AltimeterControlV3

[Micahfriesen]

This is my new project, a water rocket controller with 4 servo outputs, 200g 3axis accelerometer, barometer, sd card logging, optional 1.3" lcd full color screen, and 4 rgb lights. Pcbs and components are ordered, and it will need a good bit of programming, so it will be a while yet.

Here are some renders, board size is 2" tall by 1.5" wide

 

[Micahfriesen]

Pcbs arrived today, got the top side on one soldered.

 

[Micahfriesen]

There are switches and headers that go on there as well, but I didnt want to solder them on until I have all the surface mount components soldered.

 

[waltr]

Looking good and yes, get all the low & small parts on first.

I see a RESET button. I would be worried that G forces may close this. That would be bad to have the processor reset during boost.

Maybe a jumper to do reset.

 

[robopup]

Looking good and yes, get all the low & small parts on first.

I see a RESET button. I would be worried that G forces may close this. That would be bad to have the processor reset during boost.

Maybe a jumper to do reset.

Not a bad idea, but just a data point that I've never had a problem with my reset button below - max g's it has been through in flight is ~85. I use those low profile ones like the old Ardupilots used to have.


Lookin' good @Micahfriesen!

 

[Micahfriesen]

On the buttons. There will be a mounting case that has holes for the button which will prevent accidental triggering. One is a hardware reset, one is an arm button, and one is a clear button, so there are two buttons that can't be pushed.

 

[Micahfriesen]

Finished soldering



With optional screen

 

[waltr]

Not a bad idea, but just a data point that I've never had a problem with my reset button below - max g's it has been through in flight is ~85. I use those low profile ones like the old Ardupilots used to have.

Ok, if you know they will not trip then you're good.

 

[Micahfriesen]

Assembly is a bit difficult, as I have .019" pitch IC's, and about half 0603 and half 0402. You basically have to have a stencil. I placed all the components by hand, if I was going to do more I would use our pick and place.

 

[Micahfriesen]

Ok, if you know they will not trip then you're good.

I suspect that without support my buttons would trip, so support is definately a must.

 

[cerving]

Not a fan of 0.5mm pitch LGA's... I'm guessing that your accel chip is one. They are VERY difficult to hand-place... they were designed for pick and place machines with cameras, not humans.

 

[Micahfriesen]

Actually the cpu, screen connector, and accel are .5mm pitch. The cpu and accel are both qfn. If you can just get them placed fairly close they self center when you reflow them.

 

[Micahfriesen]

I have FreeRTOS running currently, next up is the SPI busses.

 

[Micahfriesen]

Its been a while since I last posted. I have the screen online with lvgl as a graphics driver, and the I can control the neopixel leds.

 

[Micahfriesen]

SD card works now.

 

[Micahfriesen]

200g accelerometer is working now, so that will be interesting.

 

[Micahfriesen]

All the hardware including the altimeter is working. Now all I have to do is piece it all together and we should be ready to launch

 

[Micahfriesen]

I think I am about ready to send it up in a rocket It will be on a proven rocket, just riding along for the first time for sure.

 

[Micahfriesen]

Well I launched it today
I didn't try for any sort of altitude record, just wanted it to work.