Help !

Projects General Guidance
1

I have posted a few problems i am having on another section, but i thought i would try this one, the Fritz i have uploaded works and works well enough for my project, which is to build a Temperature Controlled CNC cabinet 12 volt dc Fan.

As i have already said, the Fritz works on my Breadboard, what i would like to do know is to replace the Arduino Uno 3 with say a ATtiny84pu, this saves the Arduino for other projects, but i am suffering in that i cannot find enough info to do it, i have found a Fritz to use the Arduino as an ISP to program the Tiny84, but what i need is help with a Fritz to connect the lcd and LM 35 to the Tiny 84 when the 84 replaces the Arduino, can anyone help?

Final Fan Sketch_bb.jpg
Final Fan Sketch_bb.jpg2652×2238 486 KB

2

Basically, you need an ATTiny84 datasheet (http://www.atmel.ca/Images/doc8006.pdf

Choose pins for the various components, replace the Uno in the Fritz with a 14-pin IC, and re-run the wires to your chosen pins. As for the code to use the different pins, I really don't know.

3

Thanks

I had thought of an ATtiny84 after studying ATtiny85 + a shist register, but i could not find any info, so are you saying a ATtiny84 would work, if yes can you steer me in the right direction to get a Sketch?

4

Hi, have you considered one of these.

I have a couple, but haven't played with them yet, they are the arduino uno chip, all ready programmed with the bootloader,and xtal that you need to run it'
You program it in your arduino (If you have the dil chip version) then plug it into your own PCB.
Or try the arduino nano, this has the programming advantages of the uno, with the advantage of small size.

Just a suggestion, also can you re edit the subject of this thread to be a bit more descriptive of your needs.
"Help needed; convert an arduino uno to atiny84 with LCD LM35"
There is stack of space in the subject line, this way you will get more hits from forum member who can help you.

Nice little project by the way.

Tom...... :slight_smile:

5

manofgresley:
I had thought of an ATtiny84 after studying ATtiny85 + a shist register, but i could not find any info, so are you saying a ATtiny84 would work, if yes can you steer me in the right direction to get a Sketch?

Well, if I were doing the project, I'd probably do it on an Arduino Pro Micro. It's basically a Leonardo on a small board. You can see one at https://www.sparkfun.com/products/11098 It's a nice little board.. about 1.3 x 0.7 inches ( 33 x 18 mm). Your code should run on one, and you can program it with the IDE just like an Uno (except you specify a Leonardo board).

They are about 20 bucks. I picked up several similar ones from China for about 5 bucks each, but they do tend to take a lot longer to arrive. One of them is nearly a garage-door opener with a keypad and door open/closed sensing, another will be a cloud sensor, and yet another, a driveway monitor (not started yet), all of which will be on an RF29L01 radio network . They are just great for projects that don't need a lot of pins.

6

Hi All

Many thanks for your advice and recommendations, now i know what to get, and knowing it will work, can you point me to a Fritz or other type of schematic circuit to include the chip??

7

manofgresley:
Many thanks for your advice and recommendations, now i know what to get, and knowing it will work, can you point me to a Fritz or other type of schematic circuit to include the chip??

So are you going with the chip on a custom board? Not with something like a Nano or Pro Micro?

If so, I can't do more than offer some advice on how to go about it, as it's going to be more effort to do it than I want to do for something that isn't my project.

Arduino pins are not the same numbers as the pins on the chip itself. If you look at the Uno schematic and pinout, you'll see how the pins map between the chip and the headers on the board. What you need to do is to find pins that will work for both the Uno and the chip you want to use. The ones that will work for noth are those that are connected to the same registers and register bit numbers. For instance, D3 is available on both the ATTiny86 and is brought out on the Arduino Uno on pin 3, so when you compile, that pin can still be used in the same manner. However, the tough part comes when you have to figure out how the pin on the ATTiny is apecified, because it is multi-purpose, and there may be another register you have to set to tell the chip what function that pin should have. On the other hand, it may just compile without change.

One of the nice things about the Arduino system is that it gets rid of all the engineering required to design the circuit, lay out the board, and learn all about the finer points of whatever chip you are programming, opening it all up to folks who would otherwise find it too daunting. For the ATTiny, you will also have to supply the circuit for programming it, the reset circuit, the bypass caps, and so on.

Again, I HIGHLY recommend the easy route, a Nano, Micro, or Pro Micro, which will play well with the Arduino IDE, and which will allow you to not only hook the circuit up easily, but will also allow you to use the same sketch with little or no change. in addition, size of a Pro Micro is not a lot larger than just the ATTiny84 chip itself, and it seems like a win-win to me.