Arduino Forum

Using Arduino => Microcontrollers => Topic started by: Protoneer on Aug 04, 2013, 07:21 am

Title: Bare-bone Leonardo Schematics
Post by: Protoneer on Aug 04, 2013, 07:21 am
Hi there,

I have developed a general perpose shield that adds an extra ATMega328(info.protoneer.com/2 (http://info.protoneer.com/2)) to your setup. Currently I program the secondary
MCU with the ArduinoISP sketch. This works fine but I would like to add a USB port to it so you can program and send serial commands independently to the secondary MCU shield.

The ATMega32U4 would work well for this and because the Leonardo is based on it,it would add full compatibility for my shield.

What would be the bare minimum components needed to make a board that is Leonardo compatible?



Title: Re: Bare-bone Leonardo Schematics
Post by: Osgeld on Aug 04, 2013, 07:55 am
here is the schematic

http://arduino.cc/en/uploads/Main/arduino-leonardo-schematic_3b.pdf

I am planning doing this myself, you can remove the extra led's and the power stuff if you plan on only using USB power, maybe L1 which is a ferrite bead to help clean up the analog input voltage, but there is not really that much to it
Title: Re: Bare-bone Leonardo Schematics
Post by: Protoneer on Aug 04, 2013, 08:00 am

here is the schematic

http://arduino.cc/en/uploads/Main/arduino-leonardo-schematic_3b.pdf

I am planning doing this myself, you can remove the extra led's and the power stuff if you plan on only using USB power, maybe L1 which is a ferrite bead to help clean up the analog input voltage, but there is not really that much to it


Yes... there are a bunch that can be removed. Would you be interested in teaming up with me to get this solved?

I have also looked at : http://imall.iteadstudio.com/itaeduino-leonardo.html - Have a look under downloads for the schematics

Its always good to have a few versions of a design to compare... ;)
Title: Re: Bare-bone Leonardo Schematics
Post by: Protoneer on Aug 04, 2013, 08:03 am
I have also looked at the Teensy Ver2 schematics and Freetronics Leostick...

http://pjrc.com/teensy/schematic.html
https://github.com/freetronics/LeoStick/blob/master/LeoStick.pdf

The bit that confuses me is that even if they use the same MCU they have their own hardware configurations and don't use the Leonardo setup.
Could that just be a Bootloader thing?
Title: Re: Bare-bone Leonardo Schematics
Post by: Osgeld on Aug 04, 2013, 08:57 am
probally, and the teensey has been around longer