How does this no-crystal thing work? Essentially, we are simply going to run the 16MHz Atmel328P at 8MHz-ish (RC oscillators are not as accurate as crystals) and the Arduino programming environment will set all the timing constants at compile time. This means that such things as tone() will continue to work at the correct frequency as with functions such as millis(). To make this magic happen, we need to provide the Arduino environment with some information about our new hardware configuration. Such information is provide to the client Arduino software on your PC/Mac/Linux box via a file named boards.txt. The following article explains how to install the file:http://arduino.cc/en/Tutorial/ArduinoToBreadboard please refer to the section titled: Minimal Circuit (Eliminating the External Clock) The screen-capture of the settings used by the 8MHz RC fuse configuration is shown in the second graphic.The no crystal approach may be a great way to save a few cents on your next barebones project or lower the power requirements for battery operated projects. Most things will work OK with the lower frequency; however, please remember that timing-critical stuff such as serial communications to the PC or other devices (say, reading a GPS) are likely NOT the proper place to save the price of a crystal. That being said, you may still wish to consider the lowering of the standard 16MHz frequency to a lower crystal frequency of 8MHz to lower the power requirements.
My Opinion:Barebone <anything> is simply not for those without sufficient experience with the non-bare product(s). Even for us old timers, it can be stressful getting such projects to perform.There is simply not enough $aving$ to warrant going this route. I have 3 such projects on my bench right now - but, I'm designing small singke-purpose chips to frontend signal processing for a downstream Mega2560.- Ray
Barebone <anything> is simply not for those without sufficient experience with the non-bare product(s).
I used a redboard bootloader.
QuoteBarebone <anything> is simply not for those without sufficient experience with the non-bare product(s).Yeah, it's a bit frustrating to watch all of the people having problems, without having much to say that will help. This is what using microcontrollers was like without Arduino (or the equivalents like Basic Stamps.) Avoiding this sort of thing is why those are such wonderful products!QuoteI used a redboard bootloader.So... I give up. What's a "redboard bootloader"? The sparkfun Redboard kit(s), which I assume is what you're talking about, says it uses an ATmega328 with the Optiboot bootloader. How did you program the bootloader? If you're not seeing ANY activity on pin13, then the bootloader burn was not successful. (It should blink rapidly several times after reset.) Optiboot, together with the normal ways to burn it, does need the crystal. The instructable you reference talks about using the Lilypad bootloader that uses the internal oscillator. But there were several versions of the Lilypad, and the newer ones use an external crystal (an 8MHz one, to be compatible with the lower supply voltages.) What are you doing for reset? The optiboot bootload process requires an external reset; mere powerup won't do the right things. You said you progammed blink. How? What do you have the "Board" set to for loading the sketch? What was it set to for burning the bootloader? What are you using for the serial connection?Or did you mean that you programmed the chip when it was in your redboard, and have taken it out and are trying to get it (the already loaded sketch) running on the protoboard? That should work, but it will require the crystal as well.
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