A key design feature of the om644p is that the ATmega644p is packaged on a compact carrier board that is socketable using a 40-pin DIL style package with pins spaced 0.1” apart. This pin spacing allows the device to be on breadboards and in other thru-hole applications. Here is a feature summary of the om644p device:
- ATmega644p with 14.7456 MHz crystal. A 16 MHz crystal is optional.
- 32 I/O pins in a 0.1” DIL format (provides access to ports A, B, C, and D of the ATmega644p).
- Compact size (2” x 0.7”) for the supplied functionality.
- A RS232 transceiver that provides true RS232 voltage levels on USART0.
- A miniature slide switch that allows the user to choose the voltage levels for serial channel 1 between RS232 levels (± 15V) on pins 1 and 2 versus logic levels (0V-5V) on pins 19 and 20.
- 5V regulator rated up to 100mA and green power indicator LED.
- Green and red active low monitoring LEDs connected to I/O pins 5 and 7 on port D.
- Ability to add PDIP-8 SPI EEPROM, FRAM or Flash memory.
The software install package for the Oak Micros devices also includes two example programs. The first is a hello world style application that flashes the built-in LEDs and the second shows how to use the extended RAM capabilities provided by the 64K RAM daughterboard of the om128. The source code is fully commented and is easy to follow, even for a novice. The software package also includes the binary and source code for the bootstrap loader. Significant updates to the latest software package include:
- Support of both om128 and om644p devices.
- Ability to query the device type, boot loader version and lock bits.
- Automatic detection of the download baud rate (thanks Spamian).
- Boot loader self-updating facility.