I want to test a Atmega chip at 8Mhz. I have an Sparkfun Red board which is a clone of the Arduino Uno R3 which runs at 16Mhz. Can a Arduino Uno R3 at 16Mhz be configured internally at 8Mhz? Thank you in advance.
Yigiter007: I want to test a Atmega chip at 8Mhz. I have an Sparkfun Red board which is a clone of the Arduino Uno R3 which runs at 16Mhz. Can a Arduino Uno R3 at 16Mhz be configured internally at 8Mhz? Thank you in advance.
In principle yes, but why do you need this? I built an Arduino on a Breadoard (minimalistic approach). Due to lack of a crystal I found out that I can make use the internal PLL at 8 MHz. My main usage is TinySP for all my Attiny experiments.
See Minimal Circuit at http://arduino.cc/en/Tutorial/ArduinoToBreadboard
I want to use a arduino pro mini. The 8Mhz one has a lower voltage and negates the need for a voltage booster with LiPo batteries and the 8Mhz means it will draw less watts from the battery because it’s doing less processes which will extend the battery life.
Yes, you can re-program the bootloader and fuses to operate the Uno from the internal 8 MHz oscillator. You need another Arduino "as ISP" or an ISPASP to do this.
Could be simpler to buy the Pro Mini of course,
I just want to know the limitations of a Atmega328 at 8Mhz versus 16Mhz. Like what is an example of a component or process that can’t be done on a 8Mhz that requires 16Mhz. Maybe GPS or data logging or video processing. I haven’t had much experience with all the possible components, since I recently started and only done a select things with the Arduino. .
Yigiter007: Maybe GPS or data logging or video processing.
GPS is of course, trivial as all the processing is performed in the GPS module itself.
Arduinos - or at least the ATmega part of them - do not do video processing though at 16 MHz (minimum) people have been able to generate "classic" video-game style animation.
it is not necessary buy a promini or reprogram the fuses on uno. simply writing a byte to the prescale register will cut the 10mhz clock to 8mhz. also note that for most applications a 16mhz promini runs fine off 3.3v or 1 cell lithium.