Update on ArduPilot Mega reset button issue
Jordi and the team have diagnosed the issue users are having with the reset button on the ArduPilot Mega IMU shield not working. Here's what we've found:
1) This is due to a conflict with the FTDI chip when the USB cable is plugged in. It is not an issue in the field, when the board is powered the normal way, with the ESC.
2) If this troubles you, we will be releasing instructions on how to modify the board (cutting a trace and soldering a wire jumper) to avoid it. The next batch of boards will have this fixed.
3) Needless to say, if your IMU shield is on the bottom and you're using the reset button on the APM board, there is no problem.
4) Remember that when you upload code to APM, Arduino automatically resets the board, so no manual reset is required. So you shouldn't have to use this button in normal operations anyway.
Replies to This Discussion
-
Permalink Reply by Chris Whiteford on -
Ahh good to know. Thanks for clearing this up. I had noticed it, but it wasn't high on my priority list to deal with.
I'll be curious to see the fix when its posted.
chris.
-
AdminPermalink Reply by Thomas J Coyle III on -
Chris,
The reset button works fine on my IMU Mega when I am using the IMU Mega USB port. I can reset the ArduPilot Mega anytime even when connected to the USB port.
Regards,
TCIII
-
Permalink Reply by Chris Whiteford on
-
Any update on this? I'd love to make the little fix so the button works reliably.
chris.
-
3D RoboticsPermalink Reply by Chris Anderson on -
Chris,
There are two solutions. The first is to replace a small capacitor on the board with a 1K resistor, as shown here:
The second is to attach an external reset switch. Solder the wires in place marked in green here:
-
Permalink Reply by Chris Whiteford on
-
Awesome. Thanks. I'll give the resistor change a go.
chris.
-
Permalink Reply by Uwe Gartmann on -
The reset switch on the IMU has the same electrical layout as the one on the MEGA board. I bridged the capacitor on the MEGA board with a thin wire. Now the reset work as mentioned.
-
Permalink Reply by Dr Mike Black on -
Great work around, but in fairness, i think over the last year i can count on one hand how many times i have used the reset switch.(AP)
Think i only used it to see if it did work :~)
Never had a reason to touch it otherwise...
mike.
-
Permalink Reply by John Ihlein on
-
I've got a problem connecting my APM board to the configurator, both the Arducopter and Aeroquad versions. I think it's related to this reset problem. In a nutshell, when trying to connect to the configurator, the APM is never released from the reset state and does not run. It works fine thru the Arduino serial monitor. I tried bypassing the capacitor on the APM board as described above. It connected during that debug session, but after putting it away and coming back to it a few hours later I'm back to not being bale to connect. I find it odd that the Oil Pan schematic specifies C16 as either 0.1 microfarads or 240 ohms??
Anybody else experience this, better yet anybody know what the solution might be?
John
-
3D RoboticsPermalink Reply by Chris Anderson on -
What rev is your board? ("foxtrap"? "hotel"?)
-
Permalink Reply by John Ihlein on
-
My Oil Pan shield is Rev F 2.2
-
3D RoboticsPermalink Reply by Chris Anderson on -
Okay, that's foxtrap. The reset button in the IMU shield was fixed in rev H (hotel). But that shouldn't stop you from connecting to the Configurator--I use rev F boards all the time, without any modification. I think the problem must be something else. Are you sure your slider switch is in the correct position?
-
-
Permalink Reply by John Ihlein on
-
I'm using some modified code, so it does not matter what position the slider switch is in. I'm positive the issue is the board is not being released from the reset state. If the reset state is released, it will connect. It is just more often than not, the board stays stuck in the reset state. The 1st few lines of code in the setup routines have been modified to turn on an LED. If the LED turns on, indicating the board is running, it will connect.. If the LED stays off, it won't connect.
This problem only exists with the configurator. Using standard ArduCopter code and it's configurator, AeroQuad code and it's configurator, or my modifed code with the AeroQuad configurator. All behave the same way. And all work as expected with the Arduino serial monitor.
I need to get a scope out, but I'm beginning to wonder if the DTR signal timing is different on the Arduno serial monitor vs the configurators?
John
Social Networking
Top Content
Contests
Season Two of the Trust Time Trial (T3) Contest has now begun. The fourth round is an accuracy round for multicopters, which requires contestants to fly a cube. The deadline is April 14th.A list of all T3 contests is here.
Groups
-
ArduCopter User Group
1299 members
-
Documentation Editors
51 members
-
Melbourne
48 members
-
UK Ardupilot Group
111 members
-
Agricultural UAVs
137 members
Advertisement
© 2013 Created by Chris Anderson.
Powered by
