Rfc: Tilt/accelerometer - Would You Want One?

[jdh2550]

Just out of interest, how complex would an external I2C solution be? I know pretty much zero about electronics, but I do know how to solder (I used to work in a factory soldering PCBs all day long). Assuming I'm using an I2C module like this would it just be a case of soldering the wires to the relevant pads on the board and mounting it in an enclosure? How would multiple modules be connected?



For an external solution you'll be using the AV connector port. This is a 14 pin plug and you'd use four pins from it Vcc, Gnd, and two of the UART2 (or maybe UART3 can't remember) pins as SDA and SCL. Then, you'd use OMAP firmware to configure those two pins to act as a "software based i2c" interface.

For an internal solution you'd wire up your SDA and SCL lines to the existing I2C bus which is used for the analog nubs (I think that's what MWeston said - look over in the Developer forum).

In both cases you'd then need a driver available in linux to access that info. See these 2 pages:
http://www.linuxjournal.com/article/7252 & http://www.linuxjournal.com/article/7136

To add more than one I2C device you'd just daisy chain them together. SDA from device 1 to SDA on device 2 and SCL from 1 to SCL on 2.

Hope that helps?

EDIT: BTW, this is the device I plan on using: http://www.sparkfun.com/commerce/product_i...roducts_id=8658 - it's less accurate/sensitive but less expensive.

 

[Svartalf]

FYI after very much googling it seems the device I want already exists. It's a little more expensive than I was hoping but Linux software is available. I know you guys are looking at internal solutions, but the info might be useful for some reading this thread


Reading the info from the website, basic function is HID based. More advanced function is supported via a decent enough looking interface available.

 

[Klepto]

Hope that helps?

I'll take that as a yes, in which case it helps a lot, thanks. Software I can at least attempt with some hope of success

 

[jdh2550]

Hope that helps?

I'll take that as a yes

Hey, I'll never, ever, ever use 1 word where 1,000 will do!

 

[Klepto]

Hey, I'll never, ever, ever use 1 word where 1,000 will do!

And I'm glad of that, it was one of the most detailed yesses I've ever had

 

[DAP]

One could emulate a gyro by using 3 3 axis accelerometers located in different locations on the Pandora. The rotation information would come from the differences between them.

 

[Hawkey]

Don't know if you know this shop here, there are some pretty chips + PCB that could be interessting (if there aren't too expensive compared to other offerings)...

But I still got a question about this device (just know the old Thread where jdh mentioned his plans): Will it contain some kind of Rumble effect too, that could used in games/emulators (beside the accelerator movement controll) ? I don't want to change the battery or something else, just to make a vibration avaibale at the Pandora. Therefore it would be great if this extra could be implented and I guess the price of the whole thing shouldn't be more then 50€/70$

 

[EdCa22]

Don't know if you know this shop here, there are some pretty chips + PCB that could be interessting (if there aren't too expensive compared to other offerings)...

But I still got a question about this device (just know the old Thread where jdh mentioned his plans): Will it contain some kind of Rumble effect too, that could used in games/emulators (beside the accelerator movement controll) ? I don't want to change the battery or something else, just to make a vibration avaibale at the Pandora. Therefore it would be great if this extra could be implented and I guess the price of the whole thing shouldn't be more then 50€/70$




Hmm. Rumble packs are not what we were talking about. AFAIK rumbles are just a motor with a weight on it (like vibrate functions in a mobile phone). I imagine it will be hard to power from the EXT port though, but you might be able to do it from USB. You'd need some sort of controller as well though. Also, rumble would probably play hell with the accelerometer. Guess you could maybe put a high frequency filter on it.

That accelerometer looks interesting. Quite expensive though.

 

[Hawkey]

Hmm. Rumble packs are not what we were talking about. AFAIK rumbles are just a motor with a weight on it (like vibrate functions in a mobile phone). I imagine it will be hard to power from the EXT port though, but you might be able to do it from USB. You'd need some sort of controller as well though. Also, rumble would probably play hell with the accelerometer. Guess you could maybe put a high frequency filter on it.

That accelerometer looks interesting. Quite expensive though.

I am aware that with tilt/accelerometer isn't a Rumble Pack meant. Just want suggest, that it would be good if one could be implanted in it (dont't know if this would be possible, but were probably more interesting, since the vibration could influence your handling/move controll)

Hopefully see what happens with this plan/work in the future :rolleyes:

 

[jdh2550]

Hmm. Rumble packs are not what we were talking about. AFAIK rumbles are just a motor with a weight on it (like vibrate functions in a mobile phone). I imagine it will be hard to power from the EXT port though, but you might be able to do it from USB. You'd need some sort of controller as well though. Also, rumble would probably play hell with the accelerometer. Guess you could maybe put a high frequency filter on it.

That accelerometer looks interesting. Quite expensive though.

I am aware that with tilt/accelerometer isn't a Rumble Pack meant. Just want suggest, that it would be good if one could be implanted in it (dont't know if this would be possible, but were probably more interesting, since the vibration could influence your handling/move controll)

Hopefully see what happens with this plan/work in the future :rolleyes:

That looks exactly like what I was thinking of doing and in the price range of what I was thinking was possible 27.8 euro = $35. You'd still need to add an enclosure (a case) and a connector. Depending on what you want to achieve you could simply velcro the thing to the bottom of the pandora and run a short cable from there to the port. You'll likely have to plug it into the USB OTG port because of the speed issue with the standard port.

Great find! The pre-built USB devices I found were in the $90+ range.

Theoretically an I2C version can still be smaller and less expensive though. Because of this an I2C version is also more suitable for internal mounting. To satisfy my desire to do a hardware project of some sort I may still follow through with an I2C version.

However, AFAIK, if you want to add a USB tilt control to your pandora Hawkey has found you a solution: JoyWarrior24 F8

(Ed - $35 for an almost complete solution seems quite inexpensive to me - am I missing something?)

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Now, as far as rumble packs go - I'm not as interested in solving that problem. As Ed mentions a rumble pack probably isn't a good match with an accelerometer - but it could be done. The other thing is - how does the game control the rumble? Is there a standard interface used? How would one make rumble work with games?

 

[Hawkey]

Good to hear that the price fits (wasn't sure what you still need to add, until it is complete), you had just to calculate that you have to pay the VAT and the transport costs too. Hopefully enough people are interested in this addition (from approximate 200 readers or 100 voters), so that you could order at least ~ 50 to get a discount [then it just costs 18,37 EUR/23.62 $ + VAT/shipping]

For the rumble effect: It was just a thought that I had when I played last time a PS1 game. An integration of such a vibration while you use an emulator (PSX/N64/...) to play a games which support it would be unbeliveable, not to mention that you could integrate this feature too in some homebrew games.
As an idea you could drive a car and if you crash, it vibrates. Moreover you could fight and "feel" the hit when you got punched (sure it first have to be implanted in a software). Furthermore you could also try something new and create a game, which relys at this rumble effect (short thought: a deep cave, you controll a mine worker, controll him by moving the pandora and goal is to escape by "feeling" in which direction the vibration is more intensiv => the exit).

If it won't work or just with problems at the accelerometer, then its okay to left it (still got another port to try my best ). I allready talked with some people at the german forum who are interested (but no "clear" announcement how you could use it practicly, just something about an akku with vibration).

Lets keep us informed about the project "add" for the Pandora

 

[jdh2550]

Y'know - some people have no sense of humor. (hey, this isn't a new thread!)

 

[jdh2550]

Good to hear that the price fits (wasn't sure what you still need to add, until it is complete), you had just to calculate that you have to pay the VAT and the transport costs too. Hopefully enough people are interested in this addition (from approximate 200 readers or 100 voters), so that you could order at least ~ 50 to get a discount [then it just costs 18,37 EUR/23.62 $ + VAT/shipping]

The good news is we in the US won't have to pay VAT. The bad news is that I can't find anywhere to buy it yet - I sent an email to their sales department. We'll see what happens.

As far as rumble goes - glad you found someone interested in pursuing it. Good luck and keep us posted. It might be worth getting an old N64 Rumble Pack and disassembling it.

 

[EdCa22]

(Ed - $35 for an almost complete solution seems quite inexpensive to me - am I missing something?)

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Now, as far as rumble packs go - I'm not as interested in solving that problem. As Ed mentions a rumble pack probably isn't a good match with an accelerometer - but it could be done. The other thing is - how does the game control the rumble? Is there a standard interface used? How would one make rumble work with games?



Yep, actually it is quite cheap, sorry. I was thinking of that chip in combination with a rumble pack. Or something like that. Trouble is, the rumble pack would require some kind of controller, plus that chip, will make it more expensive to use this accelerometer. But the complete solution appears ready to go, software and all.

The rumble might be useful...I've seen one of those tilt/ball rolling games on some phone (can't remeber which...htc I think - was def not the iphone) which used the phone vibrator to make you actually feel the ball hitting the wall as you tilt it. It was a very, very light rumble though, and I don't know if there was more than one or they used something else (as it actually felt like it came from the place where you hit). You would have to be careful because too much rumbling will make the accelerometer go all over the place, though you may be able to filter it as I said, or maybe minimise the rumbling. There's no real way of knowing what you could do for sure until you have it to play with. I heard sony had a lot of problems doing that for the ps3...though I think others have done it, so...