Is Omega2 usable without a dock?

Cameron Spitzer

I've got a well regulated, well bypassed 3.3V power supply and an Omega2. Pretty sure I can solder wires on without hurting anything.
Will the Omega2 run with only the two GNDs and the 3.3V VIN pins connected?
What's the 3.3V VOUT pin for, does it need a bypass cap to ground?
The FAQ says I can expect up to 200 mA current draw when the Omega2 is running. What's the current draw when it's hibernating? My application will be very power sensitive.

Thanks!

cas

@Cameron-Spitzer
The short answer is: Yes
However, there is more to it than just supplying 3v3 power.

Experience has shown us that the Omega2 is very sensitive to power fluctuations, requires a regulator at least, but a couple of caps are highly recommended together with the use of short, heavy gauge wire due to the current drawn when hitting wifi initialisation at boot.

Your first port of call should be the official documentation here: Powering the Omega with No Dock

Next, doing a quick search of these forums will yield a fair amount of discussion from the enthusiasts here on their own experiences and suggestions on making it a smoother experience for you.
Here is just one thread of many: [Resolved] Omega 2+, Powered without Dock, Shuts off after 18s

Having said all that, do not underestimate the power of having a spare expansion dock available when things go wrong. It is by far the simplest way to power your O2 and get direct serial access to the console for troubleshooting.

Welcome and Good luck !!

Cameron Spitzer

@cas Hi cas, thanks for your help!

I didn't have a fixed 3.3v regulator so I set an adjustable LDO regulator with resistors to 3.35V. Bypass is 0.1uF multilayer ceramic cap + 1000uF 10V aluminum electrolytic, total loop length less than three inches. That seems to be good enough. (For anybody trying to use an LM317, beware the dropout voltage is too high to use a 5.2V phone charger, you need a newer regulator or a higher input voltage. For those using an AMS1117-ADJ the resistors you need are 330 and 543=33+510 ohms.) My Omega2+ came up. It took a few restarts to get it through the initial setup and firmware download, and one more after I gave it our household WPA2 passphrase. I don't use Zeroconf at home, but it was easy enough to get the Omega2+'s IP address from the router logs.

Next I need to learn how to control suspend, hibernate, and resume, and take interrupts on I/O pin transitions. Wake from suspend on an I/O pin change would be really nice. That was pretty easy on Raspberry Pi and Arduino (interrupts only), just have to find the docs.

György Farkas

@Cameron-Spitzer said in Is Omega2 usable without a dock?:

Next I need to learn how to control suspend, hibernate, and resume, and take interrupts on I/O pin transitions. Wake from suspend on an I/O pin change would be really nice. That was pretty easy on Raspberry Pi and Arduino (interrupts only), just have to find the docs.

I'm afraid Omega2+ doesn't have suspend, hibernate, ... Power Modes - it can be Power On or Power Off only.

Probably you have already known we have some info about Omega2(+)'s SoC Mediatek MT7688 Datasheet

About GPIO Interrupts:
https://github.com/OnionIoT/gpioIrq
Omega2 current defects (Oct 2017) >> section GPIO Interrupts
There isn't ~~any~~ too much progress - I think.