3 replies to this topic

[ssatterthwaite]

I have a two week old or so N+2 running 4.2.2 and it worked great until this morning.  It now won't show up as a USB device even if I hold the button on power up.  The blue light is always on when I apply power either from USB or an external supply.  So I can't see it from the DFUTester app, MF Deploy, or in the device manager. I've tried 3 different USB cables with no better results.  Is there any recourse: boot from sd card, hard reset, etc?  I've rebooted my development machine (win 7 64) as well I'm fairly careful with static precautions, and I've got it mounted on a lexan board with standoffs.  The last thing I was working on was connecting to a 20x4 LCD display.  Maybe I pulled too much from the 5V on the N+2 for the backlight? Any help would be appreciated.  I have read some other posts with brick situations but I believe they were able to have some USB connectivity to recover. BTW, I've found your forums to be very helpful, and everything has been working well up until now.  I'm using mine for the basis of a beer brewing control project.  I'm using PT100 RTDs for temperature logging and am planning on running a PID controller for control. thanks! Scott

[Chris Walker]

Hi Scott, Try disconnecting everything from your board. Then reboot your PC (to make sure your USB root hub hasn't been disabled temporarily). Finally, press and hold the pushbutton while plugging it into your PC. That should make it appears as a USB device in Device Manager. That's how you get it into recovery (bootloader) mode. When you unplug it from your PC, Device Manager should show the device going away. If the blue light stays on when in bootloader mode--and also stays on when booted normally--then unfortunately it's possible that the board has been damaged. If this is the case, please PM me. You can pull quite a bit of power from Netduino Plus 2--but it does have limits. There is a fuse on the USB port to limit power but if you try to draw way too much power you could potentially damage the power circuitry. For projects with higher-current requirements--especially motor control--you will want to provide a separate power source. Beer brewing control sounds fun. Please keep us up to date with your progress! Welcome to the Netduino community, Chris

[ssatterthwaite]

Thanks for the response and welcome Chris.  You've been super helpful on this forum.

 

Unfortunately I think there is something more serious going on.  I cannot get the N+2 to show up as a USB device of any sort.  This is of course pressing the button during power on.  I have rebooted a few times; tried 3 different USB cables; all with no success.  I tried a second computer with an older Windows OS, also to no avail.  There is nothing connected to the N+2 other than the USB cable.

 

I do have access to a JTAG programmer at work.  Would it be worth it to solder in the mini JTAG?  Is there anything more I can do to debug with a scope or logic analyzer?  I had noticed that the +5V and +3V are not present at the header.  It looks like they are latched in the schematic (I assume enabled after a boot sequence).  I do see happy 5 volts at the regulator next to the micro SD slot.

 

Scott

[BobL]

See my post http://forums.netdui...d-after-deploy/