Onboard displays

Pun fully intended.

Huge step today, got my 3.2" TFT up and running and displaying data streamed from VESC! Piccies:



First piccie is a closeup of the display, second you can see one of the motors spinning in the upper-left. Third piccie is the board it’ll get mounted to - it’ll be inset in the front riser, right in front of the footpad.

DougM

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Looks super sick man!!

I also really like you custom drop deck- this is going to be one he’ll of a board

can you put a video ? cant seem to figure out how you’d turn .

It’s on skate trucks. Leaning=Turning

Correct, they are Revenges up front and Caliber’s in the back. Caliber’s are great because it’s easy to mount a motor to them for those of us who don’t weld.

Thanks CMatson, I’m trying to build the ultimate carving machine. I’m going to create a blog somewhere with all the build details - will post linkies.

DougM

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Good work. Are you streaming data back over UART ?

Yes, after a little initial drama it turned out to be pretty easy. I’m using RollingGecko’s VESCUart to pull the data down as well as control the motor.

The only thing I’m not able to do yet is get Fault information from VESC.

DougM

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THIS IS VERY COOL BROTHER! having this info is nice. should display wattage in real time.

Yeah, seems to be really sweet :smiley: How does the VESC know how fast you’re spinning though? I would think that that requires a sensored setup. I’ve been meaning to make a speedometer for my build using an arduino, external battery, a magnet attached to the wheel and a magnetic switch sensor. Im still waiting for my VESC and don’t know nearly enough about it! could you perhaps explain how you made the speedometer?

VESC returns the current RPM of the motor so then it’s just a matter of maths to convert that to MPH. The number I used was an approximation for display purposes. I’ll do it the easy way, crank the board up to full speed, record the RPM, then use the GPS on my phone to get my current speed and divide RPM by MP/H to get a conversion factor and use that in the firmware.

DougM

I’ve been reading up on vedders VESC code. I’m interested in how you pull the data to create a tachometer, as that is something I’m actively working on.

Configure your VESC for UART, wire it up and run RollingGecko’s VESCUart sample code - it will demonstrate how to set the current for the motor and how to retrieve state data.

If you get stuck let me know,

DougM

will do when I get a chance (schools crazy right now). What wheels are you using? those look alot like the good year tires I have and have no way of using.

They are 4" wheelchair casters from a place called FrogLegs. (froglegsinc.com)

The upside is they use the same bearings as skate wheels and are the same width so bolt right on. The downside is they are heavy and pretty spendy.

Are your goodyear tires pneumatic? These are solid rubber.

DougM

You need a set of pneumatics.

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I do! but for a lot of reasons I’m limited to 4" tires. If anyone can source 4" x 1" (or 1.25") pneumatics please let me know.

Also, finally got a break in the weather, so took the above board for its inaugural run. It is fast but not as stable as I was expecting. I’m beginning to think that for an “ultimate carving board” standard skate trucks are not going to do it. I’m going to have to start thinking about a suspension similar to BajaBoards but with much less travel.

Thanks,

DougM

My good year tires are all rubber. I have been told they will suck for range, but I can use a larger battery to make up for it. I just want a smooth ride, and that I don’t have right now with then enertion wheels.

Another reason to think about a different suspension. You can’t see it in the pictures, but my wood deck is floating about a half inch above the aluminum frame, suspended by rubber grommets. this allows the flex in the wood and the squishyness of the grommets to take up small vibrations, but the frame itself gets rattled pretty harshly.

DougM

hi @DougM I want to build a display (wired), but I know very little Arduino programming. Would it be possible to share your Arduino code? thanks Leo

Yes, there’s been a lot of demand for more information, so I’ll start posting details here.

Starting with this:

Order the display and the Zif connector:

Order the PCB here: https://oshpark.com/shared_projects/lZdlzNWj

You’ll also need to order a Teensy 3.2 - you can get them from OshPark when you order the PCB.

Next I’ll post a BOM.

If you want to just drive the display and don’t want any of the other stuff google “adafruit ili9341”

DougM

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