Better AC DC detection

Hi,

I know similar topics have come up before, but I can't find any reference to my idea.

Hijack is able to Force AC mode depending on tuner ID or presence of tuner serial loopback. However, IIRC, this does not allow one to perform flash uploads while the riocar is powered from the dock connector.

Something I've noticed about the dock power connections (and correct me if I'm wrong please) is that the ignition sense is wired together with the positive lead of the AC connector. Connecting +12V to the dock's ignition sense and 0V to the dock's earth seems to power the player up exactly as if power were coming from the AC connector.

The dock's permanent +12V connection is wired totally seperately.

My question is this. Has anyone given thought to building a very simple N.C. switching circuit powered from the permanent +12V connection and connected in parallel to the mechanical switch on the AC socket? Preferably a solid state circuit, but a relay should work fine as well. Has anyone experimented with this idea?

To elaborate, when the player is docked at home, the power is connected to earth and ignition sense. Permanent +12V is left unconnected and in so doing, the switch is closed and the player thinks it's connected via AC. When the player is in the car it has to get +12V to Permanent power for the sleep/unsleep function to work on ignition. When +12V is connected to Permanent power, the switch is in an open state and so normal car operation is detected.


Thanks,
Aragon

Back in Black comes on, and suddenly my empeg stops working?

Sorry for not having more intelligent commentary.

The ONLY way to have the player's permanent "boot block" program allow flash upgrades is to have an object inserted into the AC power jack, such that it opens the small integrated switch therein.

However, flash uploads are perfectly possible (and commonly done) in docked mode -- if a Hijack kernel is already installed, newer ones can be uploaded rapidly using the ethernet port, and complete player software upgrades can also be done over ethernet (Linux only, at present).

I suppose we could duplicate the "boot block" loader into the main Hijack kernel code, and then people who want/need the slow method could also do uploads in docked mode.

Cheers

Yes. What I'm suggesting is connecting a second switch in parallel to the switch in the AC power connector which will make it look like the player is running off AC when, in fact, it's running off the power from the docking connector.

Are you certain the switch opens when the AC plug is inserted? I haven't tested it, but I would have imagined the switch would close, ie. the switch is normally open. Can anyone confirm this?


Thanks,
Aragon

In reply to:

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Are you certain the switch opens when the AC plug is inserted? I haven't tested it, but I would have imagined the switch would close, ie. the switch is normally open. Can anyone confirm this?

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The switch is normally closed. Plug in the power jack and it opens.

Stu

Yea, you are both correct. I got adventurous and took my empeg appart just now.

This should be a fairly simple hack. Attached is a picture showing what pin needs to be cut. Once cut, something like a relay would need to be connected to the dock connector permanent power (red wire) and ground. The relay's normally open switch would need to connect between ground and the PCB side of the cut pin.

By doing this it'll emulate the action of the mechanical switch in the power connector. When the empeg is in the car it has to get +12V to the permanent power connector in order for the power-on-ignition feature to function. When this happens it'll close the relay thus completing the ground connection thus causing the player to detect Car mode.

When not in the car one can provide power to the player via the normal AC connector or via the ignition sense and ground connectors on the dock connector and it'll detect Home mode.

Cool, yes?

Cool, yes?

Yeah, especially for people like me with flaky leaf switches in our adaptor sockets. Let us know how this works out!