#define UART5_RX_PIN PD2
#define UART5_TX_PIN PC12

These are the already defined ADC’s on the board:
#define VBAT_ADC_PIN PC5 – ADC
#define CURRENT_METER_ADC_PIN PC4 – ADC
#define RSSI_ADC_PIN PB1 – ADC
The RSSI pad being the obvious one to use for one feedback wire.

None of the motor outputs:
DEF_TIM(TIM3, CH1, PC6, TIM_USE_MOTOR, 0, 0), // S1 UP(1,2)
DEF_TIM(TIM8, CH2, PC7, TIM_USE_MOTOR, 0, 1), // S2 UP(2,1)
DEF_TIM(TIM8, CH3, PC8, TIM_USE_MOTOR, 0, 1), // S3 UP(2,1)
DEF_TIM(TIM8, CH4, PC9, TIM_USE_MOTOR, 0, 0), // S4 UP(2,1)
DEF_TIM(TIM2, CH1, PA15, TIM_USE_MOTOR, 0, 0), // S5 UP(1,7)
DEF_TIM(TIM1, CH1, PA8, TIM_USE_MOTOR, 0, 0), // S6 UP(2,5)

So one of the UART 2 or 4 pins could be used.
Hope I did that right 🙂

[RCExplorer – David]

Terje just tried the Kakute on the Bicopter and it seems to work well!
He also pointed out that the LED strip pin is on a different timer so it should work for the tricopter as well?

[jihlein]

“He also pointed out that the LED strip pin is on a different timer so it should work for the tricopter as well?”

Yes it could, if you want to use pins differently from the silkscreen and board manual. Was trying to avoid that if possible as it’s just another point of confusion down the road from what I’ve seen.

There’s pro’s and con’s to each board. If we ignore the silkscreens and use pins to our advantage, this is how I see it breaking out:

KakuteF4V2
bi/tri/quad support
current/voltage/rssi/fdbk2 (fdbk optional on either uart4 tx or rx)
no ppm receiver
no external i2c (limits use for navigation)
icm20689 gyro

Matek405Std
bi/tri/quad support
current/voltage/rssi/fdbk2 (fdbk optional on either uart4 tx or rx or uart2 tx)
ppm receiver
external i2c
icm20602 gyro (this is what the Matek spec sheet says, I believe it to be register compatible with MPU6000)

Neither’s a perfect fit, but both can be made to work. Gyro chips are somewhat unknown, but seems like the KakuteF4V2 behaved well for @Terje.

I can make either work with dRonin.

[RCExplorer – David]

I’m leaning towards the Matek at the moment.
The pads are a pain and I’ll probably get some support tickets about it, but the features are nice 🙂

[Kevin_Erik]

The Fixed-Wing PDB FCHUB-W is also very nice. Three BEC’s and Servo voltage (5, 6, 7.2V) that’s selectable.
http://www.mateksys.com/?portfolio=fchub-w

When i build another copter this will be what I use.

[RCExplorer – David]

The F411-WING looks really nice! http://www.mateksys.com/?portfolio=f411-wing
Unfortunately, it won’t fit in the baby tricopter. It would have been freaking perfect. One board only with PDB and what looks like a good BEC.

[jihlein]

“I’m leaning towards the Matek at the moment.”

Well with one small change to the gyro driver, the Matek405Ctr target I have dRonin will work on both the Ctr (MPU6000) and Std (ICM20602) versions.

One thing to note is that to use SPort telemetry on the Matek boards, you will need to either an use an external inverter or use the non-inverted SPort hack on the receiver.

So if anyone has a Matek405Std they want to test with, I can have dRonin firmware put together quickly.

[Kevin_Erik]

@David

You have to change the hole placement around (24 * 24mm) but the board itself could fit. (41 * 28mm) From what i’ve read the RCE Race-F3 has 30.5 * 30.5mm hole spacing and is 36 * 36 in all.

It would be possible to model an adaptor and print it out of TPU and thus avoid the need to drill the carbon plate.

[RCExplorer – David]

Awesome @jihlein!
Stupid that they don’t have an extra inverter on there for the telemetry :/
Also something you mentioned earlier. The 405-STD does not have an internal 5V regulator. It needs to be powered with 5V and we really want to run the servos on 6V. There are no specs on the voltage input range on the 5V but it’s using the max chip for OSD and that thing gets smoking hot even at 5V.

The 405-STD together with the FIXED WING PDB FCHUB-W http://www.mateksys.com/?portfolio=fchub-w could be a pretty nice solution though. 4 different BEC’s. 3.3V for compass/GPS, 5V for the board and such, selectable 5/6/7.2V with good current capacity and 10V for VTX and such. Would be pretty neat. But I won’t get my hopes up. It might be too pricey.

[Kevin_Erik]

Once we have the F405-STD & Wing PDB FCHUB hardware viability confirmed, i could aquire the “basic” hardware and bench test it. Afterwhich I can aquire the frame and build it proper.

Note: I’ve the PDB on order as its just too awesome not to have it for the Tri-baby. Found one for €18 via Amazon.on ($15 on Banggood)

[jihlein]

I took my existing dRonin Matek405Ctr target and modified it to work with both the Matek405Ctr and Matek405Std. The target was also renamed to simply Matek405.

The only changes were in the gyro handling and the addition of two new gyro setup parameters. It works on the Matek405Ctr, when someone gets a Matek405Std, I’ll create an installer package so it can be tested on the new board.

Since I have to re-wire my BiCopter, I may put the Matek405Ctr in it…….

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