Network connected large 4-digit LED display

License

!! READ THIS FIRST !!
---------------------
! Edit the main.c file and change the lines:
! static uint8_t mymac[6] = {0x54,0x55,0x58,0x10,0x00,0x29};
! static uint8_t myip[4] = {10,0,0,29};

Check the file "Makefile" and change the LOADCMD line if needed.

More information about Makefiles can be found at:
http://tuxgraphics.org/electronics/200912/makefiles.shtml

For the first device you build you will not need to change the mymac line.
But you will probably need to change the IP address (myip). myip must be a
free address from the address range in your home network.

Example: you wlan router might have 192.168.1.1, your PC might have
192.168.1.2. This means you could e.g use 192.168.1.10 and leave some
room for more PCs. If you use DHCP then make sure that the address it not
double allocated (exclude it from the DHCP range).

You need an avr-gcc development environment in order to compile this.
See http://tuxgraphics.org/electronics/200901/avr-gcc-linux.shtml

To compile the software use the command:
make

Note: windows users may use and modify the supplied winmake.bat script.

The command
make load

Note: windows users may use and modify the supplied winload.bat script.

will execute the avrdude command to load the main.hex software (remote relay
switch on/off software, compiled from main.c).
E.g something like: 
   avrdude -p m88 -c stk500v2 -e -U flash:w:main.hex


Note your programmer might interfere with the enc28j60! For the avrusb500
with 30cm cable you can normally leave the cable on. For all other programmers
it is however saver to remove the programmer cable and power down/up the device.
This is because the SPI interface is used for loading of the software and 
communication to the enc28j60.

To see a list of all possible build targets run the command:
make help


Selecting the right clock source
--------------------------------

Tuxgraphics hardware sold as of march 2007 is prepared to use the clock
signal from the enc28j60. To use this you need to change the 
low fuse byte once from 0x62 to 0x60:


avrdude -p m328p -c stk500v2 -u -v -U lfuse:w:0x60:m


The above command can as well be executed by using the make
file. In a Linux shell you can just type:
make fuse

Note: windows users may use and modify the supplied winsetfuse.bat script.


Just change the lfuse from factory default to 0x60. 

Fuses of the atmega328p after programming:

The fuse settings of the atmega328p after programming
should be as below (the efuse has some unused bits and is dependent 
on the chip revision):
 lfuse reads as 0x60
 hfuse reads as 0xD9
 efuse reads as 0x07

details of the lfuse bits:
  CKDIV8 = 0
  CKOUT  = 1
  SUT1   = 1
  SUT0   = 0
  CKSEL3 = 0
  CKSEL2 = 0
  CKSEL1 = 0
  CKSEL0 = 0


If you are unsure what the current fuse setting are on the atmega
then you can read the fuse settings with a command like:
          avrdude -p m328p -c stk500v2 -v -q

The below list of fuses shows for reference purpose the settings
of a new and never programmed chip. 

The result should be this (default factory settings for atmega328p):
          lfuse reads as 62
          hfuse reads as D9
          efuse reads as 7


Compiling on non-Unix systems
-----------------------------

Please use the provided Makefile !!!

It will also work under Windows.

Take a look at the supplied winmake.bat and winload.bat file. The bat script
might be needed to set the environment correctly in order to use
the Makefile under windows.

Edit the Makefile to make the needed adjustments at the top
of the file.

More information about Makefiles can be found at:
http://tuxgraphics.org/electronics/200912/makefiles.shtml


Hardware 
--------

The whole system is based on the tuxgraphics ethernet board.
You will need the kit for the 4 digit large LED display and
a atmega328p based ethernet board.

The display has 2 push buttons in the upper right corner.
Only one of the buttons has a function in this software.
You can press the top right button during power on and it
you will git to a web page where you can change the IP
address of the board without re-compiling the software.


Updating the numbers on the display
-----------------------------------


1) From a desktop web browser such as firefox, MSIE, safari.... 
Just point the browser to the IP address of the board
and write the number that you want to display into the form
on the web page.
large LED display with web interface

2) You can use a command-line web browser such as lynx:
# lynx -dump "http://10.0.0.29/set?n=12:34"
This would cause the display to show "12:34"

Note that a space must be encoded in the URL as
it is not a valid URL character. It can be encoded
as "+" or "%20". The following example sends
the string "1  2":
# curl "http://10.0.0.29/set?n=1++2"
or
# curl "http://10.0.0.29/set?n=1%20%202"

3)
You can use the udpcom command (see directory udpcom):

# udpcom n=12:34 10.0.0.29
II: data: n=12:34, ip: 10.0.0.29 port: 1200
OK: 10.0.0.29: n=12:34

This would cause the display to show "12:34". The udpcom command is available for Linux, windows and Mac.



Revision history
----------------

2014-04-26: version 1.0 -- first version. 
2014-05-16: version 1.1 -- added udpcom binary for mac os
2014-07-27: version 1.2 -- udpcom updated
2015-02-15: version 1.3 -- add a push button counter example (main-counter.c)