Servers by jDrones

Kakute F4 carrier board for Raspberry Pi

(Stephen) #1

As part of a larger project to create tiny indoor rovers, I’ve designed a Raspberry Pi HAT to interface with a Kakute F4 (non AIO version).

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It contains:

  • JST-GH connectors for GPS and RC
  • 4 motor outputs
  • UART telemetry connection between the Kakute and Pi
  • DC Jack for powersupply for both Kakute and Pi
  • Full 2.5A power supply for Pi
  • Cutout for Pi camera cable
  • Current sensing
  • Managed power on/off switch for the Pi, so the Pi will cleanly shut itself down before cutting power (no more corrupted SD cards!)

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The next stage is to tidy up all the wiring mods in V1 of the carrier board and clean up the design a little.

Raspberry Pi + Kakute F7
(Khancyr) #2

Excellent !

Ping me if you want to launch to produce a small batch of hat, I would be interested to buy one !

(rmackay9) #3

Looking cool! Great to hear that it’s for a rover!

(Stephen) #4

That’s the plan! If I get enough people interested it should make a small production batch practical to organise.

I’ve got it mounted to a Polulu 3Pi at the moment:

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Only issue so far is that since the Kakute doesn’t have any AUX ports, I can’t use the MOT_PWM_TYPE=3 for brushless DC motors. So I repurposed the Arduino on the 3Pi into a simple ESC.

It’d be cool if the AUX channels were just another SERVOn_FUNCTION so it could be mapped to any output port. It’d make it much easier for the smaller boards to be used in brushless motor rovers.

(Bernhard Klein) #5

uh, sounds good :slight_smile: - is this hat pcb available?
BTW: is it possible to share you schematic?

(Stephen) #6

The PCB is still a work in progress … I still need to fix up a few misplaced traces on it!

I’ve actually separated out the power module part for the Pi to make a standalone power/telemetry interface - I’ve posted some details of it on the Ardupilot Facebook group.

(Bernhard Klein) #7

nevertheless if pcb is ready for “ordering” - i’m interested in it

(Stephen) #8

I should be able to have something priced up by the end of the weekend… I think @khancyr was interested too.

(Tiziano Fiorenzani) #9

That would be perfect on my donkeycar for my ros videos! Keep us posted

(Kenny Trussell) #10

I am interested as well in a carrier board. I have several rover projects in mind. Currently I am using a Pixhawk 2.4.8 but need to research what would really work best. And I definitely need a coprocessor (R-Pi or other) to send some commands to the Auto Pilot over MAVLink and perform some separate functions. I have not researched the options, yet, but it seems I need to consider the Kakute.

(Stephen) #11

Ok, I’ve made a few changes to the board:

3D1
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3D2
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(Note the Servo output ports will be horizontal, rather than the vertical shown in the renderings

So it now has:

  • Separate power switches for the Kakute and Pi
  • Removal of current sensing (sensor was quite expensive)
  • I2C port breakout (from the JSH-GH port. The Kakute has it’s I2C port in an odd location, so the user will have to solder that themselves)
  • All ports face towards the USB-port side of the Pi
  • The Kakute’s USB port is accessible
  • Fixed up incorrect traces
  • Removed the ID EEPROM, as I’ve not quite worked out how to use it
  • Barrell Jack and XT60 ports replaced by solder pad, so the user can attach any power input plug they want.

Doing a small production run:

I can build these for roughly $40AUD per board. If I get more than 10 orders, I may be able to reduce the cost a bit (bulk discounts for parts, etc).

Postage isn’t included. It’ll likely be $20-30AUD depending on which country you live in.

If anyone wants a board, PM me with the quantity and country of delivery by 20/02/2019

(Stephen) #12

Just a reminder to anyone who wants a board - PM me by the 20th Feb so I know how many boards to build!

(Dave) #13

This would seem to address the PWM type problem if it makes it into Rover. Very nice looking board BTW!