Tutorial Mjoy16 USB AVR Joystick

ok , I alredy know why don't i found this file. I search Mjoy16 all in one name, like on the 8th page form.

thank you for the reply and the files.

From the manual: If you are not using some of the axes then connect their signal terminal to the ground. Otherwise unconnected inputs may generate random inputs that might be induced from other inputs, external signals etc.

Can I do this by placing jumpers between - and signal, or is there another way to ground the unused axes? (might sound like a dummies question,,, in that case - it is! )

Fred

What diodes are being used in the button matrix on your board?

Orion

Any small signal/rectifier diode will work. I used the cheapest 100 piece pack of 1N4148 on ebay.

Well, if you dont have jumpers, to ground axis use some length of wire between - and signal...

Sokol1

I have used Mjoy for some hours driving and today I was driving in gtr-Evo with my diy pedals and shifter, but something strange happend: I was going to change car and track, but when i was ready to drive, the Mjoy stopped taking respons from the potentiometers. Now i cant get the potentiometers working again. have also tried to restart, change potentiometers calibrate etc, but there is no reaction. the Mjoy is recognised by my pc and the buttons are working. any ideas what happend, and what can be done with it?

Regards Fred

What is the state of the 8 joystick axis? All stay at 0?

First of all, check for hardware issues. Are you getting 5V on the (+), 0V on the (-) pins? Do you have a proportional voltage on the signal pin to the pot position? If you are not getting 5V, more than likely the inductor is fried. If you don't see the incoming signal voltage to vary 0-5V, either the wipers are connected wrong, or shorted to something.

If you see voltage changing on the analog inputs 0-5V that means hardware is fine, it will be firmware/software related or a zapped chip.

Hello Adam: First of all, I believe if something is wrong, its me doing something wrong, and I believe its a good job done on this board. The position of the axes is all zero exept x-ro is in the middle. I am not shure how to measure all this. It is 5v between + and - on the pot input. when i connect a pot its no changing in that value. I am pretty shure the wipers is connected ok (i know the smell of burnet pots ). Can you tell me where to put the multimeter to check it. all the axis stopped working at the same time, in the middle of a game. All was working fine before that . what is a zapped chip? All buttons working fine!

Edit: When connecting multimeter to Wiper (s) and + or - The value is changing when turning pot!

Regards
Fred

That confirms the IC is getting the proper analog signal.
Zapped chip is a fried chip. It could be partially damaged where only certain parts fail, hence your buttons can still work.

Have you played with the init, and auto center inputs? In the manual you can find more info on it but I don't think that is the issue.
I would reprogram the chip first to see if the firmware got corrupted. If that gives the same results (buttons work, axis dont), the ADC fried in it.

Sometimes I have played loading Mjoy with Init button pressed, other times not Gtr seems to find the proper setting anyhow. I might need a new chip,,, hm That might be hard to find, but i will try. What could have caused rhis barbecue? By the way there was no frying-smell from the board.

Thanks for always be a good help here!

Have you tried reprogramming it? If so, what happened?

Static or shorts can easily kill it without actually heating it up to smoke. Where are you keeping it?

I am keeping it in a plywood box I made for it. It is posible it has been som static. I am still learning and might not have been consious enough though I try. I cant program it before i have made lpt connection, but i will try that to (guess I cant use usb to program)

How did you program the AMC?

You can take the MOSI, MISO, SCK, Reset, 5V, Gnd, pins from the serial circuit on the AMC and connect it to the MJoy that is labeled for you already. Programming is same in PonyProg, just reprogram with the hex file.

Ofcourse!!! Something to do tomorrow then before celebrating a new year! (late night here) Hopefulle more g-forces next year! (working on proper cooling for my new dsmh-bridge)

Regards

Fred

Now i have tried to reprogram the mjoy in Ponyprog, but it seems to me there is something wrong with the atmega.

In port setup i get probe OK

When I try to read and write flash i get either Device missing, unknown (-24) or Unable to probe, bad device or device locked (-25)

If I ignore error when reading from the device, i get read successfully!?
Also device missing trying to read or write security bits.

I am using the programming port on amc, and the same computer (old pentium with com port) and cable as I successfully programmed my amc with.

I have a new atmega on its way ordered on ebay, and hopefully i am able to program that.

My big question is. How could the atmega (programmed by Frakk and working fine) suddenly in the middle of a game be destroyed??? i do not want this to happen again. My Mjoy is very vell built by our friend Frakk here.

That is very strange Fred. I don't know how PonyProg reacts to protection fuses, but it is possible that somehow those got corrupted, along with the firmware contents. I would like to try re-programming it with a proper tool if you lived next door.

I don't know how it happened, maybe a random error, maybe something is haunted in your house. Try again with a brand new chip and see if it happens again.

I have restored a very old timber-house where my workstation and sim is stationed, so haunted,,,who knows?, but I guess its just me beeing unconscious It would be a good thing having you in the neigborhood, that is for shure, and I would happily borrowed you all my kids lego too ;D I think I am the only active norvegian in this forum... Update when I have my new atmega.

Fred

New atmega, still no luck My mjoy was working well before, so i believe there is just a small error, but i need help to find it. Is there other components that can be distroyed? I still get the unknown device message in ponyprog. Unable to read fuses, and unable to program it. I read somewhere that the atmega device can be locked, but i do not really understand what that means and how to overcome it.

Fred

Are you powering the board from the USB or the AMC? Without power there is no communication.

Can you verify that the programmer circuit works properly with the At8535 in the AMC?

A brand new chip cannot have lock fuses programmed.

Powering from usb.
Programmer circuit will be checked. it was ok when i programmed the 8535, but that was a year ago. (could be haunted since then )
If I set the fuses wrong first time, will it then be locked?
As you said once: most electronic failures are mechanical, so i guess i find it there... :thbup:

Fred