1 Topic by Fake_Name (edited by Fake_Name 2008-10-17 00:17:15)

  • Registered: 2007-12-26
  • Posts: 8

Topic: Chumby Power-Outage Reset Dongle

Wheether the chumby should power on after a power-outage is a moot point.  It does not.

Aside from rather extensive bickering as to how it should have been, no one has looked into actually modifying the system to do so.

We have heard from bunnie that to make the hardware power on natively requires re-flashing the CryptoProcessor. However, I think that a somple 1-Shot timer that simply plugs in between the Daughterboard and the mainboard, on the chumbilical, is a much easier to implement solution. By having .1" pin headers on one side and a .1" connector on the other sid,e the installation can be made toolless.

It should be possible to produce "Auto Turn-on" dongles very inexpensively.

http://70.177.28.98:8080/s_images/Chumby_POR_1.png

Schematic was done in a very short peroid of time. I'll sleep on it, look it over tomorrow, and start on a PCB

I'd be interested in hearing how many people would want something like this. I can possibly produce some of them, for parts+labor. Est cost would be $20-40 each, though it's pie-in-the-sky right now.

I'd also appreciate hearing from the chumby staff. If you have any problems with me working-on/possibly-selling something like this on your forums, I'd be happy to go elsewhere, but this seems like it could be useful to a lot of chumby users (plus, I'm not trying to profit, just recoup any possible losses).

Note: Image hosted off a very unreliable connection. It should work...

Note 2: Altium is freaking out about the harness definitions for some reason, but the netlist builds fine. That explains the red "error" lines.

Edit: Stupid URL Issue. My website is bounced through 2 layers of DNS redirection because I refuse to pay $15 a month for dyDNS service.

  • Registered: 2007-12-12
  • Posts: 87

Re: Chumby Power-Outage Reset Dongle

The Schematic looks nice and it may work, I wonder if Bunny has any input

As fas as your internet connection/hosting, if needed contact me, I am a web host who can help

Read about my switch to Linux http://k-disk.com/home/page.php?page=My … OpenSource
  • Registered: 2007-12-26
  • Posts: 8

Re: Chumby Power-Outage Reset Dongle

Well, I've been insanely busy recently, so I've had little time to work on an auto-reset system.

Also, I'm not currently at home, and my server there apparently crashed, so the images are down (thanks for the hosting offer, but I already have to run my own server for several other reasons).

In any case, after a bit of thinking, I realised that since you have both an always on power connection, as well as a signal that effectively tells you the chumby is on (usb 5v power), a better way to design an auto-power-on system is a astable oscillator that's disabled when the chumby actually turns on, and enables the 5v regulator. That way, if theres a glitch or noise during the turn on process that causes the chumby to fail to boot, the reset circuit would continue to cycle untill the unit actually starts.

  • Registered: 2008-12-01
  • Posts: 30

Re: Chumby Power-Outage Reset Dongle

If you sell a working solution for 20 bucks I'll buy it.

  • Registered: 2006-09-22
  • Posts: 12

Re: Chumby Power-Outage Reset Dongle

Just checking in to see if you ever fabricated these or still want to make them? I need a few for a project we are working on (4-6 pcs).

Alternatively, any other method of ensuring the chumby starts running again after a power outage would be helpful as well (software or hardware).

  • Duane
  • Duane
  • Blue Octy
  • Offline
  • From: San Diego, CA
  • Registered: 2006-08-24
  • Posts: 8,197

Re: Chumby Power-Outage Reset Dongle

Note that "2009" chumbys *do* power back on when power is restored.

Duane's Website

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

Re: Chumby Power-Outage Reset Dongle

Hi Duane,

Assuming this change is a software update to the CP in the "2009" chumbies, would this code be released?

(http://files.chumby.com/hdwedocs/CP_ver1.zip is this old code for the CP...?  How current is it?)

Though for my always on (I don't intend to turn it off) I'm tempted to just add the lines
      if( powerState == 0 ) {  // if we are powered down...

    cmdPowerUp();  // then power up
      }
....

Madox's Website

  • Duane
  • Duane
  • Blue Octy
  • Offline
  • From: San Diego, CA
  • Registered: 2006-08-24
  • Posts: 8,197

Re: Chumby Power-Outage Reset Dongle

I'll ask bunnie to make sure the public code is updated.

There is no way to "update" the firmware over-the-air - the crypto processor can be updated only using JTAG, and that requires dismantling the device, and the appropriate equipment.  The crypto processor also contains the device's private keys, serial number, device GUID, and the Chumby Industries public key, so all of that would need to be captured from the current firmware image, copied into the new firmware image, and then reburned.

Duane's Website

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

Re: Chumby Power-Outage Reset Dongle

Thanks Duane smile

One of my Chumbies is already conveniently dismantled smile  Just have to look for my JTAG adapter...

Without the private keys/serial number etc, will the chumby still boot but only refuse to talk to chumby.com?

Cheers smile  Thanks for the reply!

Madox's Website

  • Duane
  • Duane
  • Blue Octy
  • Offline
  • From: San Diego, CA
  • Registered: 2006-08-24
  • Posts: 8,197

Re: Chumby Power-Outage Reset Dongle

Madox wrote:

Without the private keys/serial number etc, will the chumby still boot but only refuse to talk to chumby.com?

Pretty much, yeah.  Your device won't have a valid GUID and will likely be rejected when you try to activate it.  The public/private key infrastructure isn't currently in use, but will very likely be in the future.

Duane's Website