Status: nineteen grams

Rev 3 arrived from Oshpark, and most of the hardware issues are fixed.

I've had so many comments on how to cut some of the weight- thank you!

From your suggestions, I've removed the PCB under the antenna, saving a couple of grams. Great idea!

I've chosen to keep the battery charging on the PCB. In the final piece, there will be a lot of fast changes and I hate swapping batteries while *doing*other*stuff*. Those tiny battery connectors are a total PITA. A really good idea, but no :)

PCB changes in this rev:

ESP footprint fix
New micro USB part with legs that grab into the PCB (thanks to @Voja Antonic for this hint)
Larger diode that I can see the cathode end (picked one that is way too large, it's in the top left next to label C1 :)
Battery off switch, which is the wrong part
PCB cutout under antenna

Net: 19.1 grams with everything on the board is exactly 3 grams too heavy. I think this is OK, the programming header won't need to be there in the final (-1.2 grams) and there will likely be some other reduction.

Changes for next rev:

New ESP (ESP-M2 or ESP8285)
Pogo pin fixture
Slide switch for battery OFF
Capacitor footprints should be the same (nitpicking)
Silk screen on back for 3rd motor placement
0.8 mm PCB from @oshpark

Immediate next steps are getting the communications going. I'm following this most excellent tutorial here.

Discussions

Paul Andrews wrote 12/06/2017 at 17:19

@davedarko the PSF-B85 (and the A-85) have the antenna on-board. I have made my own board from scratch using an ESP8285. I used a chip antenna and was careful about the trace design and it works fine. If I look at some of the commercial boards, they don't seem so careful, but they still work fine!

Are you sure? yes | no

Sophi Kravitz wrote 12/06/2017 at 17:42

I think I will use a module rather than laying out my own antenna. 😀

Are you sure? yes | no

deʃhipu wrote 12/04/2017 at 17:38

I still can't understand why you are using the huge and heavy ESP-12 module, when there are modules like the ESP-03 which are much lighter and smaller.

Are you sure? yes | no

Sophi Kravitz wrote 12/04/2017 at 20:34

I'll probably change to the ESP8285 on the next rev

Are you sure? yes | no

davedarko wrote 12/04/2017 at 21:11

[Left for readibility but based on brainfart]

I like that idea, but there's less support out there

Are you sure? yes | no

Paul Andrews wrote 12/06/2017 at 01:33

Recommend this ESP8285 module https://www.itead.cc/wiki/PSF-B85

@davedarko Why do you say there is less support out there? It works just like an ESP8266

Are you sure? yes | no

davedarko wrote 12/06/2017 at 06:22

@Paul Andrews wuah, sorry I was confusing the ESP8285 with the ESP14 module that has an STM8 on it. Nevermind, sure ESP8285 makes sense, good luck with the antenna design!

Are you sure? yes | no

Sophi Kravitz wrote 12/04/2017 at 13:34

Thanks Dave! Someone on twitter recommended making a pogo pin fixture for programming. Swiss cheese...maybe, I think that might interfere with the aerodynamics (haha, as if a balloon could be described as aerodynamic)

Are you sure? yes | no

davedarko wrote 12/04/2017 at 13:55

hehe :) thought so too with the aerodynamics ... you never now, maybe it vibrates and whistles with too many holes :D pogo pin stuff sounds good too :)

Are you sure? yes | no

davedarko wrote 12/04/2017 at 06:42

there are locking header footprints, where every second pin is offset a bit. With that you can put in a header when needed and it wont fall out.

You could take a bigger drill to make it a bit more swiss cheese like / voronoi style.

Looking forward to see a blimp fly :)

Are you sure? yes | no

Sophi Kravitz wrote 12/06/2017 at 17:43

Me too, me too 😀 really wish there was a blimp emoji

Are you sure? yes | no

PCB on a diet

Making two ESPs talk. One step closer.

Discussions

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