# freifunk-open-mppt

**Repository Path**: shareceo/freifunk-open-mppt

## Basic Information

- **Project Name**: freifunk-open-mppt
- **Description**: Open hard- and software solar maximum power point tracker
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 1
- **Forks**: 0
- **Created**: 2019-09-23
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

These are preliminary sources and CAD files from the
Freifunk-Open-MPP-Tracker project.


## SOME LICENSE-FOO:
This is a Open-Source and Open-Hardware project under General Public License
v2 and Creative Commons - Attribution - ShareAlike 3.0.
For more information, check out the LICENSE file.

## A QUICK OVERVIEW OF THE DIRECTORIES:

#### AVR-FUSES
Contains a XML configuration file to program the fuses of the AVR. I am
using the AVR dragon board and AVR-Burn-O-Mat software to program the fuses.

#### SCHEMATIC AND BOARD
Electronic CAD files and component libraries, made with KiCAD. KiCAD is a free and
open ECAD tool.  Due to the intend to provide a open hardware and open
software project for DIY home-brewers, I have decided to use a free and open
source ECAD software tool, too. It is my first project with KiCAD, though.

#### uC-SOURCECODE
AVR-GCC source and Makefile. 

## SOME NOTES ABOUT THIS DESIGN
Basically this hardware has two building blocks: 
The MPP controller section and the buck converter.

At the moment, the buck converter section is based on the el cheapo and
low-fi MC33063 controller chip.  It can easily be replaced by a faster and
more fancy switch converter IC to construct a more powerful and slightly more 
efficient buck converter section.  However, with the external powerful P-MOS
switches, the efficiency was already around 94% with the first prototype 
(measured at 2 Ampere output current).

One reason to replace the MC33063 might be noise. Under low load, the
MC33063 will skip pulses of the PWM, so the switching frequency becomes
audible. 

# External references

* https://wiki.freifunk.net/Freifunk-MPP-Tracker
* https://wiki.freifunk.net/Freifunk-Mast