Can someone let me know what type of oscilator is installed on the arduino nano?
Is it a crystal or a ressonator?
This is the one similar to the mini, without the USB port.
I have an error of 1Hz for every KHz, so I wanted to know if this is down to the clock source or not, so I could decide whenever to use an atmega328 with a crystal or just calibrate the clock.
There is a resonator. Just look at the product picture. It is the same resonator type as e.g. UNO R3 has - pretty unaccurate - good for kitchen timer.
Yes, its the same as the new Uno with the Atmel for RS-232 conversion. I was in the doubt.
So whats the closest thing one can do to put a crystal here?
Regards
Yes, for better clock accuracy full swing crystal has to be used, but depending on your needs, e.g. if your circuit sholud keep the time
is better to use RTC which wil be independent on system clock, because crystals have also some tollerance and are liable to wearing. It could not be acceptable for time mesurement or doing something accurate at kHz for long period.
Budvar10:
Yes, for better clock accuracy full swing crystal has to be used, but depending on your needs, e.g. if your circuit sholud keep the time
is better to use RTC which wil be independent on system clock, because crystals have also some tollerance and are liable to wearing. It could not be acceptable for time mesurement or doing something accurate at kHz for long period.
Thanks,
I need accurate system clock, not time
What I meant with my question was if someone knows with a crystal that is size squivalent to the ressonator on the boards.
Adding a standard crystal do a uno may be doable, but it would be a challenge on a nano
I have just verified this issue.
The ressonator on the Uno Reads 15.953M, while the crystal on the mega16u2 (TTL to USB, same board) reads 15.999M.
Not a lot, but certainly explains the error I was having on my code.
Its Ridiculous that we can get better specs with non official hardware, for the sake of a few pences on a crystal and 2 capacitors.
This is the one similar to the mini, without the USB port.
Nano has a USB port tho - so what board are you actually talking about?
Or are you referring to the Promini as not having the USB port?
CrossRoads:
Or are you referring to the Promini as not having the USB port?
You are right its the Arduino pro mini. Always confuse them.
http://www.arduino.cc/en/Main/ArduinoBoardProMini
But all the newer arduinos come with the same oscillator, even the due - Thats what I find hard to understand.
I'm up to look for a decent arduino board for development. One with jumpers to select outputs to LED's, perhaps a built in potentiometer. Is there such a thing? I hate all the messy wiring, might as well put an atmega328 on a breadboard 
Doesn't Esplora have somethings built like that?
CrossRoads:
Doesn't Esplora have somethings built like that?
http://www.lifehacker.com.au/2012/12/the-arduino-esplora-is-an-open-source-controller-packed-with-inputs/
Not quite what I am looking for.
I am looking at something without acessories, BUT with conectors for the SPI, I2C, Serial, perhaps an LCD port available in a simple to use header along with supply I could just plug a molex plug into to add accessories, for example, or leave unused, depending on my work. (besides the normal I/Os the arduino can provide.
Also adjustable voltage (3.3 or 5V) and LED's to monitor input and output (I could use a jumper to disable them, for example to read an ADC), one or two potenciometers a few switches and a RC filter for PWM to analog conversion would be most welcome.
If you look at it, even the format of the arduino itself is not breadboard friendly. Sure we can get the shields, but for quick prototyping its a waste of time and a mess of wires.
There are many boards that have signal, power, gnd for each pin. I added that capability to this board, and made the headers for D0-D7 and D8-D13/etc 0.1" pitch protoboard compatible.
Nice thing about Atmega1284P is that 32 IO are available, with dual hardware serial ports.
http://www.crossroadsfencing.com/BobuinoRev17/
Screw terminals are an option:
I am not such a great fan of screw terminals, But I love the fact that you can actually plug a shield and have the remaining pins available.
Resetable fuse is nice as well. Whats the CR2032 Battery socket for? RTC?
I actually didnt knew the atmega 1284 could be used with the arduino? I actually have a 644 and a 324 with me.
Any modified bootloader?
What are the main differences, other than more memory and pins?
Battery is for DS1307 RTC.
Yes, 1284 plays nice with Arduino.
More memory than 328P (128K), 32 IO, dual hardware serial ports, more SRAM than 2560 (16K). And still available in DIP.
(324, 644, less memory, only 1 hardware serial depending on the part, review the datasheet)
See here for bootloader, IDE files to add to /variants folder.
Update boards.txt for smaller memory sizes as needed.
My boards use Bobuino for pin mapping, so Serial is still D0/D1, SPI is still D10-11-12-13
http://forum.arduino.cc/index.php?topic=235521
CrossRoads:
Battery is for DS1307 RTC.
Yes, 1284 plays nice with Arduino.
More memory than 328P (128K), 32 IO, dual hardware serial ports, more SRAM than 2560 (16K). And still available in DIP.
(324, 644, less memory, only 1 hardware serial depending on the part, review the datasheet)
See here for bootloader, IDE files to add to /variants folder.
Update boards.txt for smaller memory sizes as needed.
My boards use Bobuino for pin mapping, so Serial is still D0/D1, SPI is still D10-11-12-13
Updating the mighty-1284p core - Microcontrollers - Arduino Forum
Brilliant Stuff CrossRoads.
2 Serial ports in DIP format is quite atractive for some of my projects.
BTW the SPI code on the other topic worked fantastically.
Regards
Cool. I like SPI, great way to send data out.
