This last update about VBRAIN add ON. In the picture you can see the first prototype of VR Neuron (Down) near the VR Brain (UP) . As you can see te board have the same mechanical design of VR Brain . The board is very compact 6x4 cm VR Brain 7x4 VR Neuron. You can put VR Neuron above and VR Brain up , connect the board by serial port and the use VR Neuron to connect the World :)
Above the board there is PAD for connect by an Header a breadboard or directly thw wire for add yor specific applciation. On the PAD there are available a lot of input output port 27 GPIO , SPI , I2C , Serial port .
In the next days will be more update until official presentation 9 November 2012 at Makers Italy .
In the last six month i decide to implement a new revolutionary design that could be usefull for add a lot on new functionality to our drones.
In the past we only work on micro controller : AVR , SAM3X, STM32 , great platform the last STM32f4 is best micro controller for manage our drone : acro and stable flight , loiter , waypoint navigation ecc ecc. But if i want to put on it a o.s. i start to have a lot of problem : small memory footprint available , not enough ram slow speed processor. So a lot of proposal .... ChibiOS , Nuttx . But what is better and opensource of the worlds ? No doubt It's Linux :)
In my professional work i used a lot of micro controller and micro processor , but all ,too complex to be hackable as a STM32. Until i start to play with a great Italian product , the first that put an Android on a wearable PC .
I like a lot the micro inside it and decide to use that microprocessor for my next opensource design.
I'm happy to present the first design of VR Neuron . It will be official present the 10 November 2012 at the Makers Italy exibithion so who would see our great new design are welcome to meet us at Makers Italy in Milan.
These are preliminary technical info about VR Neuron :
- Freescale Imx Arm9 microprocessor.
- 64 Megabyte Ram
- Flash until 32 Gbyte Flash on SDIO bus
- 456 mhz clock
- DUAL BEC 5V Input
- 1 for CPU
- 1 for USB channel
- 1 Pal Video Output
- 2 Audio Channel Output
- 1 Input audio channel
- 26 GPIO (LCD BUS)
- 2 i2c bus
- 1 SPI MISO MOSI SCK
- 2 serial Port
- 1 USB Host 2.0 channel
- Only 6x5 cm half of Raspberry PI
The operating system that i choose for my development is ArchLinuxArm , the powerfull of this design is incredible , i play a lot with the kernel and add a lot of usb device : wifi dongle , 3G dongle , webcam and install a lot of application and test it : apache2 , mysql , mjp-streamer .
So on this platform is possible to do anything of application , it's available python , gcc , i ply with mavlink_proxy and it work fine ... i connect the VBRAIN serial port to VNeuron and by wifi connect mission planner to VBRAIN and see live the telemetry of my quadcopter online.
With the PAL output could be possibile to develop a great OSD application or with oudio you can implement a tele presence systems ... the limit will be only fantasy :)
So i'm very exited about this project and i hope that you like it and join us in development.
Follow the evolution of project here :
Best
Roberto Navoni
Comments
By the way, if you change all 0603 passives with 0402 and sot-23 components with sot-323, connectors with high density ones, you could make the board even smaller. Also I use to replace most of the 10uF tantalum caps with low ESR X7R ceramic ones. The price is better and the housings are smaller.
Nick
Hi Roberto,
If you use Altium Designer for PCB design, you could just use Diffpair Routing using the impedance rure according manufacturer's specifications ( http://fplreflib.findlay.co.uk/articles/37941%5CHiSpeedDesignTutori... )
Hope it would help.
Best regards
Nick
@Hugo,
we don't have a lot of space for put our wire on the Neuron , all the routing is doing manually by Diego a LaserLab guy. So during the design we used the PCB rules to check the lenght of wire , so we don't use the serpentine because doing an accurate routing. So in the next day we receive the PCB and mount it so we can check how good is our design ;)
@Ralph that's great , at the moment i'm testing mavproxy as web service on VR NEURON , it's work but it need a lot of resource , in my test i verify that a video streamer service for standard 640x480 cam need only 8 % of cpu . Instead actual revision of mavproxy need around 80 % of cpu ... i don't understand exactly the reason of this need of resource but i think because use python and it's only an interpreter not a jit compiler. or a c++ application , so i think that as prototype we can use python on VR Neuron without problem but then could be good use c++ for release our application.
So i'm testing the opportunity to compiling the VBRAIN code directly to VR Neuron and update the firmware on it directly on VR Neuron so i don't need a pc for upgrade my VBRAIN on the Fields :)
If you meet the length matching requirements (you'll find all the information you need from the DRAM vendors or Freescale), then great - it's hard to tell just from the renderings, but it's just surprising and rare not to see any serpentine traces on a DDR design.
I am conceiving building web service on Linux flight controller.
Yes, I did. I use my Ubuntu Notebook everyday.
Hi Hugo,
so yes we are working with rule check for verify the length matching during the design of board. But that's is our first design and prototype with this kind of technology and this is first prototype so any kind of suggestions are welcome. Do you have experience on this kind of pcb ? What's normally the maximum difference in lengh of wire that is good for this kind of design ? The board is very compact only 6.5x4.5 cm and the cpu is on top of ram , actually we using a 4 layer pcb with power plane and ground plane as for VBRAIN.
I hope that could be work fine ... until now we doing a lot of test on freescale SDK board.
What's your suggestions for improve SDRAM bus and USB bus ?
Best
Roberto
Does the DDR SDRAM work? It doesn't look like you have any length matching on your PCB layout (nor does the USB diffpair appear to be routed to control differential impedance)...
Hi Ralph ,
thanks i hope that in the next days all process for production of first prototype going well :)
So for the next week i can power up the board ....
The first prototype work well so i think that also this one could be work fine.
Now i'm working on kernel , so i can prepare it for the board. And don't lost time the day of presentation is near :)
How many people use linux in DIYDrones community ?
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