Now we’re starting to get somewhere.
The brushless motor gimbal arrived yesterday, and I spent last night assembling it. Assembly notes (there are no instructions)
~ You need TINY allen keys in order to set the grub screws in. I don’t actually have my grub screws done up which is why I think my gimbal spazzes out and doesn’t quite correct sometimes (the motor axles are spinning as they’re not being held tight by the grub screws). I need to pick some up next time I hit up the hardware store.
~ You need to solder the wires on the brushless motors. It doesn’t matter where they go as if you get it wrong, its easy to reverse from within the GUI provided.
~ Use locktite if you have any on the screws – I can see these vibrating loose
~ Once assembled, ensure that the gimbal moves freely, then make sure it is balanced. If both axis are balanced, the gimbal will be most responsive, as the motors will have little static load.
~ The gimbal comes with a tidy spot to house the Martinez board, which is nice.
I actually had a lot of trouble in getting this right. I think I fried my IMU when I soldered it (I accidentally had my iron on HIGH and the IMU got too hot to touch at one point) so last night it was very glitchy. I also had the accelerometer accidentally mounted upside down on the unit.. haha. Check the GUI to see, the lines when at rest should both be near the middle of the chart. If they are up the top ( like in my previous vid) the IMU is upside down.
I had also negated to include the ‘int’ cable from the IMU to the Martinez board. Without this it also seems to glitch out a bit. Adding this gives us 5/5 usage for all the pins on the Martinez board IMU side.
Then a show stopper. Everything is all hooked up, but nothing works, just dead. I hooked up the Arduino IDE to it and opened up the serial port. The Martinez operates on 115000 baud so select this to see the output. I had the following message, thousands of times over:
“Motion detected during Gyro calibration. Starting over!”
Looks like my poor fried little IMU is tripping out.
This segment seems to get triggered if the gyro detects too much of a disturbance during its boot up phase. I added:
Serial.println(gyroX);
Above it to see and then re-uploaded the sketch. Sure enough there she goes, all over the shop.
There is a hard coded value, TOL, which must stand for ‘tolerance’ within ‘orientationRoutines.h’. So I added 100 to this, and now we pass calibration and boot up.
#define TOL 196
Strangely enough, the IMU only seems to glitch out when its been on for an hour or so. Tonight, its working pretty well.
Next step – all my settings for the unit were wacked out. I couldn’t find anywhere how many poles the brushless motors had… so I guessed a lot. Then I looked up some things. Then I concluded that they have 14. The side of the motor says ’15’ though, and this seems to give pretty good results so here it stays. I’ve left all the other settings within the GUI as default:
Rctimer gimbal Martinez settings
Video:
Step 3 will be to add some kind of frame/handle, mount the gopro and go out to film something!