bits and pieces

I could not really find an problem with the wiring nor the bullet connectors. To exclude the later, i re-soldered the bullet connectors with proper solder i.e. solder containing lead. To test the system, i tied down the quad to an heavy weight and let it hover (throttle at 50%) for about hour. Then another hour of hover with the throttle at 60%. The difference is that the later draws about 25A where the former draws about 7-8A.

Btw. wear protection glasses in case of an prop failure.
Anyway, the quad withstand the test without an hiccup. Time for some flying!

As you can see, flying in windy and gusty conditions is not a walk in the park. Constantly correcting for the wind to stay put on a spot is really difficult with this FC. The GoPro acts as sail on the quad. On the other hand, the NAZA handled it rather well judging from the video. Note that is without an gimbal!

Today i exchanged the two camera’s for the GoPro HD 2. Took it for a spin inside which went well, without fiddling with gain settings.

Nice, time to take it outside. The maiden flight with the GoPro was an disaster.

Out of the blue, the FC decided to roll hard. Could level the quad for a moment, took a breath and again the dammed thing decided to roll over again! But now i had no authority and the quad dove into the pavement.

Achilles heel of the boom…

I check both left side ESC, bullet connectors for cold solder joints but all checkout okay. Why on earth would the FC decided to roll? Bug?

The build with Turnigy ESC was troublesome as the flight controller would (most of the time) reset the ESC on power up. It is an drag to calibrate the ESC. So i purchased two DJI Naza flame wheel F450 kits (frame+ESC+motors).

The frame itself is very durable (see this vid), but heavy compared to a MK frame. As the JRPROPO does not have fail-safe, switch to the Turnigy9x with the Frsky system. It is disappointing that the Naza does not support PPM. At first the NAZA would not arm when executing the Combination Stick Command (CSC).

This was due to the inverted elevation in the configuration software. After this hurdle, it was fiddling with the gains. After 30 lipo’s, still fiddling…  it is hard to find an optimum for both manual mode and atti mode.

Not quite stable yet, but i more confident that it won’t flyaway. Time to put the GoPro2 on it.

Yet another FC, this time an proper processor, open-soure/hardware and an descent price tag of 60 euro including p&p. You can obtain one from AbuseMarK.com.
This FC, named AfroFlight32, is actually an rant build by TimeCop. And is similair to the FreeFlight FC (RCG forum) without e.g. the odd orientation. It was delivered in five days from Japan! HobbyKing, i am still waiting for the Frsky stuff!

Specs:

• 36x36mm CopterControl-sized 9DOF flying thing
• STM32F103C8T6 32-bit ARM Cortex M3, 72MHz, 64K flash, 20K SRAM
• ADXL345 Accel
• MPU3050 Gyro
• BMP085 Pressure
• HMC5883L Mag
• CP2102 USB Serial bridge
• 6 + 8 PWM I/O
• 2 status LEDs
• 5V Buzzer connector
• Battery voltage monitoring
• PWM/PPM RX input
• software is ported from the MultiWii

The actual board is green.
 

The MPU-6050EVB with INV-ArmBoard is okay to get you started. It has one drawback, communication is done with I2C. As most of the sensors used are on SPI,  I so ordered the ArduIMU+ V3. As P&P is expensive nowadays, i added the ArduPilot Minim OSD and optical flow sensor to the order.

The Minim OSD is MAVlink protocol compatible. It grabs some telemetry data from the MAVlink stream and adds it on the camera signal. The configuration software and Minim OSD description can be found here.

The optical sensor is used to level an vehicle by looking at the horizon. This does not work (obviously) at dimmed conditions. More information an be found here.

Tip: if you use a lot of SVN/Git sources and use an Mac, try SourceTree from Atlassian.

I have two modified Turnigy 9x transmitters, both with the Smatieparts programming and EL backlight. One has the er9x firmware, the other has the th9x firmware. I did not actively watch Gruvin’s progress on the custom main board development for the Turnigy/iMax/Eurgle/etc 9X RC Radio. At the beginning of this month i saw that project was finalized and one could order these boards. Note that one cannot order fully assembled board. Now you can order fully assembled boards!

Below is the RC modeller’s wet dream for €125 (US$158).

Order the FrSky DHT 8 channels with telemetry transmitter and three FrSky D8R-II 8 channels receiver with telemetry to upgrade the Turnigy 9x Tx/Rx. Cost of this about 100 USD without customs.

All these stuff will replace mine JRPROPO Rx/Tx stuff.

Drum roll, the ArduPilot Mega 2 from DIYdrones has landed on mine doorstep! Below an picture of this flight controller with an USB HASP dongle above it for size indication, it is really small !

Bye bye DJI NAZA you are obsolete

I love these open-source & open-hardware projects and their communities.

Finally made an Quad-X  copter with the DJI Naza FC.
Parts:

• FC: DJI Naza firmware v1.04 bought from DIYdrones UK
• ESC: Turnigy Plush 30A (ATmega processor)
• Arms: MK Koax Alu rigger red
• BL motors: KDA 20-22L
• Props: 11×4.7
• center plate: Flyduino Quadrocopter
• Battery: Turnigy Nano tech 2.2Ah 3S 50C
• TxRx: JR Propo DSX7 with RD731

The verdict after two flights:

1. The arming/disarming procedure is okay.
2. The cut-off types (read stop the motors), immediately and intelligent, suck big time. When the throttle goes down 10%, the cut-off type is activated. This works way differently than all the other FC i have flown. There is an discrepancy between what the manual states and what the FC actually does.
3. In attitude mode there is very little authority (very slow response on changes) from the sticks.
4. Altitude is variable, i rather have an switch to hold the altitude.
5. Hovering and maintaining altitude works beautiful on the spot. However, moving forwards and the quad loses height!?
6. Changing mode in flight (MAN <=> ATT) and the quad jumps/falls ! This due to the 50% throttle at which the quad hovers on the spot.

I like the manual mode over the attitude (hover) mode. With the help of expo and dual rate, the quad will behave similar like the other quads. But this jumping thingy is very scary and dangerous. I was not aware of this, the quad came down fast and slammed into mine leg. Lucky me, it cut only mine jeans.

Another issue i have is with the combo ESC / Tx+Rx and the configuration program ‘assistant’. This configuration works:

Channel #2 = ALE and Channel #3 = ELEV

These combo’s work:

1. E=REV & A=NORM with ALE=NORM & ELEV=NORM
2. E=NORM & A=REV with ALE=NORM & ELEV=NORM

Very, very strange… This is the first FC which does not play nice with the JR Propo. I will try the Turnigy 9x in due time.

People got badly hurt by the way the FC behaves, see this post at RCG. This quad is grounded till DJI changes and/or fixes the firmware.