Thursday, June 30, 2016

Eachine Blade 185 - vTX Video-TX Antenna Guard (EB185)

According to forum reports, several pilots have had some minor crashes that broke the 5.8ghz FPV video-Transmitter coax antenna connector off the quad ... sometimes, even damaging the main PCB. This is still pretty rough, but here is a proof-of-concept for a skid-plate idea I had.

Plastic is about 3.0-3.5mm thick. I find the existing screws are Metric and need to be longer.
There are 4 nylon spacers between plastic guard and quad ("to clear" gold coax soldered-on antenna connector).
Thread: M2.5 Thread (0.45mm pitch)
Length: 15mm  is what I use (depth is limited) 
Head: Usually something like Cap-Head Hex-2.0mm

  • Cut clear-plastic (from junk parts box) with Dremel to make more slim-line. Weight with nylon bolt is down to 13.1 grams. Simple and sturdy design of plastic and nylon do not interfere with antenna signals.
  • Added pieces of black foam servo-tape for padding between plastic guard plate and actual gold coax connector/PCB. It's easy to check tightness of antenna coax, and antenna still easy to swap out.
  • Protects connector and also prevents antenna from getting loose and twisting off into props.
  • Flight Test 7-1-2016 : Flies fine.

Wednesday, June 22, 2016

Cymatics: Science Vs. Music (Nigel Stanford)

Ok, I think any video a multiple Tesla-Coils deserves a post :) . I suppose it also touches on another interest of mine (home theater and htpc). But if I know you blog readers as a group, I think you will like it also.

Try to watch it in HD, Full Screen, and crank it up (or click here).

Monday, June 13, 2016

Eachine Blade 185 Recover Bootload boot Naze32 unbrick EB185

This happened soon after I had my EB185 hooked up to the laptop for the first time. I've been asked by a top forum contributor to document it. I had just installed CleanFlight and was running it for the first time ever. I was very unfamiliar with it (being my first exposure to Naze32 and CF) but quad seemed to be calibrated and working. The 3D model in CF was responding on the laptop screen as I moved the quad on desk.

I thought I needed to change the uart ports to be more like in EB185 manual. Well, you do ... but I mis-interpreted what they were talking about. After I inadvertently changed UART-1 Data away from MSP/115200 (by changing something else on that line) ... I could no longer Connect to quad. Basically, it appeared to be bricked.

As it turns out, the Naze32 is supposedly un-brickable. All you have to do is carefully short test-point Boot/Boot0 to 3.3volts, and plug-in it's power at the same time. The problem is that on the EB185, the Boot signal is not brought out to an easy to access test-point pad. So, in this case, you must use Pin#5 on STM32F chip itself.

Understanding what must be done, it seemed pretty hard to hold a probe on a single STM32F pin without it slipping and shorting to a nearby one ... not to mention holding a short while connecting power. Luckily, I ohmed-out Pin#5 and found it goes directly to the top solder-leg of the resistor right by it on the PCB.

Therefore, I carefully shorted these 2 points (marked in above pic in violet color) with a pair of sharp tweezers, while simultaneously connecting USB cable coming from laptop. Windows laptop detects Naze32 device in "Devices and Printers", but no sound from quad. Carefully lift and remove tweezers shorting the 2 points. At this point you should be done. It should connect now or the next time you reset the power (or re-connect USB).

I started CleanFlight and Flashed to: 1.12.1 NAZE 2016-4-10 (Stable). Recalibrated and reprogrammed. Good as new and back on-track. Note to self : Never do that again! Hope this helps.