The MHVBoard is a low cost Arduino clone, based off the Metaboard.
It offers a TTL serial port, USB programming, ICSP, breadboard compatible headers and hardware already set up for software USB via V-USB.
While the original Metaboard did not choose to issue a license, our revisions are licensed under TAPR Noncommercial Hardware License.
Getting one You can pre-order an MHVBoard R7 from the MHVBoard Pozible project page.
Features Supports native USB direct to the microcontroller via V-USB TTL level serial port Programming via USB Onboard prototyping area for additional hardware Shield compatible - Revision 4+ only Plugs into double-width breadboards (Revision 1-3), and single width breadboards (Revision 4+) Atmega328P microcontroller with 30kB flash, 2kB RAM, 1023Bytes EEPROM available ICSP header to update the bootloader All through-hole construction (except for a voltage regulator with large easy to solder legs) for easy hand assembly Supports Arduino and Flame runtimes, as well as raw AVR-GCC 20MHz clock - your code runs faster than the Arduino boards Pins labelled both with Arduino pin numbers and port/pin numbers Automatic detection of power source - USB or external power 4 mounting holes for extra stability AREF decoupled for improved ADC accuracy Onboard LED can be disabled to reduce loading on the line Up to 1A can be drawn from the 3.3V line, and 1.5A from the 5V line (when using an external power supply) Differences to the Arduino series Native USB interface for uploading (USBasp), no serial ports involved Serial port brought out on a TTL Header Arduino pins 2 and 4 are used for USB communication. If you connect additional hardware to these pins, your program should not use the USB port. This hardware should also be disconnected before connecting to your computer Arduino pins 0 and 1 are normally used for the Serial port, if your program does not use the Serial port (since USB is available), these pins are available for use Breadboard compatible pin headers (no shields) - Revision 1-3 Arduino shield and breadboard compatible headers - Revision 4+ 20MHz clock vs 16MHz on the Arduino Due to the additional filtering on AREF, it takes time for AREF to stabilize after a different reference voltage has been selected. The first reading after the reference has changed should be discarded. 3.3V current up to 1A (vs 50mA), and 5V current up to 1.5A (with a suitable heatsink on the 7805 regulator) Instructions R7 Assembly R2 Assembly Getting Started in the Arduino Environment Troubleshooting Useful Information Credits Big thanks go out to the many open-source and commercial projects that made this project happen.
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