Xbee + Arduino wireless reset not working…

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tterragcnoom
 
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Xbee + Arduino wireless reset not working…

Post by tterragcnoom »

Hello all,

I'm following the tutorial here: http://www.ladyada.net/make/xbee/arduino.html attempting to wirelessly program my arduino.

I seem to have gotten everything to work except the reset circuit – it doesn't work. I can get firmware to upload if I reset the arduino manually. I also have the pin out on the XBee working. It's high until I start the firmware process and it's pulled low. However I can't get the transistor to open up (if that's the proper terminology). For the record I don't know much about EE, just the bare minimum. I've tried changing the resistor and capacitor values and even removing them. The transistor doesn't seem blown from testing with a multimeter. I have everything running on 3.3v if that makes a difference. I imagine I must just be using the wrong values? How do I figure out what values to use.

Also, if someone would be so kind as to explain the reset circuit? I really don't understand how it works. Explaining each and every part would be a godsend.

Thanks a bunch in advance!

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Re: Xbee + Arduino wireless reset not working…

Post by adafruit »

its almost certainly a wiring problem
are you SURE You have the right model of transistor?
if you post a nice clear photo of your set up i will probably be able to debug it

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tterragcnoom
 
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Re: Xbee + Arduino wireless reset not working…

Post by tterragcnoom »

Thanks!

Part of it appears to have been the transistor, I didn't realize that it mattered beyond being npn or pnp (I'm very new to this). The capacitor I'm using says 104 on it, that means it's 0.1µF, right? I've also tried a .01µF capacitor. The circuit diagram shows a capacitor with polarity. I'm don't even know how to see if my capacitor has polarity… they have the same length legs. I'm using a 10k resistor (I know how to figure that out!).

Anyway, it now resets the arduino, but only after avrdude has failed. I assume this has something to do with the capacitor… It seems to hold the reset pin low for the entire time avrdude is trying…

Would you be willing to explain the circuit to me? It would be immensely helpful. I have several books, but they don't really seem to deal with the subject in a way I understand…

Here are some pictures of my setup: Sorry they're awful blurry

Image
Image

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Re: Xbee + Arduino wireless reset not working…

Post by adafruit »

your photos are way too blurry to be useful. if you want me to spend some time helping you, it would be nice if you could spend some time to at least take a good photo. :P

the circuit is a transistor inverter with a blocking capacitor

nearly all transistors have different pinouts

to properly 'teach you everything about the circuit' would take about 2 months
if you want, spend a bunch of time on google and wikipedia to learn about transistors and capacitors
if i explained the circuit, that would STILL mean you need help fixing it and i have limited time.

if you tell me WHAT transistor you have AND take a good photo, i might be able to help.

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tterragcnoom
 
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Re: Xbee + Arduino wireless reset not working…

Post by tterragcnoom »

Sorry if my request seemed rude, that wasn't my intent, I really appreciate your help.

I've tried to get a better picture, it's still blurry, but at least bigger. The leg of the capacitor that you can't see is attached to the same strip as DIO3 (the other is attached to the base). The transistor I'm using says:

2N
2222
A338

img: http://img200.imageshack.us/i/img1556r.jpg/

I got it out of a radioshack grab bag of NPN transistors.

Thank you so much for your help. I realize I'm working on a ridiculously ambitious project for a software engineer without any EE knowledge.

A preface to these questions, they're asked with reverence and out of ignorance:
Would a triac work here? Would the voltage on the reset pin drop when the arduino's reset and therefor open the triac back up?

Thanks again,

-Garrett

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Re: Xbee + Arduino wireless reset not working…

Post by adafruit »

ah yes
2n2222
i believe its CBE not EBC
so flip the transistor around

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tterragcnoom
 
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Re: Xbee + Arduino wireless reset not working…

Post by tterragcnoom »

I flipped the transistor and I get the exact same behavior (now that's weird). Any other ideas? By the way, I believe the transistor was correct the first time based on the confusing diagram I have on the radioshack bag.

Could it have something to do with avrdude? It seems to keep the RTS pin low for the entire session. Is the capacitor supposed to stop this? Thanks again for your help,

-Garrett

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Re: Xbee + Arduino wireless reset not working…

Post by adafruit »

use x-ctu's terminal with the "set clear RTS" button to test that RTS is able to reset
also make sure you have "SET RTS ON CLOSE"
which is in the tutorial
of course, my tutorials are for the adafruit stuff, not sure if it works with sparkfun's adapter for who knows what reason.

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tterragcnoom
 
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Re: Xbee + Arduino wireless reset not working…

Post by tterragcnoom »

Using the X-CTU I'm able to see that the reset happens nearly instantly, unlike with avrdude which waits about 10 seconds, fails and then lets RTS go up again. I'm not using windows to operate avrdude, I'm on a mac (it mentions in your tutorial that the set RTS on close isn't necessary for mac and linux). Thanks for any more help, I know that you're being generous with your time and not supporting a product you sold.

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Re: Xbee + Arduino wireless reset not working…

Post by adafruit »

sorry, im just too busy with adafruit customer support i have to stop working on this thread. the tutorial works, if you spend the time to follow it and have proper tools like multimeters and oscope you will be able to get it to work.

dluther
 
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Re: Xbee + Arduino wireless reset not working…

Post by dluther »

I am seeing the same occurrence, with the reset being held low for almost 10 seconds, with my adafruit xbee adapters. Have you had any luck in solving this problem?

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