Preamble
You don’t have to buy an Arduino board, in order to use the Atmel ATmega series of MCU. You could always build your own.
Minimalistic
There is the minimalist Arduino kit, without the external crystal, that fits on a Mini 170 breadboard.
I am unable to find any images, or links to kits, although in 2015 there were many examples available on eBay. Here are a couple of implementations
Standalone
The is the standalone Uno clone, with FTDI interface. Note the incorrect wiring in the photos, see Arduino Standalone – photo shows incorrect pin wired to MOSI
The dark green wire should go to pin 17 and not pin 16.
ATmega1284p
Also found this ATmega1284p kit:
Description
Here we have an ATmega1284p kit. If you have ever needed more pins on your Arduino, more ram because your sketches have run out of memory, more UARTS, more EEPROM while logging data, then this kit is for you.
You could opt for the Arduino Mega 2560 but it costs a lot especially if you are going to embed your Arduino Mega into your project. So that’s where the ATmega1284p comes in. All the extra Pins and memory, at a fraction of the price.
Our ATmega128p kits come fully bootloaded with the Mighty Optiboot bootloader and we provide a full build tutorial in our “how to” section. We will take you through building the kit, as well as uploading sketches.
The bare bones kit includes all the components needed to have a working Arduino ATmega1284 but does lack USB interface and power regulation, you would need a regulated 5V power supply to run this circuit. We offer kits with either the FTDI or CP2102 USB/TTL converter and these units allow for USB communication and USB power to the ATmega1284.
We also provide a range of options for this kit, from bare bones to full kit with breadboard and USB / TTL converter.
ATmega comparison table.
Feature: 328P 1284P 2560P RAM 2k 16k 8k Flash 32k 128k 256k EEPROM 1k 4k 4k UART 1 2 4 IO Pins 23 32 86 Interrupts 2 3 8 Analog Inputs 6 8 16
How To
ATmega1284p Kit
Add the Atmega1284Add the atmega chip to the breadboard.
Top Power linesConnect the two power and ground rails.
Power to the Atmega !Connect pin 10 and 30 to the Power rail. Connect pin 11 and 31 to the ground rail. Also connect the o.1uF capacitor accross power and ground.
Add the Clock & CapsAdd a 16 MHz external clock between pin 12 and 13, and add two 22 pF capacitors running to ground from each of those pins.
Add reset pull-up resistorAdd a 10k ohm resistor between power and reset on pin 9.
LEDAdd a 330 ohm resistor from pin 2 to the anode of the LED and the LED cathode to ground.
Blank CanvasThere you have it, all you need to get going with your atmega1284. Just connect power and upload a sketch (more on that later)
Normally you would have to burn a bootloader to your atmega, but all our kits come pre-loaded with the Optiboot bootloader.
Preparing to uploadNow we need a USB interface. We will set up the circuit to easily accept a USB to TTL module so that the atmega1284 can be connected to a computer and receive sketches.
We will need pin 9, 14, and 15 (Reset, RX, and TX). Here we connect these pins to open rows further down the breadboard for easier and neater connection. Notice the 0.1uf capacitor on the reset line, this allows for auto reset when programming with USB to TTL boards that do not provide auto reset functionality.
Add a USB to TTL converterHere we connect RX and TX to the converter’s TX and RX. Also notice that as this unit does not have a reset line, we connect reset to DTR. Then just hook up GND and 5V and you are ready for business.
Upload a SketchPlug your USB to TTL converter into a computer and your circuit will be powered and ready for a sketch. Please note that you would need to select the “Mighty 1284p 16mhz using Optiboot” under the board menu item. This board option is available in Arduino 1.0.5 and below.
If the Mighty 1284p board is not available in you version of the arduino software you can follow the following steps, but the latest versions of the arduino software may not support these steps.
- Download this ZIP File
- Unzip it a folder called ‘hardware’ off your sketches directory, e.g. /Users/Username/Documents/Arduino/hardware/mighty-1284p
- Restart the IDE
- Select Tools > Boards > Mighty 1284P
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