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Topics - znanev

1
Flash_Destroyer EEPROM tester / Free PCB build + EEPROM written to death :)
I started building the Flash Destroyer after I received the free PCB, but I had to put the project on hold due to some other high priority tasks and lack of some of the parts :)

The most expensive parts of this project were the 7-segment displays. I had a lot of different 7-segment displays in my junkbox, but most of them are not single digit. I didn't want to spend about £1 a digit for Kingbright's displays, so I headed to eBay for a quick search. I found these for about £3 shipped for 10 displays:

http://www.ebay.co.uk/itm/NEW-10-X-0-56 ... 335bfba94c

The part number of these displays is SM42056-1K and according the datasheet they are suitable replacement. These displays are a little bit taller and wider then the Kingbright's, but eventually fitted nicely on the PCB :)

After the PCB was built, I plugged the poor 24AA01-I/P into the socket and turned the power on.

This picture I took the moment I turned the power on, but due to my slow reaction and the shutter lag, some 500 cycles elapsed in an instant:

[attachment=3]

Then I left the poor boy sitting there and counting, counting ...

After 13 days elapsed, the counter was still ticking and the EEPROM survived over 7 million writes. I wanted to capture the precious moment of the display showing all 7s, but again I had no luck:

[attachment=2]

Event though I put the camera in burst mode, the speed was not sufficient to capture the exact moment. The photo before this one captured 7777762.

Then again I left the destroyer doing its job.

After 19 days since the start, I found the poor EEPROM had died:

[attachment=1]

I'm not sure where I got the firmware source from, but it seems it was an older version, because after the 10 million writes the display didn't show a dot but reverted to all 0s again. So in fact the total number of the writes the chip survived was about 11.4 million.

[attachment=0]

After the EEPROM had died, I played a bit with the sources and made the display capable of showing all alhpa-numeric characters (some were not that readable, but it is hard to represent some letters with only 7 segments :)

Now I'm working on re-purposing the Flash Destroyer into a digital thermometer. I will post my success (if any) here soon.
2
DIY Life projects / Free PCB build
About a year ago I received a free PCB and assembled the circuit. Now it works nicely as mood lamp and I decided to share the result.

First, here is a photo of the circuit sitting in a plastic box from business cards:

[attachment=3]

The first version of the "LED pod" I built for proof of concept. It looks really ugly, but did its job:

[attachment=2]

The LEDs came originally in crystal clear packages, so I sanded them with some fine sandpaper in order to make them "diffused" to better blend the different colours. I used 4 Red, 4 Green and 4 Blue LEDs for this proof of concept board.

After a while I decided to make the LED pod a little bit brighter, so I bought from eBay some PCBs like this one:

[attachment=1]

This took me about half a day to build due to the time required to "diffuse" all 24 LEDs :)

From the proof of concept board I noticed the red colour is noticeably dimmer compared to the other two, so this time I just doubled the red LEDs and the new LED pod now contains 6 green, 6 blue and 12 red LEDs.

And here is how the finished mood lamp looks now:

[attachment=0]

The globe is from an Ikea lamp I bought cheaply (something like £5) and blends the LED colours nicely.
3
Bus Pirate Support / Serial to I2C - is it possible ?
Hi all!

Sorry for the noob question, but I am interested if the following scenario is possible:

Control the Bus Pirate through serial interface (using 3.3V RX/TX only) instead of the USB port.

I know the USB port actually emulates a serial connection, but you need a PC for that. What I need is connect the Bus Pirate to a linux-capable router having serial ports only. The router will issue / receive data using its serial interface to control I2C devices.

Even if it is not possible to do it with the firmware only, I am comfortable to modify the board (just a bit :). Is there an easy way to "switch off" the FTDI chip and connect the Bus Pirate board to external 5V power supply and directly to TX / RX connectors of the router (3.3V)?

Many thanks!
Zdravko