arox

Well, in french we use to say "Tomber en marche" for such problems. It is a computer scientist joke. It means that a software bug is no longer occuring and we don't know why. Connectors and PSU are more or less crappy and wires too thin. Multimeters cannot show peak amperage demands. Boards (software and hardware) and accessories generate unpredictables peak loads so fiddleling with cables is often sufficient to crash the board some time later or on reboot. Is there a software or hardware solution to trace (and record !) power failures before the system crash ?

700 mW for a single device with its own PSU is good : small 5V PSU typically are rated 0.3 W consumption without any load and max 70% efficiency (only when power demand is near nominal power). Those who want to build a cluster (or a group of devices) should also invest in a good PSU to power the whole cluster + disk + hubs + goodies at around 80% of nominal power.

tkaiser said : "For RPi Zero exactly zero use cases come to my mind" Well, I have an old Raspi A that serve a dozen of relays, IR transmitter, buzzer, Bluetooth remote, and other goodies. A 80286 would do the job. Idem with an other Pi for a waker (lamp + buzzer + radio), and other for temp sensors ... So my personal use cases are low power, low consumption devices in a BT pan network. Ideally, I should use aduinos and mesh zigbee or z-wave network, but it would cost much more time and money ! So I am very interested in nanopi neo as RPI zero is so hard to find. Thanks for your work. Even if you dont have use cases for some cards, other will have the needs that match the specs. (I dont use a computer anymore but a network of arm nodes with specific roles : server, fw, desktop ...)

Well I interconnect 2 Pis uart in order to get serial console with 3.3V lines. Cheap and simple. With sometimes curious side effect : power led glowing without power supply on bpiM2+ (powered by uart !) or boot fail on monitoring BPI when bpiM2+ crashed in unknown state during boot ... N.B. On bpiM2+ tx/rx order is inverted in comparison of RPI or bpiM1.

"This will correctly set RTS line, I believe and following hciattach won't fail anymore." The echo command blocked when I tried yesterday. All the same, it can certainly be fix by workaround, patch for bcm43xx or uboot init params. But I am stuck on bnep problem : the kernel seems to create a bad bnep interface that cannot be bridged nor configured (that is while the pan link is dropped immediately). Is there firmware patchs available ?

@dony71 Yes, I can pair with clients. But I cannot establish pan connection with internal controler (I can do it with external usb). Bluetooth report bnep protocol and nap profile via sdp, it register service locally, but bridging fail - it seems that in fact the creation of bnep interface silently fail. N.B. I have done a lot of thing : recompiled bluez, removed systemd, but I think bnep creation is a bug (one more) in bluez or configuration problem. And I always have to do hciattach 2 times before it download firmware.

I have a CSR usr Bluetooth dongle but it is not usable on my bpiM2+ with kernel 3.4.112-sun8i. I can make bluetoothd reconize my TWO controlers ONLY so : * copy firmware to /etc/firmware/ap6212/4343A0.hcd * stop bluetooth (and unload btusb used by by CSR dongle) * unblock rfkill * init bcm43xx with hciattach (first try fail on timeout but seems to enable correct registration of CSR USB dongle) * 2nd init with hciattach which load firmware * bring up interfaces and reload btusb something like this : rmmod btusb /etc/init.d/bluetooth stop rfkill unblock all hciattach -t 1 /dev/ttyS1 bcm43xx 115200 hciattach -t 5 /dev/ttyS1 bcm43xx 115200 hciconfig hci0 up modprobe btusb hciconfig hci1 up If I dont do that, bluetoothd complains : localhost bluetoothd[457]: Failed to read info for index 65535: Invalid Index (0x11) and I cannot even use CSR USB dongle.

I try to use a CSR bt dongle on bpi m2+ but I cannot make it register by bluetoothd : hciconfig show hci0 device, I can make it discover by another bt host, but bluetoothctl does not see it. When it start, bluetoothd complains with the following message in daemon.log : localhost bluetoothd[3278]: Failed to read info for index 65535: Invalid Index (0x11) (Error comes from adaptor.c in bluez source) If I unload bcmdhd module bcmdhd , error change to : localhost bluetoothd[3373]: Failed to read info for index 16: Invalid Index (0x11) rfkill list also sunxi-bt device but I don't know how to disable it and I Cannot find in kernel config an option to buid or not a driver for on board bt. Is it a mess in drivers or a bug in bluez5 ? (forums already mention such problems but without any response as usual with bluez bugs - they suggest endian pb - recompiled bluez with no change ...) (My kernel is the last one with patch for enabling g_ether)

@Xer0 "no network cable" Perhaps is it true ? I've got a lot of USB-A micro USB cables, but half of them come from PSU and only wire V+ and GND ...

OK Your kernel works for my BPI m2+ PCB rev 1.1 I get g_ether loading and link detect, so I manage to make IP over USB : 121 Mbits/sec. Power threw gpio or jack is always erratic so far. Dupont connectors can be blamed but I soldered (big) wires on jack input on the PCB and add a huge capacitor with a 2 amps PSU and still got inconsistant results (reboot, fail to read .verbose ...) ?!? BTW what about g_ether on A20/bpi M1. Does it really need 4.4 kernel ? (I can spare 1 bt dongle, 1 ethernet switch and 1 usb to eth adaptor with that)

tkaiser : "Do you have a v1.0 or v1.1 PCB revision?" Brand new v1.1 from reichelt.

tkaiser said : " I then replaced the PSU with another one where barrel plug fitted somewhat tighter and subsequent boots were fine. Maybe that's the culprit?" I use to power my RPI threw GPIO. I never tried with BPI. I dont have the schematics for BPI M2+. (On RPI it shunts the fuse). I will try to add a capacitor (the PSUs can have bad noise level) and power threw GPIO. I'll tell you if my BPI survive ...

tkaiser said : "But that's a basic requirement to interconnect g_ether attached devices: Bridging between the individual USB network interfaces at the host (you can also try to solve this problem on layer 3 and above -- TCP/IP -- but you will get lost in routing and mad for sure)." I use proxy arp to do level 3 transparent routing without any need to maintain routing tables (The concentrating host reply for arp requests for attached devices). (e. g. /usr/sbin/arp -i eth0 -Ds 192.168.1.194 eth0 pub). You just need to subnet attached devices with a few more bits, enable routing on your concentrating host and make it default router on attached hosts. I already do it with pan (bluetooth bnep) networking to use PIs as IOT solutions. I have got a bpi m2+ a few days ago for the eMMC. I wanted to use it as desktop but stopped test when I found out that it could not handle 4:3 video mode out of the box. So I will try to use it in replacement of a rpi 1 as firewall+proxy+gateway+wifi/bt-AP that need storage for cache. The possibility to interconnect my 2 bpi M1 and my new M2plus is important for me, so I am looking for having ip over usb desperately on bpi M1 and bpi M2+. Btw I have a problem : my new bpi M2+ don't boot when powered threw jack ?!? It seems to hang when initializing disp or just before. (No drop on voltage mesured on gpio). So I must at present power it threw micro-usb and cannot test plug in and out. I compliled g_ether with igor modif 'static u8 is_udc_enable = 1;' yesterday, could not configure it as module, got usb0 interface but no device detection at other end (with usbnet and cdc_ether) ? I will try your kernel asap.