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frottier

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Posts posted by frottier

  1. I voted "saving money" since noone else did.

    :)

     

    The leading answer "it's better than most OEM stuff" is certainly true as well.

     

    Our beloved el cheapo manufacturer's mode of operation is: throw spaghetti on the wall and see what sticks. Looks to me like the OPi Zero and the NanoPi Neo stuck. At least this years survey from LinuxGizmos has them not completely losing – I guess this is related to the pricing.

     

    While a 10 – 20 $ save on a project does not matter that much to me, I feel like those baords are less likely to become abandoned by the community.

  2.  

    When I power down H3-devices I see quite different results.

     

    Normally I use 'sudo poweroff' which should behave like 'shutdown -P'. I guess the command was successfull when the last message on the serial console reads "Power down." This works with Legacy Images.

     

    Power consumption drops significantly. On the NEO and OPi Zero to somewhat 150 mW, NEO Air 250 mW. To my surprise the Orange Pi One drops even to 0 mW.

     

    Question 1: Why is that? Is it different voltage regulators, or are parts of some boards purposefully kept powered on?

     

    Testing Mainline Images things are more simple: I never even reach the "power down"-target, the system just halts. I tried variations of the shutdown command with no success (shutdown -P, -h, now). The SOC keeps drawing close to 1 Watt, which is in most cases more than idle.

     

    Question 2: Is there/will there be a way to power down the board in Mainline?

     

     

     

  3. I did some tests with the NEO Air in the recent days, borrowing the antenna from an OPi Zero. Since I experienced some serious lag while typing over ssh, one of the first moves was putting the thing line of sight to the router. This helped a little, but not much.

     

    Now I have been playing with iperf and several different setups. I have a second antenna that came with an OPi One. It's the same model that comes with the Zero, but seemed to double the performance. I saw a jump from 10 MBit/s to 20 MBit/s.

     

    Then I tried putting an old harddisk behind the antenna as as some sort of makeshift reflector (varying the distance as well). In one case it seemed to boost the signal, iperf went from something around 20 MBit/s to 30 MBit/s. Also, placing the HDD between the antenna and the router significantly decreased the signal.

     

    Orienting the antenna differently also had an effect. At one point performance even went down to 1 MBit/s. That's when I realised the u.FL-connector was no longer properly connected.

     

    So here is my takeaway: While they might do the job, OPi's stock antennas may vary in quality. I guess there is no quality check at the end of the assembly line. Also, it is very easy to screw up things. The consumer mindset -- plug it in in and expect it to work flawlessly -- is certainly not the right approach here.

     

    The good news is: To a certain degree you can improve things by optimizing the antenna. I see a bright future for tinfoil reflectors and cantennas. . .

    :P

     

    Boring details: There are more than 50 Wifis in the 2,4 GHz band visible at my place, so none of this qualifies as a science experiment. When using iperf, distance to the router was apr. 4 metres through air and a brick wall. Above ratios came from iperf's default mode. Reverse operation (iperf3 -R) makes roughly a +10 MBit/s difference.

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