Hi Giuliano, Noom, Chris, thanks for your advice.

 

The weird thing is that after trying a bunch of times unsuccessfully, it seems to have come back alive again. With the Netduino Plus 2 plugged in, the ONLY thing I did was go into Win7 Device Manager and enable the 'Show hidden devices' option. I wanted to enable that option so that I could uninstall the driver. When I searched through the devices with that option on, nothing showed up in any of the categories. I closed the device manager and left my computer.

 

When I came back to my computer a little while later, the window for Control PanelHardware and SoundDevices and Printers happened to be open. To my surprise, I could see the Netduino Plus 2 under 'unspecified'. I thought maybe it was just to do with my 'Show hidden devices' adjustment, but then why wasn't my older Netduino Plus showing up? Sure enough the Netduino Plus 2 was back for real. I tried deploying and debugging a basic program and it seemed fine.

 

Giuliano, I really did try all the ports/cables combinations that were working for my Netduino Plus. So I have no idea why it just magically started working again. Noom, when it stopped working I was just iterating through different adjustments in software for a balance bot, I did think maybe I fried something even though I didn't see how I would have done so. Chris, when it wasn't working I did try forcing the bootloader mode with the button press but the device did not show up and the blue led did not light up.

 

Anyhow thanks everyone for the info. After the Netduino plus came back alive I was handling it wondering what the heck happened and was holding the bottom of the board and noticed it was quite warm. Currently it is plugged into USB but idle and it still seems warm. Is this normal?

 

thanks

HI spcboog,

 

Try unplugging the N+2 from your PC, then removing the driver and then plug it back in. This time make sure you select the have disk option. You have to install the MFUSB drivers for it.

 

The URL below explain how:

 

http://forums.netdui...-mfusb-drivers/

 

Hi Giuliano,

 

Thanks for the suggestion but the device is not registering at all, it's not coming up as an unknown device or anything else. If I power it up externally, the existing program doesn't seem to be running either. Is there a definitive way of telling whether the board is dead?

 

thanks

Hi all,

 

I've been using my netduino 2 plus for a couple of months without issue but yesterday when I plugged in the usb cable there was no response. 

 

The device is not registering at all. The same ports/cables work fine with my older netduino plus so I don't think it's the computer/ports/cables. The PWR led lights up, but the blue led does not light up at all.

 

Any ideas? 

 

thanks

 

Thanks Magpie, I'll try removing other elements from the overall circuit to see if it makes any difference.

Hi Magpie, Sorry about that. I'm not using ARef in my code. The two analog pins tied to ground via 800 Ohm resistors read in code ~40 with no SetRange call. If I'm not screwing up the calculation, that's ~129mV (3.3/1024*40), which is pretty far off from the multimeter reading of 1.6mV. thanks

Hi Magpie, Thanks for the suggestions. With the sensor disconnected. Vin - 9.84V 5V - ~5V 3V - ~3.3V ARef - 17.7mV AGND - 0.6mV A1 tied to ground with 800 Ohm - 1.6mV A2 tied to ground with 800 Ohm - 1.6mV thanks

Hi everyone, Pete, I tied the unused analogue pins to ground, but it didn't seem to change the results. Mario, I commented out the SetRange and for ~0.7V reading from the multimeter, AnalogInput.Read would return ~500. Since I am taking the multimeter measurements directly at the ground and analog1 pins, I am really confused about why the Read values would read so much higher. Unfortunately I don't have a trimpot. Paul, my raw analogue port reading is way too high at the maximum distance so I don't think the code is going to help until I get that sorted. thanks

Hi Mario, I don't have an ethernet cable plugged in. I tried the test using batteries only and it yields the same incorrect results. Since I'm getting expected readings from the multimeter (<1V when appropriate), is there something wrong with my code? thanks

Hi all,

I have a sharp analog infrared sensor which I'm having problems with regarding the lower voltage values (corresponding with larger distances).

- sensor is powered from 5V netduino+ pin
- Vout connected to analog 1

The datasheet states 3.1V max for Vout so this is the code:

analog.SetRange(0, 3100);
for (int i = 0; i < 60; i++)
{
   Debug.Print(analog.Read());
   Thread.Sleep(500);
}            

When the distances are small, the voltages seem to correspond with the datasheet specified values (between 2 and 3V). However when the distances are larger, the voltage doesn't seem to drop as I would have expected. I'm not really seeing anything below 1.7V or so. I tried measuring the voltage between Gnd and Analog 1 using a multimeter and the values seem to be good (below 1V when I would expect it to be). Does anyone know why analog.Read would be giving me values that are higher than what the voltage actually is?

thanks

Hi everyone, I did a bit of rewiring, replacing alot of 12" jumper wires with shorter length breadboard jumper wires. This seems to have gotten things working well enough. Magpie I didn't end up trying different frequencies for the pwm or I2C but I'll keep that in mind if it comes up again. Thanks for the advice Dan, I hope I won't have to resort to a Faraday cage for this project but who knows. It would be nice if you could buy some shielded cable sheaths though, has anyone seen anything like that? thanks

Hi Magpie, Following up on your advice, I read a bit about voltage changes induced by high current wires that aren't even part of the same circuit and one of the things they suggested was to coil/twist the high current wires around each other. I tried this (and also moved them marginally further away from the rest of the circuit) and immediately there was a difference. The gyro didn't lock up the first time but ended up reading wacky values progressively. The 2nd time it locked up still but it got alot further than usual. So it would seem to be almost definitely induced interference. I didn't have any 0.1uF capacitors to run across the motor terminals which they suggested as well. The combination of twisting the wires and keeping them further away and the caps hopefully will be enough to allow me to get this working. If not maybe I'll have to get some low current motors instead. thanks

Hi Magpie, I took your advice and tried it with and without the motors connected. The problem seems to only repro with the motors connected. The thing is, I had already disconnected the motor shield from the main battery pack (using a separate pack). With a separate power source, can the high current of the motors still cause issues? Not sure if it's relevant but the 5v logic of the motor shield is coming from the netduino since it is stacked on top of it. thanks

Hi all, I rewired so that the netduino+ and the gyro don't share any wires with the motor shield on the way back to ground (I unplugged the shield from the netduino+). Unfortunately it still doesn't work. Maybe even with this wiring configuration, the voltage to the netduino is not reliable enough when the motor controller shield is involved. I tried using a 10uF capacitor at various power/ground connections but that didn't seem to fix things. To get around the problem for now, I'm going power the motor controller shield with a separate battery pack. This isn't great but I want to get on with the project in the meantime. Going back to the single battery pack configuration, do you guys think that perhaps powering the netduino+ from a separate voltage regulator might work? So in other words: 1 Battery pack which powers 2 separate regulators: - 1 5V voltage regulator which powers - motor shield - servos x 2 - parallax ping - 1 7.5V voltage regulator which powers - netduino+ thanks

Thanks everyone for the tips.

After reading Hanzibal's suggestion, I tried a 10uF capacitor between the power line and the ground line of the gyro but that didn't seem to work. I only had the 1 cap so I couldn't try a different capacity cap.

Magpie, I am using the pwm pins for the motor controller and the I2C pins for the gyro so I don't think that I've got a problem there.

When I disconnect the motor controller entirely but still drive the PWM pins, there doesn't seem to be a problem. So perhaps as Mario said, there's a problem in the wiring.

My setup is:
- a 6xAA battery pack which is split between:
- Vin/Gnd on netduino+
- Vin/Gnd on a 5V (3A) voltage regulator

- the output of the 5V voltage regulator is split into
- the power input of the motor controller shield which drives 2 motors
- the power input of 2 x micro servos for a pan and tilt bracket
- the power input of a parallax ping sensor

- an I2C ITG3200 gyro which is powered from the 3v3 from the netduino+ (and connected to a netduino+ Gnd)

I'm not sure if it's possible but I'm going to try and wire it up in such a way as to resemble Mario's 2nd diagram.

I also was wondering whether I'd be better off getting a serial to PWM controller to generate the PWM signals but if it's a wiring issue then I'd probably see the same thing anyhow.

thanks

Hi all, Hopefully someone can shed some light on this: - Reading from an ITG3200 gyro via IC2 works fine by itself - As soon I starting using PWM to drive a motorshield the reads on the ITG3200 lock up (never return) The motorshield is externally powered. Thanks