Auto-start on power on

Yeah, seems some error persists there:

xhci-tegra 3530000.xhci: Direct firmware load for tegra18x_xusb_firmware failed with error -2

Yeah. The thread seems to me meant for autostart.

The OEM integration guide documents why just jumpering the power button, or adding a capacitor, is not enough to make it start:

It also shows that all the 5V and 3.3V rails depend on the power-on button, so any external circuit would have to be powered by the VDD (12-19V barrel connector) input. I’m now looking for a suitable header where this can be tapped into.

And there’s even a schematic. Which looks a lot like what I guessed at above! Except it uses the “charger present” pin instead of the “power button” pin – apparently both can be used, except the power button needs to be held down longer (50 ms instead of 200 us.)

I thought Orbity was reported to autostart on power on.
It should be dip switch. To enable and disable autostart.

Yes, the Orbitty does do that. If the Orbitty matches your requirements, that’s a great option.

What we’re trying to do in this thread is figure out how to make the default NVIDIA carrier board auto-power-on.

Unfortunately, it seems that the VDD_IN/VDD_MUX/VDD_MOD signals (derived from the barrel connector without any gating other than the reverse-protection FET) are not available on any pins or headers, so unless the 4.75V present on the power button can actually source a bunch of milliamps, any automatic circuitry would have to be separately powered.


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could be of reference.

That’s an even worse solution. That thread is talking about re-working the Jetson module itself (!) to provide 5V standby, which seems like a really bad idea for most uses.

I’ll probe an off board to see whether something like USB 5V is still available, or whether there’s something else to tap into. 10 kOhm to 5V is also not so bad; a low-voltage microcontroller at low frequency (like an ATTiny85 at 2.5V running at 32 kHz) could totally run based on this.

related post there:

It seems that there is a way to let the Jetson TX2 SDK board autostart.

The document JetsonTX1_TX2_Developer_Kit_Carrier_Board_Specification.pdf states, on page 31:

When a Jetson TX2 module is used, an Auto-Power-On option is available. To enable this function, the CHARGER_PRSNT# pin must be tied
to GND. This can be accomplished by installing a 0Ω resistor at R313. This will allow the Developer Kit carrier board to power on immediately
after the main power is connected (without the need for a power button press. This will not work with the Jetson TX1 module.

I tried it and jumping R313 by soldering a tiny piece of wire onto it works, the board auto-starts when power is applied. It is located near the J27 header, see P2597_B04_PCB_assembly_drawing.pdf. Here’s the relevant portion of the board with R313 highlighted. (For reference, J25 is the power plug receptacle, MEC13 is the large capacitor and J27 the small flex cable header.)

The ridiculous settings of this forum don’t allow image posting for new accounts, so here’s the link: [url][/url]

Thank you @murstor,
works perfectly with Jetson TX2.

Hi! In case I follow @murstor instruction, I need to solder 0 Ohm resistor to R313. Where to solder another ending of the resistor?

Alternatively, is there a “safer” way to enable auto start without soldering? I am slightly afraid of damaging quite an expensive board.

Thanks so much.

I couldn’t tell you if that’s the right thing to do, but if you look closely you’ll see that normally R313 is not installed, and that there are two very tiny contacts for an extremely small surface mount resistor. Even a tiny blob of solder between those two pads would accomplish this (calling it a “0 ohm resistor” is just a way to label a short…no need to get an actual surface mount resistor).

You would need to be very careful to avoid static, you’d want to make sure the board has been unplugged and any capacitor discharged by holding down the power button for perhaps 30 seconds, so on. You’d want to use a quality small soldering iron, and you’d want to avoid holding the iron down long (consider over one second too long). A very fast solder job should be easy enough to do, but holding the iron down for any longer could easily damage such a small trace. I wouldn’t say you need to be a master of soldering, but you probably do need to have the right tools and some experience in order to quickly solder just the two pads without hitting one of the nearby pads.

If you have kapton tape, then you could cut a tiny window out of this and tape over the area around the two pads during the soldering to avoid any possibility of touching anything else. Taping would greatly reduce the need for being exact (though it wouldn’t reduce the need to be quick).

Thanks linuxdev for the protips. What he says is correct. R313 consists of two contacts for a surface mount resistor. It’s a bit too far to bridge with just a solder blob, but a tiny piece of wire will do it. It’s quite easy, and with such little amounts of solder you just need to touch the iron to the solder, wire and pad for a very short time. A little experience with soldering and a steady hand is desired though.

Sorry for bringing this thread back to life, but I saw couple of posts about Orbitty Carrier here. Did you guys manage to make USB sound to work?