Hello, I’m Ketturi Fox, and I’m addict. Yes, I have VFD addiction, Vacuum Fluorescent Displays, I mean. I have big box of them, waiting for appropriate project (which probably will never come). This time I found big nice displays from old digital scale.
Category: Electronics
Inside crystal
I found an old crystal oscillator from my junk bin, and tough it would make interesting teardown. It is much bigger than new ones, but it works just same way as its little brothers.
Shall we look inside? Read More …
Was this uploaded yet?
Can’t remember if there are any pictures showing ~ready sate. Still ticking accurately. Could add more functions and maybe battery backup for alarm, but it is very good alarm clock at now so might be left as it.
Programming xmega with usbasp & avrdude
Few days ago I got package from Helsinki Hacklab. Some generic component stuff and a couple Atmel xmegas and breakout boards for them.
Nice bit more powerful MCU’s than normal atmegas & attinys, but they eat only up to 3.3v, so better not to kill them with 5V logic. Luckily most 5v logics detect 3.3v as high, and their higher output can be lowered with resistor divider. Programing these xmegas also differ from their li’l brothers. Xmegas use PDI, which is kind of two wire system, constant clock signal and data I/O. I did not have expensive atmel programmer, so I improvised cheap ~2€ programmer using usbasp and avrdude using these patches. Read More …
Unitrex 1200 and lesson
Yesterday I found an old calculator from e-waste center, which caught my attention. At first glance I knew that this was not ordinary VFD or LED display desktop calculator. So I stuffed it into my bag and scurried back to home with my precious find. At home I plugged the calculator into the wall socket, which I probably shouldn’t have done. Of course it did not work. But no worries, what could I could not fix? Read More …
Nixie clock firmware
Firmware for clock is in publishable condition at last. Now all major functions are implemented and no bugs are (yet) found. But there will be likely future versions with slight fixes and features. And yes, it is made with basic, terrible, horrible and not 1337 at all, but it was easier and I could ask help from friend who have similarly constructed clock. There is also slight chance that I will translate this to avr gcc, but it would be big job, because it have not all functions and stuff. Read More …
3×4 Keypad
Keypads are easy way to input information. I made one from old electronic calculator, and it may be used in SID synth.
Read More …
Dual buck converter
I had boring day, and was too lazy to do school works, so what else I could do but electronics? For next project I need power supply and due to poor efficiency of linear regulators, I choose to make an another switching regulator.
And there is the blurry picture. Similar construction to the nixie clock’s power supply, but this time double. Read More …
Vintage 7-Segment displays
I found some old HP/Agilent LED displays. They are common anode type, and have DIP 14 packages. I haven’t seen these before in real life, and I think these are beautiful little displays.
Nixie-clock update
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- Hole for ISP connector
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- Power and ISP connector
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- Glued to backplate
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- Bodged wires and not so good soldering.
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- Changed some connectors.
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- Nearly finished
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- Switching regulator PSU
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- IC pinched to between board and metal for spreading heat
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- Nixie tubes.
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- Ditto.
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- Tubes and controller board
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- Mobo
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- +170V PSU
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- Still missing front panel texts.
Itty Bitty Buck converter
Everybody knows old 78xx linear regulators. They are ok for many applications, but are problematic for bigger currents. They drop and regulate voltage smoothly for circuitry, but because all excess voltage are dissipate as heat, they are very inefficient. For my nixie clock I needed efficient little power supply for 5V rail, so I created this little baby:
Look how cute it is!
SyncMaster 245b repair
A week ago I found Samsung SyncMaster 245b 24″ LCD monitor from trash. I tested it and it did barely power up. Blue led lighted in power button but nothing else. From the beginning I suspected powersupply, because its most common problem with LCD TVs and monitors. I opened display and started to examine the patient. Read More …
I feel so stupid ಠ_ಠ
Now I know why I2C was not working in my nixie clock. Today I got an arduino nano from helsinki hacklab, and started to troubleshoot my circuit. Oddly RTC worked when I tried it in breadboard, and also in clock’s motherboard, when nothing else were connected. Also noticed that when nixie driverboard was connected, both of the i2c lines had weird resistance to 5v and ground. I once again removed driver board from case and measured. It was ok, of course. I didn’t even tough about cabling <.< Read More …
Flashing monitor EDID
Yesterday I got a HD4850 card from post and happily installed it to my desktop computer. I noticed that my 15″ secondary monitor was not detected, but I ignored it until today. Working with two monitor is so much easier and faster, so I started to investigate problem. Read More …