Hi. I buyed an Arduino Uno for Christmas, so I'm very new here. I want to program cheap microcontrollers, and I found the ATTiny13a.
I read how to program it in this guide: Link to guide
In the connection scheme, you can see that 4 pins are being used by the Arduino: (1, 5, 6, 7)
But... Are they still usable? I have to do something in special to program them? I want to know before I buy the ATTiny, because things in Argentina aren't that cheap
Thanks in advance.
P.D.: Sorry for my bad English. I'm from Argentina.
I have got the ATTiny13a to do some really awesome things, they have very small memory and only 64 bytes of ram but its actually a lot of fun trying to squeeze them to get the most out of them
Thanks for the info. So, you mean I can use all of them? (Well, except Power and Ground)
Another question: I wanted to put a project into my (future) ATTiny, but it has just 1k of flash, and my projects are too big (about 10k). How can I do them 'smaller'?
If you are programming an Atmel chip this way, you have to take it to a specific programming mode.
That's done by brining pin 1 (/reset) to a specific level in this case bring and keep it LOW during programming.
Pins 5, 6 and 7 are used as databus for programming, MOSI (RxD), MISO (TxD) and SCK (serial clock) respectively.
This means you will use these pins for this function during programming, but they are free for whatever you want them to do (and they are capable of).
You need to study the datasheet (click !) to find out what pins can do and how to use them.
MlucianoEze:
Thanks for the info. So, you mean I can use all of them? (Well, except Power and Ground)
yes, but you cant use the reset pin unless you disable it, but if I were you I would just stick with the 5 pins you CAN use for now
Another question: I wanted to put a project into my (future) ATTiny, but it has just 1k of flash, and my projects are too big (about 10k). How can I do them 'smaller'?
You could possibly trranslate all of them into assembly language which would make them more efficient, OR perhaps buy a few ATTiny85 chips - they have 8k of flash rom space and 512 bytes of ram and a little bit more expensive than an ATTiny13 but are the same size
mcnobby:
yes, but you cant use the reset pin unless you disable it, but if I were you I would just stick with the 5 pins you CAN use for now
To expand on this, once you co-opt pin 1 for use as GPIO, you can't reprogram the chip without a high voltage programmer (which the typical arduino-as-isp/usbasp/etc. are not)..
