Obviously the test was in a ideal condition where the propeller just loosens and falls off the Octo.
The test was done by removing first 1 propeller, then two propellers spinning in opposite and same direction.
Without 1 propeller the copter flew as it had all the propellers. There was no feeling of something wrong. It took off and landed easily.
Taking off two propellers spinning in the same direction (lower front left and lower back right) resulted in a copter that in take-off yawed a little. Once the I term build up, it was perfectly straight. It was a little unstable due to the fact that two arms were "stronger" than the others, but generally it was perfectly stable even with some wind.
Taking off two propellers spinning in same direction (lower front left and right) resulted in a copter trying to move forward with quite a pace. I took a little pitch back to keep it still, but the overall stability was amazing.....
X8 will not take the loss of two propellers on the same arm, that would result in a crash, unless the recent algorithm gets published and then implemented in ACM code. :)
The code is based on APM:Copter 3.1.2 but runs on VRBRAIN.
Propellers are 13x5 T-motors on the upper and Graupner 13x8 on the lower.
Motors are 3508-700KV with 10Ah 4S battery.
Total weight was about 3.0 Kg.
Thanks to VirtualRobotix.it for the frame and the electronics, and thanks to the APM:Copter dev team that allowed us to fork and use their code, that is progressing fastest than speed light!
It is with great pleasure that we are able to present the result of our latest work.
In the last 4 months we designed, built and tested 2 frames and 2 Gimbals.
This is just a preview of these new products, production will start in the next month and pre-orders are available through our freshly re-designed web site www.virtualrobotix.it
Black Ops Drone aka B.O.D.
A multipurpose drone specifically designed for gaming and simulated wars. It is a plastic 2 shell frame very resistant and light weight. It is splashproof and can mount a small FPV camera on front. It can be used with many different payloads and mounts 3508 motors with 13" propellers.
VR TIGER SHARK
A powerful, tough and yet simple frame built with only 3k twill carbon fiber and High grade Aluminum.
The frame is designed so that X4 or X8 configuration is possible without any other add-on.
It is extremely tough and resistant, and host propellers up to 14" or 15" .
Typical configuration is with 3510 or 3508 Motors with 13" props, but also 40mm. motors can be mounted with no problems. The arms can be shifted in 1,5cm. steps to allow bigger props (15").
VR SHOCKWAVE GIMBAL
A professional 3 axis Brushless Gimbal built with 3k twill carbon fiber that is able to carry 3Kg. of payload.
This is our masterpiece. It uses high quality Stainless steel bearings and it is integrated with adjustable height landing gear.
It weights about 600gr. and it offers super smooth camera compensation.
VR SHOCKWAVE HANDY
The same Shockwave Gimbal can be used on our hand-held system allowing camera operators and professional photographers to obtain perfect stable images. The hand held mount can be equipped with remote control for PAN, TILT, ROLL and ZOOM.
VR EASYSHOT GIMBAL
A 2 or 3 axis Gimbal designed to fit the most common and light to medium cameras such as:
Sony NEX xx
Canon M series
Sony Cybershot VX420 or similar
Totally built wi Alu and Carbon fiber it is extremely light and it is sold with an antivibration plate suitable for any frame. It's weight without mootrs is 280gr. and is perfectly able to carry 300-400gr. of payload.
I have also set up a small and rather incomplete "how to" to upload the firmware into the STM32F4 ARM Microcontroller
Man!, never had so much fun with the Auto mode! I am using a UBlox GPS on a Hexa frame with 10x4.5 APC props.
The main difference between our code and the original Arducopter one is that we drive our main stabilization loop at 400Hz (instead of 100Hz) and get samples from the Gyro and Accel at 1000Hz (instead of 100Hz) with only 10% CPU time used.
The filter of the MPU6000 is set to 98Hz, although the Alt_Hold with the accelerometers worked very well.
Some perf mon :
VRBRAIN @ 2500Hz-400Hz
Function: cpu avg(ms) max(ms) Hz
fast_loop 10.31 0.257 0.325 400.0
fifty_hz 0.20 0.040 0.093 50.0
gcs_check 0.16 0.004 0.118 350.0
update_GPS 0.07 0.014 0.105 50.0
medium_loop 0.04 0.007 0.029 50.0
super_slow 0.02 0.189 0.277 1.0
slow_loop 0.01 0.012 0.032 10.0
free CPU: 89.17 8922
Here is the picture of the Waipoint path, as you can see I am not good in drawing, but the path was followed very well.
One thing that impressed me was the alitude, in all the auto mission only 1 meter between max and min.
The new altitude hold with use of accels is doing a great job also in autoland and auto-approach.
To all the AC team a big thanks for the huge work!
Hello Everyone, we all know our GPS board (the one that comes with the APM1) has no battery to backup data.
This has the disadvantage to make the GPS not very precise in the first minutes after power up and that every startup is a cold startup (at least one minute to get a 3D fix).
This is because the GPS needs find the satellites without a previous almanac (that is information on position of the satellites visible in that location at a specific time).
As you understand almanac is VERY important. Also considrer that the almanac is sent by every satellite and requires 12.5 minutes to transmit (or so).
"Finally, the almanac allows a single-frequency receiver to correct for ionospheric error by using a global ionospheric model. The corrections are not as accurate as augmentation systems like WAAS or dual-frequency receivers. However, it is often better than no correction, since ionospheric error is the largest error source for a single-frequency GPS receiver. Each satellite transmits not only its own ephemeris, but transmits an almanac for all satellites"
Of course this is not sufficient to have a perfect position: sky visibility, surrounding objects and number of satellites are the key factors.
This is why after a FIX (fixed blue led) number of satellites is very low (5 to 8) and this get higher (10 or 12) after some time of flying.
So, because of this, I decided to bring up an old hack made by Dcaspi, an old friend who worked also on the former Ardurpirates code.
The hack requires some soldering skills, so I suggest you to do it only if you are confident with it.
Beware if you fry the board or GPS unit, I cannot (nor Dcaspi) be responsible for it...
If you use the DIYDrones MediaTek? GPS, you're probably aware of the fact that, on each activation, it make take a very long time to get proper satellite lock. The reason is that it always starts from scratch; it is not aware of it approximate geographic location, not of the time.
The reason for this is lack of backup battery. Data is completely erased once you disconnect the main battery.
The GPS module itself has a backup battery input. Here we show how to connect an external battery to that input.
What You Need
You will need a a battery holder and a small, 3V, coin-shaped lithium battery. These can be purchased at any DIY electronics store.
I also used a piece of perforated prototyping board, but this is for convenience and not a must.
How It's Done
Below, you can see the GPS module board layout. Cut one trace as shown, and connect the two leads from the battery holder to the marked places.
Here is how the setup looks:
This is how it looks from below. Note the place where the trace is cut:
If you want to have a go at the MP32 from www.virtualrobotix.com, take advantage of the powerful 32bit ST ARM Cortex-M3 processor and would like to use your OILPAN with the great software the DIYDrones developres are developing, this is a small guide to get things started.
It will cover the biggest steps to configure the hardware and firmware.
Roberto has done a very good job, and since he lacks a bit in end user documentation (well that's tipical for almost every developer!!) I decided to give him a little help.
The code is ported form the 2.0.39 AC2 firmware and is is up-to-date with recent enhancemets. The planner will work just fine (at the time of writing 1.0.54)
The above is a video made by Roberto itself explaining setup for both the VRIMU and the OILPAN.
Before you can use the AC32 firmware you MUST solder two pin headers on the connectors shown below. You then need to short them in order to upload new firmware and fly! (you can use an old motherboard jumper plug to short the connector so you would be able to reuse your OILPAN on the old ATMEGA)
You also need a bind plug to put the MP32 in firmware upload mode(see later...). Or you can use one female-female cable like the ones posted above.
First download and install software and drivers
Download the latest VRIDE Framework. At the moment it is the 0.0.4.5.7 link here VRIDE.0.0.4.5.7 unzip it and place it in a folder like C:\MP32
You need to install drivers for your USB to serial adapter from here
You need to install DFU drivers for your MP32 board. You can find the drivers in the C:\MP32\drivers\mapleDrv\dfu\ folder of the VRIDE just downloaded.
Download the specifically modified firmware for the OILPAN from here OILPAN firmware. Unzip and overwrite the libraries folder in your C:\MP32 folder and the ACopter32 folder under the C:\MP32\Firmware\ folder
Installing the Mediatek GPS (DIYDrones)
At the time of writing only the Mediatek GPS from DIYDrones with firmware 1.6 is fully tested. The GPS needs to be attached directly on the MP32 board. To do this there are several ways. What I chose was to get a GPS cable adapter like the ones DIYDrones store sells and cut off one end that I solder directly on the board. You could also solder connector pins on both the MP32 and the GPS board and use a 4 wire cable.
This is a picture to explain what I did:
The 1st and last wire of the cable are not used, so you can cut them off. This is the schema on how to connect them:
Cable Wire # / Pin
GPS Adapter Circuit Board
JP19-6 (Ser4 Tx)
JP19-8 (Ser4 Rx)
This is where you will find the JPs on the board:
A picture shows were you can find the connectors:
Compiling and uploading the firmware
Configuring the VRIde
VRIDE is the "32bit version of Arduino". Is based on the LeafLabs? Maple IDE and uses a language much similar to the Arduino framework.
Once your hardware i ready and your drivers are finally set up you can start to open the vrobotix-ide.exe and in File-->Preferences choose the folder where you unzipped the VRIDE rar (eg. c:\MP32)
Then choose from the menu File-->sketchbook the Firmware-->Acopter32 sketch like in the Arduino framework.
This is your new firmware ready to be uploaded. But before we can continue we have to check and modify a few parameters in the code.
Modifying the code before the upload process
To let the compiler know you are using the OILPAN and not the VRIMU we need to make a few changes in the code. Nothing too difficult.Future developements will not require you to make all this modification, so keep up for the news! So follow these steps:
Locate the libraries folder in your C:\MP32 folder and open with a text editor like Notepad++ the following files:
AP_ADC\AP_ADC_ADS7844.cpp: be sure to comment out the #define VRIMU so the line would be //#define VRIMU like this:
If you have the old compass HMC5843 you have to open the file AP_Compass\AP_Compass_HMC5843.cpp and add a new line at the end of the defines: #define HMC5843 otherwise if you have the most recent mag, leave as it is.
Open the file AP_IMU\AP_IMU_Oilpan.cpp and comment out the //#define VRIMU and //#define VRMIMUIDG5000 line and add (if not present the line #define IMUOILPAN:
Now Plug the Bind Plug or one female-female jumper cable into the second input from the left of the MP32 (Called JP4_7, JP6_7 and corresponding to the 7th input of the old ATMega). Pins 1 and 3 must be connected toghether (The signal and ground pins)
This is used tu put your MP32 in firmware upload mode. When in this mode (and board powered) you will see a green led blinking on the MP32 board. This means you can start the upload process.
Plug the USB cable directly into the MP32 USB port. This is used as a power source and as a communication port.
Like the Arduino IDE, before uploading the firmware check that the code compiles correctly by clicking the Verify button. If code compiles, you can click on the Upload to board button.
Wait for the completed upload message in the VRIDE message window.
Setting up the firmware for first use
Once the code has been uploaded you will be able to interact with it using the USB-->serial adapter shown above, you have to connect the adapter to the Telemetry port on the OILPAN. To get into the CLI you will not have to switch the slider. This mode is disabled!
You need to use a Hyper Terminal to get to connect to the CLI the first time. This can be found in Windows XP in START-->All Programs-->Accessories-->Communications-->Hyper Terminal. For Windows7 and Vista you need to download the Hyper Terminal program from here:http://www.megaupload.com/?d=J31857IQ. This is the original Windows XP program.
So now that you have the USB-->Serial connected to the telemetry port and Hyper Terminal connected to the COM, power up the MP32 using for example the usb port on it. As soon as you connect you will see a message saying to press S to enter interactive mode. You have five seconds to press S after boot up. This will let you in the CLI mode. Use the the SETUP-->Reset to reset the parameters, configure your radio, level, calibrate ESC as you will do in old ATMEGA chip.
The ERASE function is not necessary.
Using the Planner to finish configuration
Once you have done first configuration, you will be able to connect to the MP32 using the AC2 planner found here
For all the rest you can use the the Arducopter Wiki which will guide you through the rest of the setup.
Frames supported by the code:
Quad X mode
Quad + mode
Hexa X mode
Hexa + mode
Features actually not supported by the code:
sonar is not implemented
camera mount stabilization is not working
All the rest should be working! This is still BETA so use at your own risk, and please report any issues to the Issues list in the Multipilot32 google code project.