Posts made by Ken Conrad

@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!

@Bill-Trombetta First a tip - some in this group can become unruly when they see long pastings of terminal output - take a look at using 'Markdown' in your posts you will find examples of Markdown in use all over this forum - like I just did in that blue highlighted link. It is easy and helpful for the everyone.

Is this a complete listing of the startup? Typically, when the Omega boots you don't need to enter the boot menu ... are you having some other problem with the Omega?

Was there a reason why you aren't using Onion's recommended procedure to update/ upgrade?

@Paul-Jobson When I was testing several external antennas on Omega2 I had best results by cutting the connection to the on-board chip antenna - with RF two in-series antennas is not better than one!

@Bill-Trombetta Yes, my mistake - at first look your Power dock looks like an Expansion dock. You are right, no UART on that dock. The serial connection for a terminal to the Omega is via Omega's TX0 and RX0 pins - your challenge is that THESE pins are not on the Power Dock's header (the TX1 and RX1 pins you found don't work for this - Onion tells the details here). However, the TX0 and RX0 pins are of course on the Omega2- see PinOut diagram To connect to these with your dock - you can either solder wires to the bottom side of the board at those solder points, or use some wire- wrapping on those Omega pins - ether way, ensure good connections for a reliable terminal.

@Bill-Trombetta No need for the small USB to TTL UART board here - In your photo I see you have the Expansion Dock which has a UART for serial communication, why not use that for your Serial Connection, as explained here?

@Bill-Trombetta Some questions - How is your Omega powered? On an Onion dock or? Putty shows me that you are connected to the Omega via USB TTL, ie Serial connection. Are you using a UART separate from your dock or power supply? If so, have you connected the grounds together?

@Marcin-Debowski You really shouldn't need greater than 3.4- 3.5V at 500mA to power the Omega2 through a complete boot.

In my experience, a boot failure is caused by either insufficient current from the power source causing a voltage sag when there is a demand for more power ie when Wifi is initialized, or a poor connection in the (Dupont style) jumper wire ends. Look at those Dupont wire connectors - all inexpensive Chinese connectors should be suspect until proven to make good connections and carry the required loads! If any power connection is very loose or the wire itself is very thin that is likely your problem.

@Lars-Tobias-Skjong-Børsting I see no harm in trying 3.3V, but the Omega may not supply enough current for the device. Can you check the documentation for that board to learn what power it is designed for? Now I see the link to the board you are using. It is powered at 5V and made to work with the Raspberry Pi, which has 3.3 volt signal levels, so the signal levels are correct for the Omega.

This is what I would try - supply the board with 5V and connect the board's TX to the Omega RX1, board's RX to Omega's TX1, open a serial console to the Omega and see if the pair can communicate.

@Lars-Tobias-Skjong-Børsting I haven't used the MAX485 ... the RS-485 communication standard is from dozens of year ago. Please confirm that this chip will work with the 3.3 volt logic level of the Omegas and not supply a signal above 3.3 volts that the Omega UART is designed for. I mention this because the original RS-232 etc standard worked at 12 volts and other similar chips operate at 5 volt logic level. If this is the case for the MAX485 (I haven't had the chance to find and read the datasheet) then the higher voltage could damage the Omega UART.

Yes, those pins are for UART1 which is used for serial communication with other devices, but are the signal levels of the MAX RS-485 correct for the Omega2?? If not, you will need some level conversion. Onion has information about UART1 vs UART0 here.

On the Mini Dock you could connect to those pins by soldering wires to the bottom of the dock. For testing, an Expansion Dock or Breadboard dock would enable easier connections via jumper wires.

@WereCatf Ok, splash-proof keyboard for you!