• Madox
  • Busy Chum
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  • From: Sydney
  • Registered: 2008-04-12
  • Posts: 121

Topic: Automotive / Rollingstock Chumby - Seeking Duane/bunnie help

Bought a chumby last year with the insiders deal but haven't had much time to play with it other than to use it as intended (aka glorified news/weather display and alarm clock).

Having cracked the touch screen on the GP2X i bought for hacking brings me back to the Chumby wink

Since I'm at a hair salon with no access to the chumby, I have a few questions on how I could adapt my chumby to use as a speedometer display on
a)A Car
b)A Train (yes a train)
---
The car speed signals would be accessible via CAN bus (Mazda style).
The train speed signals would be either of 4-20mA speed signal or Ethernet multicast messages

The concept is to pull apart a chumby (which i did last night), remove both the wifi riser and the daughterboard, add a custom daughterboard with CAN/analog/wired ethernet hardware.

The daughter card would most likely be based on a LPC2378 ARM7 for its dual CAN + USB + Ethernet.

The questions for Duane/bunnie are then :-
1)What is the easiest way to interface to the Chumby mainboard?  SPI?  USB?
2)When is firmware 1.6 due to be released to fix the wired ethernet smile)))
3)Would removing the daughterboard and thus associated accelerometer etc impact chumby running?
4)Was the linux kernel for the chumby compiled with multicast enabled?

smile Sorry for the flood of questions, just bored at the salon thinking about the chumby.

Madox's Website

  • From: Singapore
  • Registered: 2006-08-26
  • Posts: 188

Re: Automotive / Rollingstock Chumby - Seeking Duane/bunnie help

SPI is available on the chumbilical. USB is available on the back panel, and by transitivity, on the chumbilical. So both are good options.

Removing the daughtercard should have no effect on chumby operation, if you can get power into the board through another means. The accelerometer will just return values based on random noise in that case.

Not sure about the multicast question, or the wired ethernet question--those are more for Duane!

7BAA 2E53 01C1 DCFF 497B  E7F0 9699 A303 78F0 D9B9

bunnie's Website

  • Duane
  • Duane
  • Blue Octy
  • Offline
  • From: San Diego, CA
  • Registered: 2006-08-24
  • Posts: 8,199

Re: Automotive / Rollingstock Chumby - Seeking Duane/bunnie help

There is no firm date for the release of the 1.6 firmware, but I think you can expect it sometime in May.

I believe that multicast is enabled in the kernel, but not 100% positive.  You could download the kernel source and run 'make menuconfig' and see how it was set up.  If it's not enabled, let us know and we look into it for a future update.

Duane's Website

  • Madox
  • Busy Chum
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  • From: Sydney
  • Registered: 2008-04-12
  • Posts: 121

Re: Automotive / Rollingstock Chumby - Seeking Duane/bunnie help

Thanks to both bunnie & Duane.  Had a bit more time to look through the schematics and a very very quick peek of the source, both of which changed and/or firmed up my ideas somewhat.

The Chumbilical only brings out CSPI1_SS0 and CSPI1_SS1, which are being used for the Accel and EEPROM respectively.

So if I go the SPI route... the maximum devices I can have is 4 with the help of a 2 to 4 demux.
1 for the High Speed CAN Bus
1 for the Medium Speed CAN Bus
1 for an ADC
1 spare for good measure

Then I can skip the LPC ARM7 LPC and code directly on the Chumby smile Wheeee

I also noticed the USB-Serial drivers support almost every imaginable device so I guess thats a fallback option too.

Is there anyone else interested in this?  If not I'll just hide and code, if so I'll post some information up as well including some of the Mazda CAN protocol information I deciphered a couple of years back (still valid, talk about projects on hold!).

Madox's Website

  • Madox
  • Busy Chum
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  • From: Sydney
  • Registered: 2008-04-12
  • Posts: 121

Re: Automotive / Rollingstock Chumby - Seeking Duane/bunnie help

Actually one more question...

Where is it that the Actionscript "ASnative(5, 60)" calls are in?  Is it in the non-open flash player?  Is there another way to create additional ASnative calls to say new kernel drivers we make ourselves?

Madox's Website

  • Duane
  • Duane
  • Blue Octy
  • Offline
  • From: San Diego, CA
  • Registered: 2006-08-24
  • Posts: 8,199

Re: Automotive / Rollingstock Chumby - Seeking Duane/bunnie help

The ASnative calls are additions we made to the Flash Player, which is, indeed, closed.  There is currently no way to add more to the player without the source code.

We're adding ASnative calls to do serial I/O and better support for talking to local executables, which might address your issues.  At the moment, we typically use small HTP daemons to expose services to the Flash Player (for instance, chumbipodd).

Duane's Website