A young man whom can not walk due to MS purchased a used Van with ramp. The controller that opens the door and lowers the ramp doesn't seem to work. They want to charge him $200 per hour to trouble shoot it and who knows how much to fix it. Needless to say a person on disability can not afford that. I have determined that all the limit switches are working and have applied power to all the motors and they are also working. From what I have read it appears that the Arduino could very easily replace the current controller, but alas I or he have zero experience with them.
The attached pdf has the schematics of the current system. We do not need the kneeling function, and would like to be able to control the open & close function via his cell phone Bluetooth maybe even open it and ramp down when his cell is within range.
Can anyone help us with this?
What model Arduino would accomplish this?
what shields?
what relays?
programming help?
Who is charging $200/hr for this, a BraunAbility workshop? It does seem a lot for an open ended diagnostic, but they would be best placed to diagnose any fault. Maybe push them a bit harder for a fixed price?
You could try shopping around. I'd have thought that a competent auto electrician would be able to quickly localise the problem, especially with the fairly detailed parts diagrams.
Alternatively, since you have been able to test the limit switches etc. yourself, you may have a good chance of a successful diagnostic too. Could be something simple like a blown fuse in the car's fusebox or in the controller unit (do you feel that lucky though?).
I don't see anything on the Braun website, but surely any company that provides detailed parts diagrams with part numbers must be able to supply those parts to the consumer. How much does a replacement controller cost?
I appreciate you want extra features like Bluetooth (is the keyless transmitter mentioned on the second page inadequate?), but a project like this isn't trivial to do, even if you have access to the vehicle. There may be safety, security and liability implications. Unless you find someone, ideally local, to do it on a charitable basis it's going to cost much more than $200.
Personally I'd be trying to get the ramp and vehicle in use as quickly as possible by just fixing what's broken. If (and only if) you have a genuine interest in electronics and want to spend the time, then the other stuff could be done as a slow burn project.
the lowest quote so far is 150 per hour to trouble shoot.... in order to get him up and running I have installed a winch switch to raise and lower the ramp, he still has to open and close the door which he can just barely accomplish. I have checked all fuses and all relays, even the manual switches do not work, this led me to believe that the pmm module is toast although it has power and blinking lights. I do agree it would be nice to get the existing system running but he can not afford an open ended 150 per hour. I have donated my time to help and have no problem buying the boards if we can make them work.
Thanks for your reply and the time you spent looking into it.
If you ask someone else to look at it, for a small fee such as $30 an hour, but that person doesn't know what to look for and has no idea how everything is wired, the time spent for this person just to figure it all out (before even starting to implement a replacement) will quickly push your bill way beyond what that $150/hr person would have cost you to actually fix it properly.
He can not afford to pay an authorized dealer (whom is the only place parts are available) to fix this.
Hence I have installed a switch as a work-around.
Is there anyone here that knows enough about the arduino to:
Advise me what is the best model to operate this system?
What additional parts I would need? shields? relays? Etc
Would anyone be able to assist in the programming?
I do appreciate the thought and time that went into the above replies, but we are talking about an individual that could only afford this van because it was practically gifted to him and to fix the existing $18,000 system is simply not in his or my ability to pay. MS is a terrible disease that has stolen his ability to walk and opening and closing the door will soon be beyond his ability to do also. Since I have bypassed the system with a winch switch to operate the ramp there is time to try and work around some of the other features. I have some experience with PLC's and could replace the system with one however they are much more expensive and the operating voltage is a bit more inconvenient but could be overcome.
Moreover by replacing the brains of the system with anything would allow him to bypass the High cost of the Authorized Dealer....And he could possibly learn how to trouble shoot and repair the new system on his own he next time....
dbake:
Advise me what is the best model to operate this system?
What additional parts I would need? shields? relays? Etc
How many motors to control?
What type of motor are they?
What is the rated current and voltage of those motors?
Do they need speed/direction control?
How are those motors wired exactly?
How are the microswitches wired exactly?
What is the power source for all this?
When you have the above all figured out in detail, we may be able to suggest appropriate motor drivers and other hardware for your system. You will then have to try and wire up each and every motor individually to figure out its wiring, its settings, and how to actually control it so it works the way you want to do.
Would anyone be able to assist in the programming?
What is the exact order of events? (press button a, run motor b for c seconds at speed d until it reaches switch e - etc)
How to prevent the motors from hard driving into stops and damaging stuff?
How to prevent the motors from breaking other things - e.g. a person in between the ramp and the doorframe?
When you have all of this written down in detail, go to your local makerspace and befriend someone that's experienced in programming and motor control, and who is happy to fiddle with this system to not only get it working but also get it safe and reliable, and all hopefully in a time span that allows the patient to still be around and able enough to enjoy the fully working ramp when this person is done.
That is, if there's someone willing to take the risk... malfunction is potentially pretty damaging to property and/or life!
Guess my answers will be somewhat redundant as it is explained fairly well in the attached pdf above along with a fairly good schematic. As I have stated earlier I have powered all the motors both directions they are 12vdc and being 12vdc they will require a change in polarity to reverse direction. all the limit switches are n/o and work. I do not believe any of the motor drive fast enough to require a de-accel time, more redundancy we are currently using a winch switch to operate the ramp and I havent installed any cutoff of power when the ramp lower switch or raised switch is hit - no damage so far and we are talking about a person running the switch with very poor dexterity due to his MS.
As explained in the pdf when the open button is pressed the system verifies the trans is in park (checks switch)
unlocks door (checks switch)
opens door till limit switch active
kneels van - Not needed
lowers ramp till limit switch active
each operation depends on the last to complete & two n/o switches & dc to the motor in one direction or the other.
when close button pressed
raise ramp if down till limit switch active
close door till limit switch active
unkneels van - not needed
lock door (checks switch)
We are not trying to operate a cnc with a very small tolerance
As far as safety an liability as seen in the pdf there is currently no feature that would prevent an idiot from damaging life or limb now. However from what little I know of this arduino there seems to be some proximity devices that could be integrated into the system making it safer than it is currently. It is a sad state of affairs that in today's world we must protect people from themselves but it is what it is.
If you are going to refer folks to the PDF then it would be worth mentioning the exact vehicle details and/or which wiring configuration diagrams apply to the specific vehicle. There are a number of quite similar diagrams which I assume are alternate configurations or different model years.
Mention your location as well, in case someone is local to you.
Figuring out which physical wire is which one in the pdf is another challenge.
No word on the motor current yet, an essential parameter for selecting your H-bridges.
dbake:
We are not trying to operate a cnc with a very small tolerance
No, too bad, as that'd be a lot easier with less consequences if things do go wrong (what if your contraption does not react to the limit switches or control buttons?), which will happen a lot during testing.
Several of the replies have had concerns about liability. I will be the one installing this and testing it and will there fore be the one liable. I believe that helping this person become self sufficient and mobile is the right thing to do. He lives in a town of 2500 with no lawyer :).
I have built some cnc machines in the past and retrofitted some tape drive cnc's to run on a windoze computer all used in a business 16+ hours daily by multiple operators, and currently own three cnc's, my programming is 1970's 4 byte machine which turned into 8yte and then basic followed by fortran some very early C and visual basic and a few varities of g-code lately I add some ladder which I am terrible.
so not totally ignorant of the process but am ignorant of the arduinos, there seems to be several incarnations out there which are the most reliable? I think that I can use 2 n/o relays per motor to reverse polarity? It appears to me that the mega is needed for the abundance of in-outs? however with the mega I would need to add bluetooth which by my investigates talks to the arduino like a keyboard through what basically a com port? it would seem prudent that the bluetooth needs to have some sort of security?
Again I do appreciate the replies and any help to shorten my learning curve.
wvmarle:
Figuring out which physical wire is which one in the pdf is another challenge.
I agree however I used it to test the switches and apply power to the motors so it is somewhat accurate.
No word on the motor current yet, an essential parameter for selecting your H-bridges.
these are not easy to access to find if there is even a nameplate on them, however if I can this weekend I will power them through a variety of fuses and see how low I can go before they blow. I thought I could use relays to reverse polarity?
No, too bad, as that'd be a lot easier with less consequences if things do go wrong (what if your contraption does not react to the limit switches or control buttons?), which will happen a lot during testing.
If the initial system was designed properly it should blow a fuse. I believe that with any machine there should be a E-Stop, this did not. If however I can do this tho bluetooth I think it would be prudent to add a e-stop to the program.
arduarn:
If you are going to refer folks to the PDF then it would be worth mentioning the exact vehicle details and/or which wiring configuration diagrams apply to the specific vehicle. There are a number of quite similar diagrams which I assume are alternate configurations or different model years.
Mention your location as well, in case someone is local to you.
For a relay based H-bridge you need at least four relays, and you have to worry about shoot-through and the current they have to carry, which you apparently still don't know.
Also when using relays you have no speed control whatsoever.