Ardunio Newbie

Using Arduino Microcontrollers
1

Not sure if this is the right section but here goes.

My interest is model railway control using DCC and to date the projects that I have built have used Microchip PIC series of micro-controllers. Recently while searching the web I came across a site (https://rudysmodelrailway.wordpress.com/) using a ArduinoTiny 85 board. I would like to try to utilise such a system but I have no experience with Arduino or ATTiny micro-controllers so I would like to pose a number of questions if I may.

There are several Arduino Tiny85 boards advertised on the web. Are they likely to be interchangeable? Does it matter which one I buy?

How do I program the board? For the Microchip projects I have several programmers (PicKit 2 etc). Would I use the USB port on the Tiny85?

Which software must I use? The project site talks about Arduino IDE. Does the IDE software compile the program into a way that the board / chip can understand ie equvilent to a PIC hex file?

There also seems to a number of Arduino UNO boards available at differant prices and model numbering. Again will the external connections be the same irrespective of what is mounted on the board.

2

mcnaugg:
There are several Arduino Tiny85 boards advertised on the web. Are they likely to be interchangeable? Does it matter which one I buy?

Do you have links? Do they have SPI bus connections?

How do I program the board? For the Microchip projects I have several programmers (PicKit 2 etc). Would I use the USB port on the Tiny85?

You can buy "USBASP" programmers very cheaply on eBay. They plug into a USB port, then connect to the ATtiny85's SPI pins: MOSI, MISO, SCK and RESET. (A 10K pullup resistor is needed on the 'RESET' pin.)
I made a small board for programming ATtiny85 chips, but it could probably be done on the Tiny85 boards that you mentioned. Otherwise, it can be done on a breadboard.
Here's my "USBASP" programmer, (a couple of $ on eBay), and my little ATtiny85 programming board. (Alongside a board for ATMega328P programming):-
ATtiny85 328P Prog Boards.JPG

Which software must I use? The project site talks about Arduino IDE.

The Arduino IDE can be used in conjunction with a USBASP programmer to program ATtiny chips.
The "USBASP" programmer can be selected under >Tools >Programmer, then you click on "Upload using programmer" to burn the firmware to the chip.
Edit: I forgot to add, before uploading the program, you must click on "Burn bootloader" to set the chip's fuses for the chosen oscillator, BOD etc. It doesn't actually write a bootloader,(which isn't needed) - it just sets the appropriate fuses on the chip.

Does the IDE software compile the program into a way that the board / chip can understand ie equvilent to a PIC hex file?

The "Upload using programmer" mentioned above takes care of this. And yes, it's a *.hex file.

To work with ATtiny chips from the Arduino IDE, the "Tiny" cores must first be installed.
The best that I've found are available here, courtesy of fellow-member DrAzzy:-
ATtiny Core
He also has full instructions on his page.

If you have further questions during installation, you can always post them here.

3

mcnaugg:
Not sure if this is the right section but here goes.

It's as good as any - don't fuss.

mcnaugg:
My interest is model railway control using DCC and to date the projects that I have built have used Microchip PIC series of micro-controllers. Recently while searching the web I came across a site (https://rudysmodelrailway.wordpress.com/) using a Arduino Tiny 85 board. I would like to try to utilise such a system but I have no experience with Arduino or ATTiny micro-controllers

It grows on you. If you program in "C", you only have to get used to the behaviour of the on-board peripherals.

mcnaugg:
so I would like to pose a number of questions if I may.

Ask away. :grinning:

mcnaugg:
There are several Arduino Tiny85 boards advertised on the web. Are they likely to be interchangeable? Does it matter which one I buy?

Moderately interchangeable. Either they interface by USB having had a "V-USB" emulation loaded through ICSP (before you get them) or you do the ICSP programming with another Arduino or cheap ISPASP module.

mcnaugg:
How do I program the board? For the Microchip projects I have several programmers (PicKit 2 etc). Would I use the USB port on the Tiny85?

One option, or a (very inexpensive) USBASP module.

mcnaugg:
Which software must I use? The project site talks about Arduino IDE. Does the IDE software compile the program into a way that the board / chip can understand i.e. equivalent to a PIC hex file?

Yes, and performs the download to the chip.

mcnaugg:
There also seems to a number of Arduino UNO boards available at different prices and model numbering. Again will the external connections be the same irrespective of what is mounted on the board.

No, but that will not be a particular problem.

Perhaps more to the point, it may be more sensible to use an Arduino Pro Mini
, only slightly larger, probably cheaper, and with substantially more capability.

4

I agree with Paul__B, use an Atmega328P board: they are inexpensive, fully supported in the ArduinoIDE, and directly applicable to mainstream Arduino. I do attiny85 but it really is not a beginner area, rather it is far enough off-the-main-path to cause a newbie frustration - and the forum expertise is not as broad as atmega328.

Both Adafruit and Sparkfun provide "mini" boards under $10. You can get them on eBay for under $2,
$2 Arduino Mini available in both 3.3V and 5V versions (16MHz vs 8MHz.)

Ray
My Projects

5