Posts made by Lazar Demin

@rahul2413 said in spidev fails:

I am just reading the single register value of lora chip using python spidev by modified some bytes

Since the python spidev module correctly reads the register, we can conclude the Omega2 is able to communicate with your lora radio module and there is no show-stopping issue in spidev.

If the python spidev half-duplex transmission worked, and the C program doesn't work, I think it's safe to assume the C program is using full-duplex.

Again, my recommendations are:

1. Look at the C code to see if there's a flag or switch for full duplex vs half duplex
2. Consider using a software-based SPI bus to communicate with the lora module. More info in this FAQ post.

One more thing:

@rahul2413 said in spidev fails:

I am sharing code can you tell me whats wrong with it.

This is a very large ask for a community forum. In my experience, the best way to resolve and debug technical issues on a forum is through collaboration rather than throwing the whole problem at another user. Please keep that in mind

good call!

@luz said in SPI SSD1306 Display boot problem:

maybe it would make sense to mark the MOSI pin red in the datasheet too?

Released v1.9 of Omega2S datasheet and v1.2 of Omega2 datasheet that includes SPI MOSI as a pin that's important for boot and must be floating.

@luz said in SPI SSD1306 Display boot problem:

And btw., the MT7688 datasheet links you have in the onion docs no longer work

Thanks for the heads up! Updated the link to a copy that Onion hosts, so this should work indefinitely.

Question

Looking for a way to probe the hardware to reliably detect if it is a Omega2/2S (64MB MB RAM, 16 MB Flash) or an Omega2+/2S+ (128MB MB RAM, 32 MB Flash)

Why is this useful?

If an Omega2+ is flashed with Omega2 firmware, the software (like ubus call system board) will identify it as an Omega2 regardless of the hardware differences.

We need a way to identify the actual hardware on the device to determine if it is an Omega2 or Omega2+

Solution that works from Linux Userspace

In the kernel messages (which can be viewed with the dmesg command), there is a line like:

[    0.358842] m25p80 spi0.0: w25q128 (16384 Kbytes)

or (in newer OpenWrt versions):

[    0.639801] spi-nor spi0.0: w25q256 (32768 Kbytes)

This is a message from the spi-nor kernel driver after detecting the actual flash chip. So it is not dependent on the flash size that is baked into the firmware image, but shows the real size of the flash chip. Both of the example lines above are from a firmware made for the Omega2. The first is run on an actual Omega2, the second shows 32M so it is a Omega2+.

The only gotcha with this is that the dmesg buffer is not infinite and will loose older lines when too many new ones arrive. This means detecting the flash chip size needs to be done shortly after startup.

So I put the following line into a startup script (e.g. /etc/rc.local) :

dmesg | sed -n -r -e '/spi0.0: .*w25q/s/.*(w25q.*\))/\1/p' > /tmp/flashchip

With this, the chip name and size is captured and can be read any time later from /tmp/flashchip to detect an Omega2(S)+ vs Omega2(S)+.

Credit

Solution found and published by @luz: https://community.onion.io/topic/4212/any-way-to-detect-an-omega2-when-running-with-omega2-fw

@luz said in Trying a lot but ssh root@hostname instead of ssh root@ip does not work:

Or you can use the so called DNS-SD (service discovery), which is a sort of distributed name server. The Omega2 supports this out of the box using the avahi software. This allows you to use youomega.local. style hostnames, however only from computers/browsers/apps that support this (macOS Terminal.app does out of the box, but otherwise usually you need to install a DNS-SD browser on the system you are connecting from before you can use *.local. hostnames)

@thinklearndo That's awesome, great project!

Do I understand correctly the setup app is meant to be run on a full-fledged computer and not the Omega?
And the setup app then uses SSH from the browser to write the encryption key to the Omega2?

@rahul2413 said in spidev fails:

but not in same index but in [index-1] so when i try to read previous index using xfer3 it reads correctly.

Sorry, I'm a little confused. Does this resolve your issue?

@rahul2413 You'll need to double-check that the program is actually using half-duplex SPI. Some programs have a full duplex vs half duplex switch.

Another option to explore:
Since LoRa radios have a pretty low datarate, you can also get away with using a software-based SPI bus. More info in this FAQ post.

@rahul2413 looks like you're trying to do a full-duplex SPI transaction. The Omega2 family does not support full-duplex on the hardware SPI bus.

Half-duplex transactions will work fine. More details in this FAQ post.

If you absolutely need full-duplex, you can try using a software-based SPI bus.

Half Duplex SPI Transactions

If you're looking to do a half-duplex SPI transaction (where Chip-Select is held active between blocks), check out the xfer3 function in the python-spidev module.

Details:

• In the python-spidev module readme
• An example of usage in a community thread

If you absolutely need full-duplex SPI

The Omega2 family does not support full-duplex transactions on the hardware SPI bus, but you can make a software (bit-bang) instance of an SPI bus that will support full-duplex.

More info on software-based SPI buses in this FAQ post.

@crispyoz good idea! Added FAQ post here: https://community.onion.io/topic/4834/faq-how-can-i-control-the-gpios-from-python-is-there-an-oniongpio-module-for-python3

pyOnionGpio was written as a quick and dirty wrapper for the sysfs gpio interface way back in 2016. We don't recommend using it for anything other than a hello world.

Better Options

There are other better sysfs gpio libraries available for Python3:

• https://pypi.org/project/gpio/
• https://python-periphery.readthedocs.io/en/latest/gpio.html
• https://github.com/vitiral/gpio

Let us know how it goes!

@Jim-W reposting response from this thread:

pyOnionGpio was written as a quick and dirty wrapper for the sysfs gpio interface. I wouldn't recommend using it for anything other than a hello world.

There are other (likely better) sysfs gpio libraries available for Python3:

https://pypi.org/project/gpio/
https://python-periphery.readthedocs.io/en/latest/gpio.html
https://github.com/vitiral/gpio
Let us know how it goes!

@ChMsT420 See this documentation article: http://docs.onion.io/omega2-docs/running-a-command-on-boot.html

@sriharsha-phd You can't retrieve an RGB image, but you can get a grayscale image.

See the distancePlusGrayscale.py example program for more details:

• Info on the example program
• The example program source code
• And the Tau Camera API Reference & Documentation

@Pete-R Maybe try logging in to the helpdesk portal with a new/different email?

If that still doesn't work, please post a screenshot of the error you're seeing.

Agree with @crispyoz's recommendation to clean the contacts. If it were a hardware issue or manufacturing defect, it likely wouldn't have worked at all.

I also recommend checking if the contacts have been damaged during SIM card insertion and removal.

@jasoneer I will look into this and get back to you.

Out of curiosity, what kind of modifications are you making?

@jasoneer Try again using the very latest build (b253).

It looks like the kernel checksum changed when we released b253:

(screenshots from http://repo.onioniot.com/omega2/packages/core/ and http://repo.onioniot.com/omega2/images/)

More info on openwrt kernel checksums here.

@Oziesin it looks like your device is running the Omega2 LTE firmware. In this firmware, the device is omega2lte.
However, it's compatible with all omega2p firmware.

Add a -f argument to your sysupgrade command and it should work fine.

@nro The power supply voltage should be 5V (+/-5%)

How do the power issues present? A good place to look would be making sure enough current is supplied - the cellular modem is especially power hungry.

Btw the hardware design of this product is open source, schematics and more can be found at https://github.com/OnionIoT/Omega2-LTE