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Topic: Shrinkify Arduino Project (Read 8452 times) previous topic - next topic

kylem

I have an arduino Project and i am using all the I/O Pins. i would like to make it a much smaller and cheaper unit for a project. What would i be able to use to kinda replace what the Arduino Does. Please Help

cjdelphi

you only have 2pwm and 3analog in's or made to be dig out / in

but... you're limited to size of program less mem, flash etc.. oh and there's not uart support on the attiny85..

for more pins you need shift registers.. if you did attempt it

kylem


you only have 2pwm and 3analog in's or made to be dig out / in

but... you're limited to size of program less mem, flash etc.. oh and there's not uart support on the attiny85..

for more pins you need shift registers.. if you did attempt it


Would i not be able to use the ATmega328 with the bootloader loaded?

CrossRoads

#3
Nov 05, 2012, 03:22 pm Last Edit: Nov 05, 2012, 03:25 pm by CrossRoads Reason: 1
What part of the Arduino functionality would you like to keep?
At a minimum you need:
the '328P
16 MHz crystral
two 22pF caps
100nF caps on VCC, AVCC pins
using analog? need 100nF cap on the Aref pin
10K reset pullup resistor
diode such as 1N4158 across the resistor (anode to reset pin, cathode to Vcc)

optional:
Header pins to connect FTDI Basic/FTDI cable, and 100nF cap to connect to Reset pin
or
header pins to connect to ICSP header for rebootloading or for installing bootloaderless sketches

place to connect 5V wallwart, or a battery, or a 5V regulator

Here's an example for a ATmega1284P type board, a '328P would use a smaller connector
This one has both FTDI and ICSP headers, but does not have the diode.
It has screw terminal for bring in 5V power from a wallwart or 4.5V from a triple-AA battery pack (I've used both)
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

cjdelphi

yeah... but you'd need a crystal and the other components i can't imagine being smaller than an arduino board by the time you're done

kylem


What part of the Arduino functionality would you like to keep?
At a minimum you need:
the '328P
16 MHz crystral
two 22pF caps
100nF caps on VCC, AVCC pins
using analog? need 100nF cap on the Aref pin
10K reset pullup resistor
diode such as 1N4158 across the resistor (anode to reset pin, cathode to Vcc)

optional:
Header pins to connect FTDI Basic/FTDI cable, and 100nF cap to connect to Reset pin
or
header pins to connect to ICSP header for rebootloading or for installing bootloaderless sketches

place to connect 5V wallwart, or a battery, or a 5V regulator

Here's an example for a ATmega1284P type board, a '328P would use a smaller connector
This one has both FTDI and ICSP headers, but does not have the diode.
It has screw terminal for bring in 5V power from a wallwart or 4.5V from a triple-AA battery pack (I've used both)




Your idea seems like what i am looking for. basically what i am wanting to do is make a unit that uses the atmega328 chip as the brain so i need all the outputs but dont need all the other things like the serial com or all of the analogue inputs. all i need is the I/O pins. could you please help with a schematic of your board or if you could help with exactly what i need?
Thanks

Riva

You could drop the crystal and it's 2 capacitors and replace with a resonator or by burning another bootloader and setting the relevant fuses you could run off internal 8Mhz oscillator and not need crystal/resonator at all.
For an off the shelf solution you could try a mini http://arduino.cc/en/Main/ArduinoBoardMini pro mini http://arduino.cc/en/Main/ArduinoBoardProMini or nano http://arduino.cc/en/Main/ArduinoBoardNano

CrossRoads

Ok, here it is, somewhat crudely drawn, have better tools at home.
Not much is really needed.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

kylem


Ok, here it is, somewhat crudely drawn, have better tools at home.
Not much is really needed.
'
Thank you very much for your help, i will let you know how i do but i have one question. what do i connect the icsp pins to.
thanks

fungus


Would i not be able to use the ATmega328 with the bootloader loaded?


Yes. You can use a Mega328 (28 pins), a Tiny2313 (20 pins), a Tiny84 (14 pins), a Tiny85 (8 pins)... whatever suits your requirements. All of them will work with no external components (although it's a good idea to put in at least a decoupling capacitor).

Bootloaders are optional. In fact I don't recommend them for bare chips, get a $12 ISP programmer instead so you can configure the chip's "fuse" options as well as upload code.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

bperrybap

If you are only doing a one off project, have you considered just buying a teensy board?
http://www.pjrc.com/teensy/
It is about as small as you can get and often for one offs, even the cost at $16
is very competitive to a DIY prototype using a perf/stripboard unless
you happen to have components laying around.

--- bill

CrossRoads

Use pins like these for the FTDI and ICSP header.
http://www.dipmicro.com/store/HEADS40G
http://www.dipmicro.com/store/HDR40X2M

and if you need some female headers
http://www.dipmicro.com/store/HDR08X1FL
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

xl97

Is it the functionality you want 'gone'.. or just simply a smaller footprint of the 'Arduino board/brain'?


Maybe using a different/smaller Arduino circuit will help?

something like this perhaps:








green one is a commercial kit (about $10 bucks or so).. lacks any voltage regulation..

the other one is my home made, DIY home brew/etched version..


fungus

Those are huge...try this: http://www.geocities.jp/arduino_diecimila/obaka/project-2/index_en.html






No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

CrossRoads

Back in #8, you asked about ICSP: those connect to +5, Gnd, Reset, and SCK, MISO,  MOSI.
Can be a header as I did, or just connect temporarily to the needed pins.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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