Quad.Net Quadrocopter for .NETMF
#81
Posted 02 February 2011 - 09:47 PM
#82
Posted 04 February 2011 - 02:07 PM
#83
Posted 04 February 2011 - 08:52 PM
#84
Posted 04 February 2011 - 08:55 PM
Are there any schematics how to connect the "Dataconcentrator"?
I've taken a deeper look at your framework, it's a good piece of code.
I've added some code to support my peripherals.
I just need an arduino for the Dataconcentrator.
Hey zerov,
I don't have any schematics (it's all just proto'd right now), but at a basic level you will just need to interface your arduino (or any other realtime mcu), and the netmf board over I2C. I used this logic level converter to get them talking: http://www.sparkfun.com/products/8745. It's not actually strictly necessary to use the level converter between the arduino and you netmf board as they are usually 5V tolerant, however since I put the gyro and accel on the same bus you will need the converter(they are 3v only). I will attempt to put together a diagram of how I have everything wired up this weekend.
-Luke
#85
Posted 04 February 2011 - 10:59 PM
#86
Posted 05 February 2011 - 12:56 PM
I see why you use the Arduino to get the radio data, but why the motors are connected there too? Haven't the Netduino and Domino/Panda native PWM pins? I wanted to use the PWM's on my FEZ.
...
What do you think?
Yeah you noticed that eh? I originally was going to use my arduino as the flight control board. It was just easier to relay motor command over I2C. I actually just finished rewiring the shield so that the pwm pins come from my fez panda directly. So you totally had the right idea there.
So now the razor. Ultimately creating code for interfacing with stuff like the razor is something we want to do, we're just not at that stage yet. Wasting 3ms on parsing the razor's ahrs code is really a waste though, and really from everything i've seen about multicopters so far 50Hz is not gonna be nearly fast enough. You could totally re-write the firmware to get spit out raw data across serial on a demand basis and if you need help i can provide it. My personal recommendation is to just ditch the razor imu for this instead http://www.sparkfun....products/10321.
As far as concetrating all this data on another arduino, I think that adds too much complexity. All I really want the arduino to be is a PPM to I2C converter for the radio. I think eventually I will swap out the teensy for something even smaller.
Cheers
#87
Posted 05 February 2011 - 06:59 PM
The Razor 9dof would do all this calculations:
Direction Cosine Matrix (DCM) based Attitude Heading Reference System (AHRS) with gyro drift correction based on accelerometer (gravity) vector and magnetometer (compass) vector.
I have binary messages over serial: [type:length in byte]
[DIYd:4][ID:1][roll:2[pitch:2][yaw:2][checksum:2] => 13byte
But how to request data on demand? just send a byte to the Razor and respond?
#88
Posted 06 February 2011 - 06:36 AM
But if I take such a 9dof stick, I must make all the calculations on the .netmf device.
The Razor 9dof would do all this calculations:
I have binary messages over serial: [type:length in byte]
[DIYd:4][ID:1][roll:2[pitch:2][yaw:2][checksum:2] => 13byte
But how to request data on demand? just send a byte to the Razor and respond?
Yeah i would just setup a polling loop to check for an incoming message, then provided the data. and honestly you are providing the data so frequently I dont see any value in doing checksum calculations either.
The reason I don't want to be doing calculations on an external board is it reduces accessibility to the code. Principally we want to be able to plug and play hardware, with all control logic being done on the .netmf device. To be honest if your not gonna use the .netmf device to do your control logic then why use it at all. The additional arduino is for convenience, eventually I would like to move to native solution for handling the radio ppm stuff.
#89
Posted 06 February 2011 - 07:35 PM
#90
Posted 06 February 2011 - 07:41 PM
A pull-down resistor on PWM output?Any ideas?
#91
Posted 06 February 2011 - 08:09 PM
A pull-down resistor on PWM output?
I'm not sure what that would do. The issue is that for the escs to boot they want to see a 0% signal (1000 us pulse, or whatever they have been calibrated for).
#92
Posted 06 February 2011 - 08:32 PM
A pull-down resistor pulls the output to ground - so, there will be 0% PWM output (logic low) during Netduino startup (when the pin is floating high). With the proper value (~2 kΩ was reported to be working fine), PWM output (logic high) will override the logic level set up by the pull-down resistor, so the ESC then gets the PWM waveform.I'm not sure what that would do. The issue is that for the escs to boot they want to see a 0% signal (1000 us pulse, or whatever they have been calibrated for).
#93
Posted 06 February 2011 - 09:35 PM
A pull-down resistor pulls the output to ground - so, there will be 0% PWM output (logic low) during Netduino startup (when the pin is floating high).
Your missing the point, 0% output is not logic low, 0% output is a pulse lasting 1000 microseconds every 20 milliseconds. Holding the pin low would not do anything.
#94
Posted 06 February 2011 - 09:40 PM
I see - sorry for my misunderstanding.Your missing the point, 0% output is not logic low, 0% output is a pulse lasting 1000 microseconds every 20 milliseconds. Holding the pin low would not do anything.
#95
Posted 06 February 2011 - 11:53 PM
I see - sorry for my misunderstanding.
No problem I didn't mean to be rude in my response. Actually thinking about it though it might be worth a try. I wasn't thinking about the fact that the pins will float during startup, I'm gonna try this anyways it might actually be a solution. Given not what I was thinking of, but I will report back if this works.
Cheers
#96
Posted 07 February 2011 - 06:29 AM
#97
Posted 11 February 2011 - 03:31 AM
#99
Posted 16 February 2011 - 08:16 AM
Do you know DIYDrones ?
These are our Arduino-based open source autopilot projects:
* ArduPilot, a low-cost autopilot system for planes.
* ArduCopter, a fully-autonomous quadcopter and heli UAV system.
This can help you...
--
Iliak
#100
Posted 18 February 2011 - 06:01 AM
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