WereCatf - I'd guess by now you tried some aluminum foil under the Omega2 chip antenna, in place of your finger. Your post and this thread stirred me to experiment with the U.FL connector, add an external 2.4Ghz antenna then measure the signal strength with the Android phone app, Wifi Analyzer.

I disagree with some options and information expressed here and in the Onion resources. In my experience the onboard antenna doesn't work in unison with an external antenna, if fact they are designed to stand alone or be disconnected before you connect the external antenna, as done in these router antenna hacks TP-Link MR3020 and TP-Link WR703N. I've used these and they work.

Today I found that -

• yes, the RF feed for the U.FL socket is wired in parallel with the onboard chip antenna
• the onboard chip antenna is connected to the RF output by a tiny 0 ohm resistor/ jumper
• You can 'disconnect' the chip antenna by desoldering the 0 ohm resistor (I used an iron at 550 degrees F for ~20 seconds). For my eyes a magnifying lens was a must, and my soldering iron has a very fine point. There isn't much room on the board around this part ... A fine pointed knife could be used to cut this part off, refer to my photo. Done carefully, The change will be non-destructive and reversible with a small blob of solder.
  -Note that you will ALWAYS want to have either the external or chip antenna connected whenever the unit is powered, otherwise you risk damaging the RF circuit of the unit!

-For the external antenna testing I used a very directional 2.4Ghz PCB Yagi antenna with a maximum 11dBi gain. No testing outside yet - it rained all day. I measured the Omega2's Wifi signal indoors through two (wooden) floors, past a fluorescent fixture, etc. Compared to the stock Omega, there was no signal change with both antennas connected. After the chip antenna was removed from the RF circuit, the external antenna on the Omega2 boosted the signal by 10 to 15 dBm. I'll follow-up after I have tested some other antennas.

@perillamint- Without a JTAG port on the Omegas, makes sense to me.

Lazar (@Lazar-Demin) is the guy to ask, he did say this here a few days ago.

We hear what you guys are saying in terms of the community working [to] make the firmware better, so we will be open sourcing the firmware sometime in March as well

Thank you all for your continued patience and support for a young company

@David-Wallis95 said in Turning off wifi:

Is it possible to switch off wifi, and what current does it draw without wifi?

Yes definitely, you can easily switch off the wifi. On my bench an Omega2 draws 190mA with wifi on and 120mA with the wifi turned off.
Here are several ways to disable wifi -

1. During a session - in a terminal window the command "wifi down" turns off the wifi and "wifi" or "wifi up" turns it back on. Documented here near page bottom.

2. First I'll state the obvious... you will have a UART or appropriate dock for serial connection before testing this. By modifying the wireless config file, as mentioned here the Omega will turn off wifi while starting up.

3. You can toggle wifi off/on via a push button or a timer and the scripts, as detailed in those LEDE instructions. (edit - here the code tied to the "SES" button would be changed to work with input from a push-button on an Omega GPIO pin.)

@Luciano-S. ... Luciano, I agree that the Mini Docks serial connection isn't working with the Omega2s. In fact I posted about it here two weeks ago. My experiences may be a bit different; my year-old Mini docks do work well with Omega1. With Omega2, my PCs receive serial OK, but CANNOT TRANSMIT serial (ie via the RX0 pin) to the Omega2, so I cannot DO anything on the Omega2 with serial communication. A few people responded and basically agreed with my post. Frankly, I am amazed that more didn't say "Me, too", as I have found serial connection to be indispensable to learning and diagnosing (usually self-inflicted) problems in this gear.

The difference in how our computers fail to communicate via serial - is this a difference in how Linux handles the lack of a valid PC-to-Dock communication? In my case, Windows 7 seems to tolerate Mini Dock-to-PC without PC-to-Mini Dock communication.

Clearly, my issue is not a Windows serial set-up or Putty problem, as this bi-directional communication works fine with my Omega1s, with a direct wired USB UART connection to an Omega2, or with the Omega2s in the Expansion Dock.

How is it that all the Mini docks that I received in three orders shipped in early 2016 don't have working serial RX0 with the Omega2? Sure would like to use these Mini Docks .... I am primarily developing for portable and remote uses.

I looked at the Onions Mini Dock schematic. I found that our mini docks are not the same as shown in the design - I do not see a 3K resistor from PC TXD to ground on your or my docks ... I believe the purpose of this resistor would be to take a floating signal low. I tried soldering a 3K resistor there, to learn that I can't reliably solder with these tiny components!!

In the Mini and Expansion docks I measured and compared the bare (ie without Omegas), USB-cord-powered voltages to ground, to find that the RX0, TX0 and FW RST sockets DO respectively have DIFFERENT voltages. Based on this preliminary testing, I would conclude there is a difference in how the Omega1 and Omega2 communicate via serial RX0 and Tx0, since both work with the 2015 designed Expansion Dock, only the Omega1 (at least with MS Windows) works with the 2015 designed Mini Dock.

Again, I challenge anyone reading this to reply that their "Mini Dock (of any vintage) works fine with the Omega2 or Omega2+ via a serial connection" as described here- Terminal connection to Omega via serial . We need these docks and I for one welcome learning how to make it work.

Yes, the 16 hole 2mm headers are a bit rare. Is $1 per Omega delivered to your mail box cheap enough? Available here in a few days, after the Rooster holiday in China ends - http://www.ebay.com/itm/182057549028?_trksid=p2057872.

@Lazar-Demin Your web site product photos of the boards do say "Onion". Not a nitpick, just got it. My apology, these boards are Omegas and you are Onion Corporation.

@Patrick-Rainsberry Yes, those antennas have the U.fl connector and are for 2.4Ghz, so should work. In my experience, when I connected an external antenna to the Omega2 I had to remove a 0 ohm resistor to disconnect the on-board antenna, otherwise there was no Wifi signal improvement. See this topic for the details.

To check Wifi signal strength before/ after changes you might like free Android app Wifi Analyzer.

@Sycol Provided you wish to use the Omega as a USB host, provide a stable 5V of sufficient current and connect the grounds together, that should work.

@WereCatf Thanks for your clear and detailed pinout diagram. Wow, you had me excited for an hour re-considering a hardware fix for the old mini docks ... Actually, the Omega2 boots fine on those docks, there just isn't any communication to/ via the Omega2's RX0 pin - such as unresponsive keyboard, can't use Busybox, etc. Luciano and I wrote about our observations HERE and HERE.

I am curious, could/ does the Omega2 boot-strap determine which pins are the serial Tx and Rx?

@Peter-Mertz Congrats and good work to finding your fix. Now to help the others who find this in the future, please edit [resolved] to the end of the thread's title.

@Filip-Franik Parts redundancy is most helpful while working through problems with an inexpensive Chinese made board - your plan with multiple docks and Omegas etc will serve you to solve this problem, learn more about the Omegas and IoT.

Yes, don't try to use the UART on an Arduino, unless it is a 3.3V version. As recommended by György-Farkas, you could try one of the inexpensive SiLabs USB to UART boards on eBay connected to the Omega Rx0 and Tx0 pins - these boards are very useful to have to troubleshoot the Omegas. In which case you will also need a sufficient (1-2A) 3.3V power supply.

@Filip-Franik .59 is not very far into the boot. I have seen the 'jibberish' with loose Tx or Rx wires or power fluctuation or a funky UART. I suspect you are having an insufficient power problem. You have a Mini dock which should be Ok, provided you bought it with the Omega2 - Mini docks made last year had other problems with Omega2s. Have you tried with another USB cable? At another USB port on your computer?

With the early firmware versions the dock Reset button did not work - Onion admitted that was a known problem. You can reset the unit by momentarily wiring the reset pin high (with 3.3V).

Take a look at PySerial as described under "Using Python". Good luck with your project.

@john-frailey Sounds like you wish to disable the wifi hardware -

During a session you can disable wifi with the terminal command line entry "wifi down".

This change makes the Omega2 always start-up without wifi. Try that edit in the /etc/config/wireless file and let us know if that works for you.

@James-Thomas Will Cross compiling Mono for Omega2 work for you?

@luz said

unfortunately, after a seemingly perfect start with the patches from 20 days ago, the mt76 again behaves erratically for me as well.

Some days it works fine without a hitch for a long time, and then other days (like yesterday) performance is extremely poor and there are a lot of lengthy connection dropouts - without any change in the setup or wifi environment (as far as I can tell).

This is a guess based on a hunch ... looking at a discussion at the Linux wireless patch, referenced by the LEDE developers you sited - I see some code that changes a value based on the wifi channel. Perhaps some of these channel dependent values are bad code ...? Or, I have often seen Omegas jump to another wifi channel in the boot process when wifi is initialized. Here I used the free Android app Wifi Analyzer and sometimes see the Omega2 change it's AP wifi channel during the boot. Have you observed if firmware with the Mt76 patch might work fine on some wifi channel and not well on another? Perhaps there is a bug here, could that channel related value be wrong if and when the Omega2 switches the wifi channel?!

If you see some merit in this hypothesis, during the Omega boot you can observe the wifi channel behavior and assignment using an app like Wifi Analyzer, running on your phone or other tablet.

@Marcin-Debowski Yes baseline at 3.3V. I use a common bench power supply that has a variable volts output and displays the current drawn, in amps. I believe you have a similar power supply? I have my supply set to 3.3- 3.4V and the amp meter nicely displays the current required at that particular moment of the Omega boot, etc. Not a graph providing setup, but useful and accurate.

I just reread this thread. It is about various problems users had powering their Omegas, including your posts about tests with small Chinese made power supply boards. You mentioned powering an Omega with 5 volts. By accident I did that once with a bare Omega for an hour or more. It ran fine, but got quite hot. After that it always required at least 3.4v to boot completely and now it draws more current ... I believe the 5 volts changed or degraded something in that Omega.

What confuses me is your statement "recalculated from 7.0V to 3.3V". What did you do here? Did you calculate the amps at 3.3V by Ohm' Law for a constant load: A = 7/3.3 x (current measured at 7v) ?

To check your setup you could run this test - in place of the Omega wire a known resistive load, say 80 ohm 1/4 watt resistor or 16-20 ohm 1 watt resistor. Use your graphing to measure the current. Checking with Ohm's law, does the graph make sense?

@Marcin-Debowski Nice plot of the current under various Omega2 CPU loads. Your baseline of ~.40A is approximately double of the .18 - .20A that I and others measure with Omega2 at ~2% CPU. Any chance you are off by a magnitude of 2? Also, it seems odd that b < c when bCPU > cCPU. Can you reproduce that?

Would be better to have the Amp meter after the DC-DC convertor. Perhaps there is a voltage drop across the meter?

@David-Wallis95 said in Turning off wifi:

Is it possible to switch off wifi, and what current does it draw without wifi?

Yes definitely, you can easily switch off the wifi. On my bench an Omega2 draws 190mA with wifi on and 120mA with the wifi turned off.
Here are several ways to disable wifi -

1. During a session - in a terminal window the command "wifi down" turns off the wifi and "wifi" or "wifi up" turns it back on. Documented here near page bottom.

2. First I'll state the obvious... you will have a UART or appropriate dock for serial connection before testing this. By modifying the wireless config file, as mentioned here the Omega will turn off wifi while starting up.

3. You can toggle wifi off/on via a push button or a timer and the scripts, as detailed in those LEDE instructions. (edit - here the code tied to the "SES" button would be changed to work with input from a push-button on an Omega GPIO pin.)

@Marcin-Debowski, @Lazar-Demin

Question: is the Vin of 3.4V for the Omages a major concern? I liked the middle-sized converter but this is also the only with the Vout out of range (for both 5V and 12V Vin).

Seems powering the Omega2 with stablized 3.4V shouldn't be a problem - I just checked the Mediatek MT7688 datasheet to find (on page 32) under "Absolute Maximum Ratings" for I/O supply voltage 3.63V. I should add, since Onion hasn't published yet the schematic of the Omega2 or 2+, we don't have much idea of what lies between the Omega's V3.3 power-in pin and the MT7688 under the metal RF shield ... my guess is not much, other than a direct line to the MT7688 power-in pins.

Thanks for reporting your tests with these inexpensive small power supplies!