New Guy Needs Help with MultiWii Flight Controller

[TheOrigNewGuy]

Hello,
I'm new to the hobby, and I'm very excited to get into it!! I'm building a tricopter for the first time and I need some help please. Components I'm using:

• Electrohub Tricopter Kit with Tough Tilt Servo - ES3154 Emax
• Hobby King F-20a flashed with SimonK. (I verified that all three ESCs work properly after flashing.)
• hexTronik DT750 Brushless Outrunner 750kv
• Turnigy 4S 20 - 30 C 3000mAh
• Ready to Fly Quad's MultiWii Pro 2 with uBlox 6M GPS W/Mounting backplane and compass with PCB Shield and the bluetooth kit. (Found here).
• Turnigy 9X transmitter and receiver.

I also posted on RCGroups asking for help, here.

Here is as far as I've gotten:

• The FC only powers up when connected to the computer via USB.
• When battery is connected and the FC is plugged in via USB the motors will spin according to my input on the throttle of the transmitter (i.e. it starts working properly).
• When connecting the battery without plugging the FC into the computer via USB the LEDs will be very faint and nothing will power on. I tried powering the GPS, bluetooth and tail servo off of two ESCs and the last ESC reserved for the FC only, but I still get the same dim LED's and the FC not working.
• GPS Does not work at all. (I've checked my wiring per the RTFQ's website. Maybe it is because I am in my house?).
• Bluetooth works properly (tested with phone).
• Tail servo moves but is very glitchy, moves back and forth uncontrollably.
• I think I still have to do some adjusting on my transmitter because I couldn't get my FC to ARM (when plugged into USB) until I manually programmed the FC to arm via a switch on the transmitter.

Thank you in advance for any help.

 

[makattack]

It's hard to diagnose this sort of problem, but did you solder the ESC/motor output pins yourself or did they come pre-soldered? Either way, if you have a magnifying glass, I would double check them or try switching the ESC with the BEC between all the different pins to see if it's a cold joint that's causing the problem. Also, maybe you can do a continuity test between the power and ground pins (all of them) with a meter that outputs no more than 5V. Be careful not to touch the signal pins when doing this.

The glitchy tail servo might be from RF interference... is the servo wire twisted? Do you have a ferrite ring you can wrap the wire around a few loops?

As for the GPS, I take it you're not getting a lock LED after a significant amount of time? If so, that's probably because you're inside... otherwise... not sure. Need more testing/information.

Good luck and hope you can sort it out!

 

[TheOrigNewGuy]

It's hard to diagnose this sort of problem, but did you solder the ESC/motor output pins yourself or did they come pre-soldered? Either way, if you have a magnifying glass, I would double check them or try switching the ESC with the BEC between all the different pins to see if it's a cold joint that's causing the problem. Also, maybe you can do a continuity test between the power and ground pins (all of them) with a meter that outputs no more than 5V. Be careful not to touch the signal pins when doing this.

The glitchy tail servo might be from RF interference... is the servo wire twisted? Do you have a ferrite ring you can wrap the wire around a few loops?

As for the GPS, I take it you're not getting a lock LED after a significant amount of time? If so, that's probably because you're inside... otherwise... not sure. Need more testing/information.

Good luck and hope you can sort it out!

Thank you for your help! With a multimeter, I measured all the ESCs. They all gave out 5V without any problems. I did solder the ESCs myself, so I removed all the ESCs and plugged each one in by itself, and the same problems keep reoccurring. Could the FC be faulty? I'm really bummed because I was looking forward to flying it this weekend.

 

[makattack]

Actually, what I'm suggesting is setting the multimeter to the continuity test (and doublechecking to make sure it only uses 5V or less) and testing the flight controller motor input power/ground pins to make sure they're soldered ok. It should beep/make a noise, and show a value on the meter.

Alternatively, you could try plugging one of those ESC's into each motor input to see if it changes the amount of power you're getting / the LED brightness.

You could also have the ESC powering the flight controller, then with your multimeter, go ahead and measure the output power on the RC side (the side that connects to your receiver) -- it should measure about 5V... then compare that with the case when it's powered by your USB...

You're basically trying to debug the hardware much as you would software... isolate the problem, identify and eliminate the variables that affect it, etc...

 

[TheOrigNewGuy]

Actually, what I'm suggesting is setting the multimeter to the continuity test (and doublechecking to make sure it only uses 5V or less) and testing the flight controller motor input power/ground pins to make sure they're soldered ok. It should beep/make a noise, and show a value on the meter.

Alternatively, you could try plugging one of those ESC's into each motor input to see if it changes the amount of power you're getting / the LED brightness.

You could also have the ESC powering the flight controller, then with your multimeter, go ahead and measure the output power on the RC side (the side that connects to your receiver) -- it should measure about 5V... then compare that with the case when it's powered by your USB...

You're basically trying to debug the hardware much as you would software... isolate the problem, identify and eliminate the variables that affect it, etc...

Ok, I give up on this thing. I've tried everything. Thank you very much for your time and help makattack.

 

[makattack]

Sorry to hear... you should describe the problem to Paul and send it back to him for a refund or replacement. On that note, I might recommend a newer type of flight controller... If you're set on getting GPS functionality, I think you may want to look at either a TauLabs board or APM/Pixhawk.

 

[TheOrigNewGuy]

Sorry to hear... you should describe the problem to Paul and send it back to him for a refund or replacement. On that note, I might recommend a newer type of flight controller... If you're set on getting GPS functionality, I think you may want to look at either a TauLabs board or APM/Pixhawk.

I've heard of APM, but not TauLabs or Pixhawk. I will look into those.

Mine friend had a spare CC3D laying around that he let me use, so for now I put it on my tricopter and I finally have the thing running! I'm guessing I need to do some tweaking though because when I tried to fly it it just ended up flipping over. I will do more research on this now.