Please Help me choose the right Arduino

Discussion in 'General Electronics Chat' started by RodneyB, Jun 26, 2015.

  1. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
    633
    13
    I would like to start using the Arduino

    I would like some advice on which unit to buy and the other equipment that goes with it.
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,647
    2,346
  3. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
    633
    13
    Thank you for the advice and help. What Confuses me a little is what processors or IC's are used in the Arduino. Is this similar to A PIC microprocessor. Once you program the chip you take it out and build it permanently into your circuit.?
     
  4. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    2,802
    832
    The Arduino is programmed on board. It is like the scenario you describe. Once the Arduino is programmed, the sketch (what Arduino calls its program) remains until another sketch is loaded onto the board.

    Various processors are used, depending on the Arduino variant. That's what gives each board varying amount of processing power and I/O. For example, an Arduino Uno (a popular board) has an ATmega328P processor on board. These processors are from the ATmel AVR family.

    For the most part, you don't have to be concerned with what processor is inside. What is important is the specifications of the Arduino. The Arduino is a platform - which takes many of the concerns about using a stand alone processor moot. However, it should be considered a stepping stone, if more than one simple project can be seen in your future.
     
    Last edited: Jun 26, 2015
    RodneyB likes this.
  5. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,387
    497
    Get Uno.
     
    RodneyB and tjohnson like this.
  6. flat5

    Active Member

    Nov 13, 2008
    403
    17
    Uno supports 32k flash and 2k ram.
    Mega 256k flash and 8k ram.
    The Chinese boards are so inexpensive you can play with both but to start, yes, get the Uno r3.
    Cost less than $5.
     
  7. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
    633
    13
    One thing I still don't understand,

    Once I have built a project and want to make it permanent do I buy a ATMEGA328P-PU and then program the software into it and build it on a separate board.

    They seem to be very expensive and what if you don't need as many inputs and outputs? I just cant seem to find the answer.
     
  8. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    Yes, that is the way. And yes, they are expensive. For a less expensive alternative, consider PICAXE microcontrollers. www.picaxe.com
     
  9. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    2,802
    832
    IMHO, the answer to your question is no. The Arduino has certain hardware and software assumptions in it, that simply buying an ATMEGA328P is not going to resolve for you.

    The Arduino is a complete development platform. It is one of its greatest strengths and greatest weaknesses at the same time. You have control over a variety of hardware and software, but are limited to the configurations available. AFAIK, once you develop your software on an Arduino, it must run on an Arduino. If you want to program chips with your software without the additional overhead on an Arduino - then you need to bite the bullet and develop with the processor on its own, buiding your own supporting board and possibly writing your own sofware libraries to interface with such things as serial comms, servos, storage, displays etc... An advantage of the Arduino is that many of these software libraries are already available. If its just cost, there are Arduino closes available for less cost, but your milage may vary.
     
  10. flat5

    Active Member

    Nov 13, 2008
    403
    17
    http://www.banggood.com/buy/Arduino.html

    For example:

    UNO R3 ATmega328P Development Board For Arduino No Cable
    http://www.banggood.com/UNO-R3-ATmega328P-Development-Board-For-Arduino-No-Cable-p-964163.html

    Ethernet Shield Module W5100 Micro SD Card Slot For Arduino UNO & MEGA
    http://www.banggood.com/Ethernet-Sh...-Card-Slot-For-Arduino-UNO-MEGA-p-908461.html

    Micro SD TF Card Memory Shield Module SPI Micro SD Adapter For Arduino
    http://www.banggood.com/Micro-SD-TF...PI-Mciro-SD-Adapter-For-Arduino-p-919914.html

    I have bought these and am very happy I did. Also bought many other Arduino parts and other electronics parts from Banggood. Great company. Great prices and free shipping.
     
    Last edited: Jun 28, 2015
  11. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,387
    497
    No.
    ATMEGA328P by itself does nothing. It requires supporting circuit. For example:
    - it needs a crystal to provide the clock signal, which means you need crystal and two capacitors
    - it needs another chip to provide communication from pc (via USB) to ATMEGA328P, this chip needs its own circuit
    Additionally, ATMEGA328P from distributors comes completely empty. The ATMEGA328P in your Arduino board is not empty, it has bootloader software already placed into the chip. So, you either buy ATMEGA328P with bootloader, or you buy programmer and use this programmer to load your program into the empty ATMEGA328P that you got from distributor.

    If you already have Arduino board, you can use this board to program the empty ATMEGA328P chips.

    Generally speaking, you can:
    - use another Arduino board for your final product, even though it has more stuff than you need, the clones are quiet cheap.
    - build your own board with only the features you need/want (Arduino provides the schematic of their boards for free, so you can download it, look what they have and just not use/build stuff that you don't need).
    - as someone else pointed out, you can "downgrade" to smaller/less features board, since you now have the experience of writing program for one Arduino board, you should be able to port it to a different board.
     
  12. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    If you have access, you should read the "Beyond the Arduino" series in Nuts and Volts magazine. It describes how to do what you are asking about, i.e., using an Atmega chip separate from an Arduino board. However, it's still easier to use another microcontroller family, such as the PICAXE.
     
  13. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
    633
    13
    Thank you everyone for your help it certainly has been enlightening .

    If I use the Arduino to develop my project and test it then I can develop it in a PIC. I understand I will have to use the PIC libraries and configure it but I will have the basics of a working project already developed.

    I always live in hope that one day something I develop and build will sell so the transition to a PIC seems the most practical?
     
  14. sirch2

    Well-Known Member

    Jan 21, 2013
    1,008
    351

    This is not true, I have done exactly as the OP suggested, develop on Arduino and then use a bare atmega 328 on a board to run exatctly the same code. All Arduino provides as far as hardware goes is a voltage regualtor, a USB-serial interface and an LED (on some boards) connected to PIN 13. Additionally the Adrunio hardware is open source so you can copy the parts of the design you need to build your own.


    the atmega 328 has an 8MHz internal oscillator and there is an Arduino Board definition for making use of this.

    A USB-serial chip or bootloader is NOT needed if you have a programmer, you can just load your compiled Arduino binaries on to the bare atmega. An Arduino can BE USED AS A PROGRAMMER, - https://www.arduino.cc/en/Tutorial/ArduinoISP or you can buy somehting like a USBTinyISP.

    There is an awful lot of misinformation about Arduino out there...
     
    tracecom and RodneyB like this.
  15. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,387
    497
    That is part of my point. OP DOES NOT have programmer.

    Also that banggood website has chips with bootloader, which is good. You can use it to build your own board with just the features you need/want.
     
  16. sirch2

    Well-Known Member

    Jan 21, 2013
    1,008
    351

    The OP does (or will) have a programmer. As I said he can use his Arduino AS A PROGRAMMER. So, he buys an Arduino, develops his project and then productionizes it and uses the Arduino from the proto-type as a programmer.

    The bootloader occupies program space and causes lag on reset since it waits for input over serial, so no real advantage in having that in a production product.
     
    RodneyB likes this.
  17. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    2,802
    832
    I'd like to ask a question to understand this process... Using the Arduino as a programmer, you perform the following steps.
    1. Connect the Arduino to the PC
    2. Upload ArduinoISP
    3. Connect the Arduino to the AVR via a special SPI cable.
    4. Use avrdude to write the program to the Arduino (and hence the AVR
    My question, is how do you get the program on the PC in the first place? If you develop the program on the Arduino, how do you get it off to the PC, to be subsequently uploaded to the AVR? Wouldn't uploading ArduinoISP overwrite the program?

    I am sure I am missing something basic, so please enlighten me,
     
  18. sirch2

    Well-Known Member

    Jan 21, 2013
    1,008
    351
    It's simpler than you think, you don't have to get the program off the Arduino because the Arduino IDE runs on your PC and that is where you developed and compiled the program so the binary file is already on your PC.

    All the Arduino IDE is is an editor and compiler. It comes bundled and preconfigured with AVRDude which sends compiled binaries over serial to some device, that device can be an atmega running a bootloader or a programmer of some sort including an Arduino running ArduinoISP (what ArduinoISP does is essentially to read data from the serial input and send it out over the SPI interface) .

    The atmega chips are programmed via SPI while holding the reset pin. So you just need to connect the SPI lines on the target chip, control it's reset pin and obviously provide power. There is a fairly standard 6 way cable for doing this but it is perfectly possible to just jumper it in on a breadboard for example.
     
    djsfantasi likes this.
  19. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    2,802
    832
    Another d'oh moment. I knew that about the IDE - just conveniently slipped my mind.
     
    sirch2 likes this.
Loading...