Some theory first

A 5×7 dot matrix led is what the name calls: a dot led in a 5×7 matrix

The pinout is the following:

Source: Kingbright

In order to light the led you need to provide an active high(+Volts) to his ROW (RX) and an active low(Zero or ground) to his column (CX).

The tricky part is when you want to have a complete character and not a pix on.

Pseudo code:

ROWS=the_leds_you_want_on
C1 = 0
wait some time
C1= 1
ROWS=the_leds_you_want_on
C2 = 0
wait some time
C2 = 1

Repeat for the 5 columns.

Doing that with the correct frequency you will see a character.

Parts

1xAtmega168
7x1KΩ resistors for the ROWS
1x16MHz crystal
2x22pF capacitors
1x5x7 Common Cathode LED matrix
Your bench power supply at 5V

Connections to the display
COL1 PC0
COL2 PC1
COL3 PC2
COL4 PC3
COL5 PC4

ROW1 PD0
ROW2 PD1
ROW3 PD2
ROW4 PD3
ROW5 PD4
ROW6 PD5
ROW7 PD6

Source code: avrmatrix.tar.gz

References: www.kingbright.com

USBasp is a USB in-circuit programmer for Atmel AVR controllers. It simply consists of an ATMega48/ATMega88/ ATMega8 and a couple of passive components. The programmer uses a firmware-only USB driver so we don’t need any special USB controller is needed. (source http://www.fischl.de/usbasp/)

So i created a clone keeping all the part count and designators the same however changing the PCB to be easy to etched at home

Features

• Single Side PCB ready to be etched at home (4 jumpers)
• No SMD components
• Added an ISP6 connector (the original ISP10 remains)

Photo

Programming
In order to program the programmer using avrdude work try the following


avrdude -c avr910 -P com3 -b 115200 -p atmega8 -B 1 -U flash:w:usbasp.atmega8.2011-05-28.hex
avrdude -c avr910 -P com3 -b 115200 -p atmega8 -B 200 -U hfuse:w:0xC9:m -U lfuse:w:0xEF:m


Schematic and PCB
Schematic
PCB

Intel MCS-51 (aka 8051) was developed by Intel in 1980.

Somewhere in 1985 one of Intel engineers created a BASIC interpreter for this processor
and the fun just started.

One of my boards with the absolute minimum configuration…

• Atmel 89C52 (8052 clone) burned with the MCS-51 Basic
• 74LS373
• 62265 aka 32Kbytes memory. YES this is 32768 bytes of RAM

You connected the power press space 2-3 times and the familiar basic prompt showed up

Commands:

• PRINT MTOP: Printed the maximum available memory of the system (32768 bytes)
• The second is an Easter egg from the developer of the MCS-51 basic

To be continued…

Last update: 01/12/2011

It is split in two or if you add the power part 3 PCB

Display Board
4 Common Anode Seven Segments multiplexed
IDC 14 connector to the main board
2x3mm LEDs

Logic board
ATmega168
ICP 6 pins for the In system programming
IDC 14 connector to the Display Board
DS1307 with the CR2032 coin battery

Buttons
3 Button for the operation
Minutes Up
Seconds Up
Mode

Mode is selected beetween
Clock
Date
Timer Set (with the Minutes UP, Seconds UP)
Timer Ready (start with the Minutes UP, stop with the Second Up)

BOM

DS1302
2x22pf
32768 Hz Crystal
ATMega168
2x22pf
1x16MHz Crystal

4xSeven Segment displays

Code

History
Somewhere back in time (i think it was 1997) Atmel started the family of AVR processors, small RISC based, easy to program and cheap.

The first evaluation board i used was the A96021000C (AT89/90 series flash micro controller kit). To be honest i bought it because the AT89S8252 was a 8051 core with ICP/ISP programming , OK i bought it for programming the AVR processors me laughs.

On the same year the Atmel released the famous AVR910 In System Programming based on a AT90S1200 (obsolete now) (original atmel pdf) (local copy)

Finally the vendor himself has released all the information you needed in order to create programming boards on the cheap.

The years has passed, and internet grew to a huge number of sites but we still cannot find a way to manage all the information we need in order to create something. Everybody has a different opinion, a new design and so on, this is something i don’t like, but on the other hand some times i do the same (take this page as an example). That’s why you are reading this instead of some links to different sites.

The information should be organized and I am trying to do it with the page that you are reading.

It is the same reason why the arduino succeeded which is based on AVR, more on that on a different page.

Standardization -> Hardware
What Atmel did from the beginning was to standardize the method of ISP that they will use on their family, and the famous ISP 10 pins was born.

ISP Connector 10 pin and 6 pin

On the new designs they suggest that you use the 6 pins version.

Standardization -> Software
Atmel has done it again with the release of the AVR Studio. One program to rule them all.
And all means all their boards, and all their processors.

On the other hand again for all the linux guys like me their is avrdude.

Schematics
The board is based on the work of Klaus Leidinger with a couple of changes.

Change list:

• Redesigned using Altium Designer (not big deal).
• Small PCB ready to be etch at home.
• It has 2 ISP/ICP connectors, one is the standard 10 pin the other one  is the new 6 pins. (Important for me at least)
• TTL to RS232 levels is being done using a Dallas/Maxim DS275 (Yes, it works without issues with laptops and USB2serial converters)

The schematic is self explanatory.

• A small power supply arround  the 7805 in order to convert the input voltage to 5V.
• 2 different connectors
• Crystal with the capacitors
• DB9 connector
• Power/Program LED

AVR programmer schematic

PCB

The PCB dimensions are 7×5 cm. It is designed in a way to be etched at home. The are only 3 jumber wires, 2 on the top and one in the bottom.

Jumbering the 2 pin header enables programming for the programmer from a different programmer (I am not 100% sure that this expressions exists in English, it is the best translation from the Greek language)

AVR Programmer PCB

Compoments Placement

AVR Programmer Photo

Software

You can use the programmer with avrdude. This is what exactly i am using. Have in mind that the baud rate is 115200 bps firmware. The firmware is from Clauss.

In order to make our life easier use this version of avrdude 5.11 Patch 7610
avrdude-5.11 with an updated avrdude.conf for this programmer.

In order to program your devices you could use the following standard ISP/ICP cable. I admit i forgot to add a ZIF socket my bad.

IDC Header 6 pin

IDC Header 10 pin

BILL OF MATERIALS

Total cost around 10 Euros.

Programming the ATTINY2313

You need a ATTINY programmed for the programmer (chicken egg problem), if nobody can program the chip for you send me an email and we will find a solution

Correct fuses for avrdude (example command line):

avrdude -p attiny2313 -u -U lfuse:w:0xed:m

Operation

• Power up the board. The LED should go from RED to Green.  If not remove the power and start troubleshooting
• Connect the DB9 with a straight cable to your PC comm port and check with avrdude that it can speak to the board. The command line is: avrdude -c avr910 -P com1 -b 115200 (replace com1 with the correct com port)

Complete ZIP file with the above

Plans for Version 2:

• Make it USB ready
• Powered from the USB
• Add a 20 pin ZIF socket

References:

ATMEL original version

Last update: Apr 2012

I have started using it for my AVR projects but i came across on some issues so i compiled a COMPLETE list of what you need to do it, in order not to search again for the obvious…

Programmer used AVR910 (or compatible) with avrdude. In the avrdude commands I assume that the
programmer is AVR910, COM port=COM3 and baud rate=115200. Adjust to your programmer.

Have in mind that you might use also -x devcode=0×35 for AVR910

ATMEGA8

The default fuses of ATMega8 are (pdf and locally tested):
High Fuse:      0xd9
Low Fuse:       0xe1
Lock:           0x3f

Programming the bootloader. Chip erase (-e maybe needed in some cases)

• Unlock the bootloader (TEST: try with -e)

avrdude -c avr910 -P com3 -b 115200 -p atmega8 -U lock:w:0xff:m
(fails with avrdude: verification error, first mismatch at byte 0×0000 0xff != 0x3f)

• Program the fuses

avrdude -c avr910 -P com3 -b 115200 -p atmega8 -U hfuse:w:0xca:m -U lfuse:w:0xdf:m

• Burn the bootloader (TEST: try with -D disable auto erase)

avrdude -c avr910 -P com3 -b 115200 -p atmega8 -U flash:w:ATmegaBOOT.hex

• Lock the bootloader

avrdude -c avr910 -P com3 -b 115200 -p atmega8 -U lock:w:0xcf:m
(fails with avrdude: verification error, first mismatch at byte 0×0000 0xcf != 0x0f)

But it works….

ATMEGA168

The default fuses of ATMega168 are (pdf and locally tested):
High Fuse:      0xd9
Low Fuse:       0xe1
Lock:           0x3f

Programming the bootloader. Chip erase (-e maybe needed in some cases)

• Unlock the bootloader

avrdude -c avr910 -P com3 -b 115200 -p atmega168 -U lock:w:0x3f:m

• Program the fuses

avrdude -c avr910 -P com3 -b 115200 -p atmega168 -U hfuse:w:0xdd:m -U lfuse:w:0xff:m -U efuse:w:0x00:m

• Burn the bootloader

avrdude -c avr910 -P com3 -b 115200 -p atmega168 -U flash:w:ATmegaBOOT_168_ng.hex

• Lock the bootloader

avrdude -c avr910 -P com3 -b 115200 -p atmega168 -U lock:w:0x0f:m

And now the good part:

Once you burn the bootloader to a chip you can use this excellent program to upload any hex file to your ATmega with Arduino uploader

References

• http://www.arduino.cc/en/Tutorial/Bootloader
• http://arduino.cc/en/Hacking/Bootloader
• http://arduino.cc/en/Hacking/Bootloader?from=Main.Bootloader
• (settings based on http://arduino.cc/en/Hacking/Bootloader?from=Main.Bootloader 09/01/2009)

Updated: April 2012

I desided to make my own divx movies and i realised that i must have a couple of masters and a Phd to do so )

So i desided to write my own howto.

What you will need:

• DivX Codec (use 5.2.1)
• MP3 Codec
• DVD2AVI
• vfapi-converter
• VirtualDub
• DVD Decrypter

HOWTO

1) Rip it with DVD Decrypter (about 10-15 minutes).

2) DVD2AVI (VOB to AVI convert)

Open the first vob. It will automatically load the others.
Do a preview (Press F5) and write down the file info.

Options: Audio –> Track Number 1
Channel Format –> Autoselect
Dolby Digital –> Off
MPEG Audio –> Off
Use only FILM95 Option if FILM95 is available in preview.
Save the project (about 5 minutes).

3) Audio (ac3tool)

Open the dvd2avi file created on step 2. Lunch Analysis. (about 30 minutes)
On the AC3 to WAV tab change the “Main level” to +10db (recommended)
Process…
4) Create the avi file for Virtual Dub (vfapi-converter)

Open the DVD2AVI file from step 2 and press convert.

5) Get the subtitles (Virtual Dub + vobsub filter).

Open Virtual Dub.
From the filters menu add the vobsub filter.
Open the ifo file of the movie from step 1.
Select the subtitles you want. Press “i have stripped the source files and cross my fingers”
Fade in/out recommended 200ms
Select smooth image
6) Calculate the proper bitrate to fit on 2x74min CD (Advance Bitrate Calculator).

7) Divx Compression + Resize + Subtitles (VirtualDub + vobsub + null transform + resize filter)

Crop the black bars.
Resize to 720×304.

VirtualDub (Full process using mode for audio and video)

9) Split the AVI

Either use Virtual Dub or avi split That’s it. More details soon. Need help ? Mail me

Dallas DS2250/DS5000 Evaluation Kit

Dallas Evaluation Kit Version 2.0. This kit is a MUST for everybody you wants to start working with the 8051 microcontroller.

Specifications

• 8051 core at 11.0592 MHz (16 MHz max.)
• 32KB of NVRAM
• 32 I/O lines
• LCD Connector with contrast abjust
• 2xRS232 Interface. One connected to the DS2250
• Eurocard Connector (dimensions 10×15) with 96DIN connector on board

PDFs and documentation for the Dallas DS2250 Evaluation Kit
You can also download the datasheets for the
DS2250,DS275 and for the MAX232

It used to be a Cisco powered Home (well almost) ))

I have setup a home network and i am always trying to improve it in order to do my life easier.

Here is my full equipment:

• PC Zotac ION
• PC Intel ATOM D945GGLF
• Toshiba Pro U300
• SparcStation 5
• XBOX 360
• A Cisco 1600 Router
• Lafonera 2.0n
• Lafonera
• LinkSys WRT54GS Access Point
• APC SmartUPS 700VA

Full Specifications

• Linksys WRT54GS (the gateway)

DD-WRT 2.4 (i used to pay for the Sveasoft Talisman=> not any more)

• PC Intel D945GCLF (the fileserver)

1 GB RAM
2x80GB (RAID1 for the OS)
2x1TB GB SATA HDD
Powered by Debian 6.0 (tested also with Windows 7. Experience index 2.1

• PC Zotac ION

4GB RAM
1x250GB SATA HDD
Powered by Windows 7

• Toshiba U300 Laptop

3 GB RAM
250 GB SATA HDD
Running Windows 7

• Cisco 1603

IOS Image c1600-k8osy-l.122-5.bin
16MB RAM
16MB Flash

• SUN SparcStation 5

microSparc running at 70 MHz
64 MB RAM
9 GB HDD
Plextor 32x CDROM in an external SCSI cabinet
Powered by Debian 3.1 SPARC

AVR based (completed)

• AVR Programmer an AVR910 clone
• AVR USB Programmer an USPasp clone
• AVR Clock/Timer an AVR based clock/timer (primary use my UV exposure box)

Running projects (TODO)

• AVR Based LED Dice
• AVR Stepper driver