Warning: Do not press on the headers of the UAV DevBoard
UAV DevBoard pilots:
Be careful not to press on the pin headers of the UAV DevBoard, especially the gyros.
It turns out that is exactly what I have been doing several times a week, for many weeks. I do a lot of programming and I found it convenient to leave my board right in my plane while I programmed it. My board is velcro mounted, so to keep it in place while I pull away the programming cable, I have been pressing against the Y axis gyro.
I discovered today that my Y axis gyro was not responding. I think I have made several flights without benefit of its signal.
A little heat on its pins got it working again. My theory is that there was a cold solder joint that opened under the strain of my pressing on the gyro. I contacted SparkFun, and they recommended that we should not press on any of the headers. This is the reason that they cited for why they trim the excess off the header pins before they solder the pins. They also said that they would take extra care to make sure the gyros are well soldered into the board.
In the process of losing the Y gyro signal, I learned that MatrixNav will provide adequate performance with only 2 gyros and 3 accelerometers. 3 gyros provides the best performance, but with only 2 gyros, the DCM algorithm managed to track well enough to keep the plane level and to return it smoothly to the launch point.
Also, in the process of trying the board on a helicopter, it was found that vibration will open any cold solder joints.
So, I have the following recommendations:
1. Do not press on the headers of the UAV DevBoard, especially the gyros.
2. If you have been pressing on the gyros while you remove the programming cable, run the roll-pitch-yaw demo to make sure all three gyros are still functioning.
3. If you find one of the gyros is not responding, or if the board has been subject to vibration, or if the gyro connections do not look like they have been heated enough, resolder the pins that connect the gyros to the board and rerun the demo to check it.
Best regards,
Bill Premerlani
Be careful not to press on the pin headers of the UAV DevBoard, especially the gyros.
It turns out that is exactly what I have been doing several times a week, for many weeks. I do a lot of programming and I found it convenient to leave my board right in my plane while I programmed it. My board is velcro mounted, so to keep it in place while I pull away the programming cable, I have been pressing against the Y axis gyro.
I discovered today that my Y axis gyro was not responding. I think I have made several flights without benefit of its signal.
A little heat on its pins got it working again. My theory is that there was a cold solder joint that opened under the strain of my pressing on the gyro. I contacted SparkFun, and they recommended that we should not press on any of the headers. This is the reason that they cited for why they trim the excess off the header pins before they solder the pins. They also said that they would take extra care to make sure the gyros are well soldered into the board.
In the process of losing the Y gyro signal, I learned that MatrixNav will provide adequate performance with only 2 gyros and 3 accelerometers. 3 gyros provides the best performance, but with only 2 gyros, the DCM algorithm managed to track well enough to keep the plane level and to return it smoothly to the launch point.
Also, in the process of trying the board on a helicopter, it was found that vibration will open any cold solder joints.
So, I have the following recommendations:
1. Do not press on the headers of the UAV DevBoard, especially the gyros.
2. If you have been pressing on the gyros while you remove the programming cable, run the roll-pitch-yaw demo to make sure all three gyros are still functioning.
3. If you find one of the gyros is not responding, or if the board has been subject to vibration, or if the gyro connections do not look like they have been heated enough, resolder the pins that connect the gyros to the board and rerun the demo to check it.
Best regards,
Bill Premerlani
Replies to This Discussion
-
Permalink Reply by Peter Meister on -
Thanks bill for the recommendations, I have done this once or twice myself. Will not do it again.... :)
-
Permalink Reply by Gil on -
Hi Bill, i´ve got one question about the programmer pinout socket of the redboard, can you tell me which pin is what in order that i could make an adapter/extender so it can be programmed from the outside of the plane fuselage using my Pickit 2 ?
I want to give it a try with this programmer but first i need to compare the pinout references and make the adapter.
thanks in advance
G
-
Permalink Reply by William Premerlani on -
Gil,
Looking at the connector from its edge of the board, going from left to right, the pins are:
VPP (MCLR)
VCC
GND
PGD
PGC
PGM (not connected)
You can double check that by powering up the board and measuring the voltages on the pins without anything else connected to the board. You will see supply power on pins MCLR and VCC. You will see zero volts on GND, PGD, and PGC. PGM will be open circuit.
Best regards,
Bill
-
Permalink Reply by Gil on
-
Hi Bill, thanks ...i´ll check this out and post the results about the compatibility of the PicKit2 programmer.
best regards
G
-
Permalink Reply by chris eldred on -
Gil
how did you get on with the pickit2, I have had varying results, the "pitch roll yaw demo" test program works ok but matrixpilot always comes up with "BUILD FAILED"
regards
chris
-
Permalink Reply by Matthew M on -
Hey guys here are where my Pickit2 posts start in the other UAVDEV BOARD (UDB) thread...
http://www.diydrones.com/forum/topics/discussion-forum-for?xg_sourc...
I just started with the board and a Picktit2, there are a few bumps to getting set up but it's well documented here and on the Google group (http://groups.google.com/group/uavdevboard) .
-
Permalink Reply by chris eldred on
-
reloaded microchip software for the "nth" time, now it works
chris
-
Permalink Reply by XING on -
Hi Bill,
I have currently bought a UAV v2 Development Platform for controlling a quadrotor. Can I know how can I get the gyros and accelerometer readings out from the board? I need to know the current orientation information of my quadrotor before I can adjust the speed of the motors. It will be the best if you could provide me with the coding on how to retrieve the orientation information (angles and angular rates) from the board.
Thank you and regards,
Xing
-
Permalink Reply by Pete Hollands on -
Hi Xing,
It is my understanding that you will need a Magnetometer in order to be able to control a quadrotor with the UAV DevBoard. Fortunately that piece of work is ongoing right now.
Also, you will probably want gyros that are less sensitive to Gyros than those that are on the standard Red Board. There has been quite a bit of discussion about all this both on DIY Drones.com and the uavdevboard discussion list. I think you should search through those discussions for "helicopter" and "quadrocopter".
When you say that you need to know the current orientation of the the quadrotor in order to adjust the speed of the motors, are you really saying "What part of the firmware should I modify", or do you mean that you would like that information (orientation) to be sent back to a PC ? I guess that initially you need to display the information on a PC to check that vibration is not upsetting the gyros. In that case you should follow the instructions on the Wiki at this location.
Once you have the serial connection working, I can point you towards some code that will show you how to work out the orientation of the quadrotor from the values of the Direction Cosine Matrix (DCM).
Pete
-
Permalink Reply by XING on
-
Hi Pete,
Thank you very much to your fast response. Yes, I'm really meant to get those information to be sent back to PC. Can I know besides the Breakout Board for FT232RL USB to Serial as shown in the link that you've given, do I have other ways to retrieve the information to PC?
Thank you and regards,
Xing
-
Permalink Reply by Pete Hollands on
-
Well the main other way is to use an Xbee transmitter and receiver, which is also described in the Wiki.
-
Permalink Reply by XING on
-
Hi Pete,
Thanks again for the your fast response, really appreciate it.
I've temporary got a USB to UART converter (UC00A from Cytron) while waiting for my XBee module to arrive. It's my first time using UART module to get information. Can you assist me with some idea or possibly source code on how to work out the orientation of quadrotor from DCM using thie serial connection?
Thank you and regards,
Xing
Top Content
Groups
-
ArduCopter User Group
477 members
-
ArduPlane User Group
299 members
-
ArduCopter (traditional …
77 members
-
ArduPilot (legacy) User …
77 members
-
Moderators
50 members
-
ROS User Group
31 members
-
Team Prometheus
11 members
© 2012 Created by Chris Anderson.
