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
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
cjdelphi:
you only have 2pwm and 3analog in's or made to be dig out / inbut... 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?
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)
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
CrossRoads:
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 sketchesplace 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
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.
'
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
kylem:
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.
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
Use pins like these for the FTDI and ICSP header.
http://www.dipmicro.com/store/HDR40X2M
and if you need some female headers
http://www.dipmicro.com/store/HDR08X1FL
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..
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.
fungus:
Those are huge...try this: http://www.geocities.jp/arduino_diecimila/obaka/project-2/index_en.html
A novel approach, next step from that must be surface mount though most of the parts are already mounted on the surface of the MPU LOL
There are already some very SMALL.. all SMD Arduino boards..
femtoduino: Tiny Femtoduino, The Smallest Arduino Compatible Board | Arduino Blog
digispark: http://www.kickstarter.com/projects/digistump/digispark-the-tiny-arduino-enabled-usb-dev-board
Tiny Duino: http://www.kickstarter.com/projects/kenburns/tinyduino-the-tiny-arduino-compatible-platform-w-s
take your pick.. Im still not clear if you want smaller 'features'? or a smaller board/footprint..??
xl97:
There are already some very SMALL.. all SMD Arduino boards..
The standard Arduino Pro Mini is pretty small, too...let's not forget it.
I think the OP went home though.
Was bored so I tried to make a tiny attiny2313 (DIP) board with ISP headers. Here is what I got: