Yunx
Posts: 2
Joined: Mon Oct 28, 2013 1:29 pm

After rebooting, Arduino Nano that connects to RPi not found

Mon Oct 28, 2013 1:44 pm

I connect Raspberry Pi with Arduino Nano V3 via a micro USB cable, and I am able to exchange data between them via PySerial (http://www.raspberrypi.org/phpBB3/viewt ... 32&t=38360).

However if I reboot Raspberry Pi (with the Arduino Nano connected on the USB port), the serial device for Arduino is not detected by RPi (the serial port of Arduino is not listed when executing "ls /dev/tty*" command in console). It seems that Arduino boots faster than Raspberry Pi, and RPi missed the first chance to talk to it. I reset Arduino several times (by clicking the reset button on Arduino board), but that doesn't help. The only way to let RPi recognize the Arduino is to unplug the Arduino and plug in again.

I really don't want to repeat the unplug/plug steps after every reboot of Raspberry Pi. I wonder if someone have ever met this kind of issue, and if there is any workaround for it? Thanks in advance.

Michelle10
Posts: 3
Joined: Fri Aug 30, 2013 5:50 pm

Re: After rebooting, Arduino Nano that connects to RPi not f

Wed Oct 30, 2013 8:48 pm

Just an idea- is your Arduino powered directly off your RPi, or via a powered USB hub or its own power source? The Arduinos can be pretty fiddly when powered off of the RPi. I assume you're looking for both the common ports (/dev/ttyACM0 and /dev/ttyACM1). Mine often switches ports after unplugging or rebooting.

Yunx
Posts: 2
Joined: Mon Oct 28, 2013 1:29 pm

Re: After rebooting, Arduino Nano that connects to RPi not f

Fri Nov 01, 2013 9:59 am

Hi Michelle,

Thanks for the idea, and I think you are pointing to the correct direction. Yes I powered Arduino Nano via the USB port on RPi, and now I guess that's the problem.

If I unplug the Arduino and boot RPi, then plug in Arduino after about 0.5 second delay, everything works just fine after RPi finishing the boot. So it seems that booting RPi with Arduino connected draws too much current and Arduino can not boot successfully.

However even I used a powered USB hub (1A), it still does not work. I will find a USB hub that can give 2A current and try again.

BTW, my Arduino Nano is displayed as /dev/ttyUSB0, sometimes the 0 could be replaced by 1, 2, 3...

Resonant1
Posts: 3
Joined: Thu Sep 19, 2013 1:14 am

Re: After rebooting, Arduino Nano that connects to RPi not f

Mon Nov 18, 2013 2:41 am

Hello All,

I am having the same problem even when the Nano is connected to a powered USB hub. If the Nano doesn't power up after the PI, it doesn't detect. Is there any kind of reboot with the USB port that would solve this?

Cheers,
Craig

achrn
Posts: 376
Joined: Wed Feb 13, 2013 1:22 pm

Re: After rebooting, Arduino Nano that connects to RPi not f

Mon Nov 18, 2013 8:31 am

It's a hardware bug on the nano board.

At least, it always has been for me. Is it more reliable if you just plug the nano in without any circuitry connected to the nano?

The nano uses a DS_FT232RL for usb (chip on the bottom). If you look at the data sheet http://www.ftdichip.com/Support/Documen ... FT232R.pdf you will find that pin 26 is 'Test' - "Puts the device into IC test mode. Must be tied to GND for normal operation, otherwise the device will appear to fail." I expect you might see where this is heading already...

If you look at the nano schematic http://arduino.cc/en/uploads/Main/Ardui ... ematic.pdf pin 26 on the FT232RL is ... disconnected.

However, you will notice that pin 25 is connected to ground on the nano. So a solder bridge between pin 25 and pin 26 will solve your problems. At least, it has solved all of mine (ok, maybe not all, all the ones with USB on an arduino nano though).

You want a solder blob between pins 25 and 26, being the fourth and third down on the right hand side when you look at the chip with the dot at top left. Obviously, you don't want to short the adjacent pins into this blob. Good luck. Alternatively, if you look further up the board you can see a reasonable expanse of ground plane in the traces, and notice that the top end of the right SMD component just above the chip is connected to that. You could put a flying wire from pin 26 to the top end of that component. I think the solder bridge between legs is easier.

I'm assuming you have a V3 nano. That's all I've ever used.

Edit: I believe Gravitech have fixed their own 'genuine' boards. I believe there are an awful lot of half-the-price chinese duplicates that aren't fixed. I've only ever bought cheap clones, and the boards I have all show the same problem.

Resonant1
Posts: 3
Joined: Thu Sep 19, 2013 1:14 am

Re: After rebooting, Arduino Nano that connects to RPi not f

Mon Nov 18, 2013 11:32 pm

Awesome. Thanks for the thorough description. I had ruled it down to a Nano problem (although not the why) when I replaced it with an Arduino Micro running the same exact setup and it works fine after a power up.

Thanks again for the info. Now I can mod the Nano to work on my other Pi project!

riker1
Posts: 11
Joined: Tue Jan 31, 2017 5:10 pm

Re: After rebooting, Arduino Nano that connects to RPi not f

Tue Apr 11, 2017 5:58 pm

Hi
this is strangewise not working for mine.
Soldered 25 and 26, but not recognized on Pi2 und Pi3 at startup or boot. only hotplug in .

But it is working on a Pi 1.

Do not have a glue why?

Thanks for hints.

Thomas

Roger_Brownstone
Posts: 14
Joined: Tue Nov 01, 2016 8:05 pm

Re: After rebooting, Arduino Nano that connects to RPi not f

Thu Jul 06, 2017 5:04 pm

Dear Riker1,
I am having this problem. I have not got the answer (don't you just hate that?) but my investigations might help your observations
If your Nano is a relatively new one it will not be that problem. The original writer correctly sited the V3.0 PCB as having the problem. By 2014 (maybe earlier) V3.2 had this problem solved with the pin grounded
My (new) Nano is a V3.3, so has the pin to GND but still does not work on my Pi B+
Interestingly, the same Nano works fine on my PC (32bit W7) but not on the Pi (powered separately to avoid current drain). The Pi can see it and I think I have actually programmed it on the Pi but when it comes to looking at the serial monitor on the Arduino IDE it makes about 2 readings of the sensor about 5 minutes apart then croaks (Arduino IDE freezes. Restart Pi). My Python program can see the USB port but gets no useful data from Nano

I have spent many hours looking for a solution to no avail. My Uno works fine and one of the other contributors said a Micro works. I think that is the way to go

noccy
Posts: 1
Joined: Thu Dec 28, 2017 5:31 pm

Re: After rebooting, Arduino Nano that connects to RPi not found

Thu Dec 28, 2017 5:38 pm

Did anyone ever come up with a solution to this? I have a RPi 3 running Node Red, and an Arduino Nano running Firmata as I/O extender. Right now I have to manually pull and plug the USB-cable for the Nano to come alive after a reboot, which isn't really great for reliability :roll:

gdschut
Posts: 1
Joined: Sun Mar 17, 2019 3:40 pm

Re: After rebooting, Arduino Nano that connects to RPi not found

Sun Mar 17, 2019 3:43 pm

I solved this by using a cheap Chinese Arduino Nano V3.0 with a CH340 chipset.

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