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chris
Unregistered guest
Posted on Wednesday, December 21, 2005 - 4:56 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hello Technobots,
I have just wired up my MD22 speed controller for the first time and i'm afraid I cant get any movement from it. Its on the bench with simple wiring, I have a MFA Como drill 919D series motor attached and I have 5 volts on the digital input and have set the device to run as independant RC servo mode. I scoped my RC channel input into the MD22 and its fine. I set my input voltage for the motor to 6.5 volts. I also checked all the wires as fine.

SO I am stuck, can you please offer fault finding advice, please. I havent had any signs of life yet.

Regards

Chris - Robotic Systems Ltd.
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 102
Registered: 10-2004
Posted on Monday, January 2, 2006 - 5:06 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hello Chris,

I'm sorry to hear you are having problems with the MD22. It is very rare to find any manufacturing problems with these.

You mention that you have "a MFA Como drill 919D series motor attached", have you connected both RC inputs? I'm quite sure that unless both RC inputs are connected, the controller will go into failsafe shutdown. You could also try the other channel as well to see if that one is operating or not.

Let me know how you get on.
Admin (Admin)
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Username: Admin

Post Number: 110
Registered: 10-2004
Posted on Friday, January 6, 2006 - 7:20 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hello Paul,
Just to put your mind at rest, I finally scoped the output of my servo driver and its only gnerating a pulse train where the signal is 3.3 volts pk to pk max. This is ok for RC servos but I realise your speed controller needs 4.5 to 5.5 volts. I have a voltage level adapter chip on its way so should hopefully cure the problem that way.

Thanks for getting back to me
Rob Grimm
Unregistered guest
Posted on Thursday, January 5, 2006 - 8:06 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hi Paul
I have a couple of problems with the installation of our MD22 speed controller which I suspect might be due to interference.
1) The robot sometimes steers in the wrong direction. Forwards/ Backwards always works ok but pushing the stick left sometimes results in the robot turning right and vice versa.
2) Firing the weapon results in the board either shutting down completely or going into full speed forwards/Reverse. Reseting the power to the board will mean the board will work fine untill the weapon is fired again.
Further info:-
The robots drive motors are a combined motor/gearbox unit with "CIM" written on them apart from that I don't know anything about them.
The weapon is a flipper fired by a 3 port valve switched by a microswitch and a servo.
Failsafes used are FS1's.

Any advice would be appreciated.

Thanks
Rob
Admin (Admin)
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Username: Admin

Post Number: 111
Registered: 10-2004
Posted on Friday, January 6, 2006 - 7:38 pm:    Edit Post    Move Post (Moderator/Admin Only)

Rob,

Hope you are well.

The MD22 was revised during 2005 to incorporate a RC failsafe. I have received any feedback to suggest if it is over sensitive which can be a problem with some failsafe circuits.

Firing solenoid valves will certainly generate massive pulses of electro-magnetic energy much of which will swamp our 27 to 40MHz band. It is especially bad when de-energising the coil. I always use a 1N4007 diode across the coil connectors (or in the coil connector plug). Remember that the white band on the diode goes to the positive supply. Now, this burst of radio interference would normally only cause a short term shutdown as the failsafe logic operates due to illegal RC pulse duration. To cause a CPU lock-up is something which whilst not unknown in the world CPU based speed controllers, is not something I have heard of with the MD22. Solenoid coils should not be drawing any more than a pulse of something like 2-5A, so a battery voltage drop should not be an issue unless the batteries are flat or faulty.

Where are you using the FS1 failsafes, on the weapon channel only?

Assuming it is interference which is most likely, have you worked your way through the EMI guidance note http://www.technobots.co.uk/discus/messages/164/166.html?1126724030

It is difficult to be of more help at this stage but let us know how you get on.
rob
Unregistered guest
Posted on Monday, January 16, 2006 - 7:31 pm:    Edit Post    Move Post (Moderator/Admin Only)

hi technobots,
i am doing a mechatronics hnc and have purchased a md22 h-bridge motor controller for my project,and am having a few problems with it.i have 2 como mfa re850 motors wired up to it(both work fine),a fully charged 12volt battery and the 5 volt logic supply too. but with it wired as per the instructions for rc servo mode with diferential drive,there is no output to the motors.i checked all the supply voltages from the battery and the rc reciever and they are fine. i then wired it up as per both analog modes, with 5 volt thru 2 potentiomrter, and still no joy. power to the board but no output to the motors.
i would appreciate you help on solving my dilemma. thanks
rob, mechatronics student, moray college
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 117
Registered: 10-2004
Posted on Wednesday, January 18, 2006 - 7:37 pm:    Edit Post    Move Post (Moderator/Admin Only)

Rob,

Whilst we can never discount a problem with a speed controller, just about every case has been down to user error or damage caused by the user during incorrect wiring up.

The fact that you have tried both RC mode and analog modes eliminates failsafe issues. It is rather difficult to diagnose a problem from afar, but I would ask that you double check your batteries (recently spent some 6 emails with a customer with a MD22 only to find that their 'fully charged' batteries were actually flat) the connections and the dip switch settings. If still no joy, return the MD22 to us with your details and we will examine it.
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 147
Registered: 10-2004
Posted on Thursday, March 9, 2006 - 6:57 pm:    Edit Post    Move Post (Moderator/Admin Only)

Email reply

"hello paul,

both myself and collegue and instructor checked all the connections, we were getting 12.49 volts to the board from the battery, and we set the dip switches as per the manual. for the wiring, the battery was the last thing to be connected after checks from the instructor. i will e-mail my instuctor to see if he has had any joy with the md22 during the week, and if not will get him to send it back to you for checks.
thanks for you time to return my e-mail
rob"
Robert Grimm
Unregistered guest
Posted on Sunday, March 5, 2006 - 9:01 pm:    Edit Post    Move Post (Moderator/Admin Only)

Paul

After further testing of our MD22 speed controller this weeked I feel I am a little closer to the cause of the problems of erratic running. After receiving the board back last week I noticed that it had been tested in "RC Servo Mode" i.e one stick controls one motor and one controls the other. In this mode the board works fine with no problems!! However when using the board in "RC Servo Mode with differential drive" so the board does the mixing we get the erratic drive problems I described before. Could you confirm if on the recent test of this board whether it was tested in this mode?
With this new information I'm fairly certain its not a general interference problem but a problem more specific to this particular mode on the board.

Regards

Rob
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 148
Registered: 10-2004
Posted on Thursday, March 9, 2006 - 7:01 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hi Rob (Grimm),

Thank you for the feedback, I have contacted the designer for his response. Do you have a v-tail mixer or a v-tail mixer on your radio? Just taking your findings a stage further by wondering if we do the mixing outside of the controller whether the problem goes away.

Hopefully we will crack this problem
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 161
Registered: 10-2004
Posted on Sunday, April 9, 2006 - 5:50 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hi Paul

I think we've got this sorted now, their latest software patch means the board now behaves as I would expect.

Thanks

Rob
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 162
Registered: 10-2004
Posted on Sunday, April 9, 2006 - 5:58 pm:    Edit Post    Move Post (Moderator/Admin Only)

Rob,

That's really good news, what was an excellent speedo has got even better. We will be changing our stock to this latest version - V9 so that other users can use the latest steering algorithms.

In summary, the MD22 can now operate in two ways, the first references any turn with the speed you are travelling, the second way of turning operates in the manner commonly used in robots and other similar applications that need to be able to turn without throttle (lets you spin on the spot for example).
marc
Unregistered guest
Posted on Wednesday, June 21, 2006 - 12:50 pm:    Edit Post    Move Post (Moderator/Admin Only)

hello,

I would like to know about the dimensions of the MD2 board.

Thank you

Marc
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 215
Registered: 10-2004
Posted on Wednesday, June 21, 2006 - 6:43 pm:    Edit Post    Move Post (Moderator/Admin Only)

Marc,

I assume you mean the MD22 speed controller and for some reason those dimensions are missing from our website! The size is 110 x 52 x 25mm.
Dave Lang (Kronic)
Member
Username: Kronic

Post Number: 1
Registered: 6-2006
Posted on Friday, June 23, 2006 - 10:10 am:    Edit Post    Move Post (Moderator/Admin Only)

Hi,

I've just setup our MD22 inside our new featherweight and I seem to have a problem. If I run the system in RC Servo mode (controls on separate sticks) then I can control each wheel, both directions, individually with no problem. If I then switch to RC Servo + Turn mode then only one stick works (the direction channel) and the robot can only go in circles. It seems to be ignoring one of the channels. I have swapped the inputs over to prove that it's not the receiver at fault, especially seeing as it works in RC Servo mode, and I have checked to see if the switch lines get to the PIC ,which they do.

Pretty stumped now, the only conclusion I can come to is that there is some dodgy software fault in my unit which stops the internal mixer in the board from working.

Any suggestions?

Cheers, Dave Lang - Team Kronic
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 219
Registered: 10-2004
Posted on Friday, June 23, 2006 - 5:59 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hello Dave,

What version of controller do you have or when did you purchase it?

Paul
Dave Lang (Kronic)
Member
Username: Kronic

Post Number: 2
Registered: 6-2006
Posted on Saturday, June 24, 2006 - 8:24 am:    Edit Post    Move Post (Moderator/Admin Only)

Morning Paul,

Only purchased it a couple of weeks ago. One month ago at the most I would say

Dave
Dave Lang (Kronic)
Member
Username: Kronic

Post Number: 3
Registered: 6-2006
Posted on Saturday, June 24, 2006 - 8:30 am:    Edit Post    Move Post (Moderator/Admin Only)

Looking at your catalogue, the latest version (9) comes with a built-in failsafe and enhanced mixing functions. I believe that when I purchased the item this did not appear on the site so mine must be version 8 or less.

Depending on the version of the PIC, I may be able to re-flash the program if the hex code is made available. That might save having to return the item (possibly)

Cheers,

Dave
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 222
Registered: 10-2004
Posted on Saturday, June 24, 2006 - 6:36 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hi Dave,

Although the website was only updated in the last few days, we had our stocks updated to V9 well over one month ago so you must have V9 already.

What are your dip switch settings?

Paul
Dave Lang (Kronic)
Member
Username: Kronic

Post Number: 4
Registered: 6-2006
Posted on Sunday, June 25, 2006 - 12:17 pm:    Edit Post    Move Post (Moderator/Admin Only)

Set as per the instructions, think all off apart from 3 which is on.

Are the settings different for version 8 and 9?

Is there any indication anywhere that I can look for which indicates the software version? If I am on V9 then I won't be needing the other failsafe which we have ordered with you (which is on a back order cause the stocks ran out)

Cheers,

Dave