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[on:]

Greetings all and Happy Holidays !!

I have purchased a bare bones Arduino kit from Jameco.com.  Their listing can be found here: http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2151259_-1.  Instructiions were not included with the product.  Instead one has to look elsewhere for instructions.  They are found here: www.jameco.com/arduinobuild.

I have tried to assemble this kit on a breadboard and I'm not successful.  It seems to me there are some things that are not being explained clearly in their instructions.  Also, I have modified the setups on the voltage regulators to remove a lot of clutter from the breadboard, while keeping the necessary components, and basically make the regulators "plug-and-play components" for any breadboard application.  The regulators are working with this configuration.

Photos of my setup can be found here: http://grpace.net/arduino/photos/breadboard/.  There are views from the front, top and back of the setup.  Front view...  On the left is the LM7805T.. on the right is the LM1117T.

I took the processor from this kit and swapped it with the processor on the Uno, burned the boot loader to the chip, and downloaded the "Blink" example to the processor.  On the Uno, it works as expected.  However, when moving the processor back to the breadboard, nothing happens.  I moved the processor back to the Uno (in case the breadboard circuit burned the processor), and it works.

This tells me there's something wrong with the breadboard circuit.  The only modifications I have made to their instructions have only been to clean the breadboard up a bit, as their's was a jumbled mess.  On the oscillator, I have also bent its legs to fit neatly on pins 9,10, instead of being at an angle like their instructions.

Could someone more knowledgable than myself please take some time to review their instructions and my setup and pin-point exactly what is wrong ??  

Any help is GREATLY appreciated.

Thank you!
grpace

[Reply #1 on:]

The bare minimum really is the just the chip + crystal.

Power it with some batteries and it should work.

You can build the rest up from there.

I would start by checking if the mcu gets power; if it is out of reset; if the oscillator is working, etc. and back to the regulators, etc.

BTW, always remember this: we are too poor to buy cheap stuff.

[Reply #2 on:]

Hi again, dhenry!  Thank you for your reply!

I would start by checking if the mcu gets power; if it is out of reset; if the oscillator is working, etc. and back to the regulators, etc.

The processor is getting power... Rechargable 9-volt battery at 8.88v.  Power at pins 20 & 21 fluctuates between 4.95-4.97 volts.
How can I tell if the oscillator is working ??  I have been suspect of this.  With a pair of tweezers...  just barely touching the oscillator... the top moves quite freely...  It doesn't appear stable.  How can I test the oscillator??  I don't have a scope.

[Reply #3 on:]

I have done a breadboard Arduino as well and I had trouble with it until I put a 10uF and some decoupling caps close to the IC. All of your caps are way back on the regulator. It is hard to see from your pics but I think your LED might be wired wrong. It appears from the pic that both cathode and anode and the resistor are all in the same column. To check if the Arduino is working I would get voltmeter and see if you can see pin 13 voltage go up and down. If you can see the voltage rise and fall then you know it works and you just need to fix the LED wiring.

[Reply #4 on:]

Definitely the LED. You need to use two separate rows of your breadboard for the two pins of the LED. How were you able to get the crystal to fit on the two adjacent rows?

[Reply #5 on:]

As liudr says, you have the LED wired incorrectly, the breadboard is shorting it out. I'm also suspicious of the capacitors connected to the crystal because they look fatter than 18pF or 22pF capacitors usually do. Are you sure they are of the correct value?

[Reply #6 on:]

The pins you care about are Vcc vs. GND (pin 7 vs. 8/22). You should see ~5v.

For the oscillator, put your multimeter on OSC2 and you should see a fluctuating voltage at around 1/3 - 1/2 of Vcc. You can also probe OSC1 - sometimes that helps getting the crystal going.

You can also build a RF probe: a capacitor + a diode (1n4148 or even a small led) + (resistor // capacitor) to ground. Put the cap's one end to OSC2, and you should get a small voltage (100mv - 500mv) on the resistor // capacitor.

Also, don't forget to check your wiring.

[Reply #7 on:]

Thanks to all of you for the help.

It absolutely was the LED getting shorted.  I don't know why I didn't realize that...  It was right there staring me in the face !!

All is working, now.
Again, thanks to all of you !!

[Reply #8 on:]

Thanks again to all that solved this question for me.

However, I have a different question regarding the build of these kits:
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2151259_-1
Instructions at: http://www.jameco.com/Jameco/workshop/JamecoBuilds/arduinocircuit.html?CID=arduinobuild

The question involves Step 3 of the instructions.  They state:
Pin 20 needs to be connected to power if ADC isn't being used, and if it is, it needs to be connected to power via a low-pass filter. (A low-pass filter is a circuit that lessens noise from the power source).

I can't imagine not wanting the ADC functionality.  However, no components are included in the kit for this low-pass filter that's referred to, no indication of what components are necessary, OR how to connect them !!

Could someone please share some insight on this ??

Thanks in advance.
Greg