Hello!
I am Vagos, I am new to multi-rotors. I wanted to build my own quadcopter from scratch (Frame, software, radio) , but after finding that there is an abundance of information on ready-made designs I steered a bit away from my thought.
Well, I constructed a quadcopter and loaded multiwii (I pretty much followed this guide regarding the components and connections), but I run to some problems with the electronics. Although I know my way around with microcontrollers and sensors, all these power electronics are new to me (ESC, motors, etc).
The arduino gets stuck in the startup and cannot make the motors turn. The led keeps blinking slowly (which, if I am right, means the is a problem with the I2C connection) and the ESCs beep twice as they should be.
My setup is pretty basic:
* Arduino pro mini
* Wii motion plus (from ebay, probably clone)
* 4x Hobbyking 25-30amp SS speed controllers
* 4x L2215C-900 motors
* 4500mhA nanoTech battery.
(not using nunchunk or any other sensor etc, also no breakout board)
(didn't touch the code except the :
"#define MINTHROTTLE 1120" and
"#define QUADP"
as suggested by the guide above)
I skimmed through the code and my guess is that it gets stuck while trying to calibrate the Gyro (The documentation is a little poor regarding this error).
Another guess is that the cause of the problem are the ESCs. HobbyKing's guys keep telling that the above ESC is not good for multi-rotors, but the multiwii site claims that the SS series can update fast enough. I can't really say. I have no knowledge of ESCs.
On the other hand, while I keep the arduino plugged in with the USB, everything works fine: The startup takes a few seconds, and after that I can start the motors fine; and the multiwii GUI program displays the 3-axis gyroscope graph and Rx flawlessly.
I also tested each motor/ESC independently by connecting the ESC directly to throttle channel of the Rx. They all worked fine.
I could really use some help/advice. Since I have no previous experience, I am afraid the I might be missing something simple.
With all this plugging-unplugging and poking around, it seems that I burnt a couple of ESC already for no reason.
Thank you!
Arduino gets stuck on blinking
Re: Arduino gets stuck on blinking
You should state the MWC firmware version you are using too.
Even if the ESC's are not compatible, the blinking LED behavior does not seem to be related. And the Armed LED (if installed) should still work even if the ESC's do not respond. But since the MWC gets its power from one ESC, the model needs the ESC's BEC feature to be functional. A voltmeter will tell you if the BEC is working.
If it works correctly with USB port connected, but is goofy when USB is removed, then I suspect your problem involves the power connections to the Arduino and/or sensors.
(1) The Arduino pro mini has a DC-input pin labeled RAW. What is the voltage measured on it? Hint: It should be 5.0V (typical). This voltage is sourced by one ESC BEC (the other three BEC's are normally disconnected by insulating the red wire found in their respective servo plugs).
(2) If RAW voltage is OK then check the voltage on the Arduino pin labeled Vcc. It is the output of the internal VReg and should be >4.8V. A dramatically lower voltage is not a good thing.
The GUI's I2C error counter will tell you if you have sensor communication problems. So pay attention to this useful data field.
- Thomas
Another guess is that the cause of the problem are the ESCs. HobbyKing's guys keep telling that the above ESC is not good for multi-rotors, but the multiwii site claims that the SS series can update fast enough. I can't really say. I have no knowledge of ESCs.
Even if the ESC's are not compatible, the blinking LED behavior does not seem to be related. And the Armed LED (if installed) should still work even if the ESC's do not respond. But since the MWC gets its power from one ESC, the model needs the ESC's BEC feature to be functional. A voltmeter will tell you if the BEC is working.
On the other hand, while I keep the Arduino plugged in with the USB, everything works fine:
If it works correctly with USB port connected, but is goofy when USB is removed, then I suspect your problem involves the power connections to the Arduino and/or sensors.
(1) The Arduino pro mini has a DC-input pin labeled RAW. What is the voltage measured on it? Hint: It should be 5.0V (typical). This voltage is sourced by one ESC BEC (the other three BEC's are normally disconnected by insulating the red wire found in their respective servo plugs).
(2) If RAW voltage is OK then check the voltage on the Arduino pin labeled Vcc. It is the output of the internal VReg and should be >4.8V. A dramatically lower voltage is not a good thing.
The GUI's I2C error counter will tell you if you have sensor communication problems. So pay attention to this useful data field.
- Thomas
Re: Arduino gets stuck on blinking
Thank you for your answer Thomas!
If I get it correctly what MWC version is (multiwii version), I got the latest: 2.0
Well, the voltages on RAW and VCC were ok, but after playing around with the voltometer, I found out that there was a loose solder connection on the negative terminal of the power rail (The rail which is connected to the BEC and powers the receiver and arduino), making the arduino operate without being "grounded", thus causing this erratic behavior. So thank you for pointing me to the right direction.
After fixing the power rail, the behavior seems to have returned to normal. Unfortunately, I still can't fly cause, with all this hustle, one ESC malfunctioned and "shakes" the motor instead of turning it (checked the motor with another ESC, works fine).
One more question though, You recommend that the electronics should be connected to only one BEC. The bayrc guide I followed, showed that, in addition to the negative leads, the positive leads of all ESCs should also be connected together. Is that a problem? could it be that it caused my ESC to break? It is not a problem disconnecting them, since they all hook up to the power rail via jumper wires, but I am wandering which pattern I should follow.
Thanks again
If I get it correctly what MWC version is (multiwii version), I got the latest: 2.0
Well, the voltages on RAW and VCC were ok, but after playing around with the voltometer, I found out that there was a loose solder connection on the negative terminal of the power rail (The rail which is connected to the BEC and powers the receiver and arduino), making the arduino operate without being "grounded", thus causing this erratic behavior. So thank you for pointing me to the right direction.
After fixing the power rail, the behavior seems to have returned to normal. Unfortunately, I still can't fly cause, with all this hustle, one ESC malfunctioned and "shakes" the motor instead of turning it (checked the motor with another ESC, works fine).
One more question though, You recommend that the electronics should be connected to only one BEC. The bayrc guide I followed, showed that, in addition to the negative leads, the positive leads of all ESCs should also be connected together. Is that a problem? could it be that it caused my ESC to break? It is not a problem disconnecting them, since they all hook up to the power rail via jumper wires, but I am wandering which pattern I should follow.
Thanks again
Re: Arduino gets stuck on blinking
ONLY use 1 BEC.
I would recommend using a totally separate uBec that works via DC2DC Step down instead of the linear in the ESC.
It will save you trouble in the long run. Disconnect ALL the +ve wires on the ESCS and use a uBec, or use only one single BEC from the ESC.
I would recommend using a totally separate uBec that works via DC2DC Step down instead of the linear in the ESC.
It will save you trouble in the long run. Disconnect ALL the +ve wires on the ESCS and use a uBec, or use only one single BEC from the ESC.
Re: Arduino gets stuck on blinking
The bayrc guide I followed, showed that, in addition to the negative leads, the positive leads of all ESCs should also be connected together.
I recommend that you only power from one ESC's BEC and disable the other three BECs. Don't cut the wires, just slide out the red wire from each ESC's servo plug and insulate it.
ONLY use 1 BEC.
+1
Unfortunately, I still can't fly cause, with all this hustle, one ESC malfunctioned and "shakes" the motor instead of turning it (checked the motor with another ESC, works fine).
If you are using bullet connectors on the motor leads then try this: On the "bad" ESC, remove the three bullet connectors on the ESC *and* motor; Directly solder the heavy wires instead. Now does the ESC work?
Even if this does not help, avoid using bullet connectors on the ESC leads.
- Thomas