Beat707 XXL LE Official Release
check out the video showcasing the product below.
This initial version is BIG, hence the XXL name. 
LE is for Limited Edition, since it does not feature the LCD and SD Card that the next version does. Still, the feature list is great!
Beat707 XXL LE has only MIDI output, no LCD and no SD Card. Uses the ATmega328 EEPROM to store data. This unit can handle 8 drum tracks, 2 accent tracks and 6 patterns. Each pattern is actually a combi of 4 x 16 steps plus extra double steps. So in total we have 128 steps per pattern. We have setup a very easy way to edit all those steps. We have steps A, B, C, D for each set of 16 steps. Also, you can set a set to "double-step" and it will blink instead of light-up. All options are set into the program itself which can be altered and uploaded using the Arduino IDE.
- Uses only Two ATmega328 Chips and basic components.
- Work with a 500mA 5V power supply.
- Can use 4 pin mic left and right connectors, instead of 6 pin mic connectors.
- Settings such as track drum notes and midi channels are set in code, while BPM and Steps# can be changed in the interface itself and is saved along the other data into the internal EEPROM.
- Multiple units can be side-chained.
We are selling it as a DIY Kit, with options with and without the components. The kit is easy to build since we did not use anything hard to solder. Check the other videos for more details about the Beat707 XXL PCB.
PCB Details Video:
Beat707 XXL LE Open-Source Software
https://github.com/Beat707/Beat707-XXL-LE
Beat707 XXL Manual
http://www.beat707.com/downloads/Beat707_XXL/Beat707%20XXL%20Manual.pdf
Beat707 XXL PCB PDF
http://www.beat707.com/downloads/Beat707_XXL/Beat707%20XXL%20PCB.pdf
or PNG
http://www.beat707.com/downloads/Beat707_XXL/Beat707%20XXL%20PCB.png