Archive for the ‘Electronics’ Category

Nixie Tubes

September 14th, 2009


My nixie tubes arrived today from Russia. Trying to decide what to make with them. Any ideas? The one on the left displays numerals, and the one on the right is bar graph. I have 10 of each. I was thinking of perhaps a 10 channel spectral analyzer for my stereo with the bar graphs. A lot of people make clocks with the tubes on the left, but that seems almost a bit too generic.

Electronics ,

Stepper Motor Controller – USB interface

September 1st, 2009


I just finished designing a Stepper Motor Controller (SMC) for a PCB Mill that I ordered. One requirement most SMCs have is the need for a real-time operating system running only the milling software. This is because each motor movement must be timed precisely to ensure an accurate rate of movement from the milling head. If other software is running, then the timing of the interrupts can be off resulting in errors on the mill.

Not wanting to use a dedicated computer, I decided to design a bipolar chopper controller for myself. The big difference with this device and other controllers is that you will be able to feed it g-code directly, and not worry about controlling the timing. The processor onboard will be able to deal with the timing requirements and it should work. Some features include :

  • Send g-code directly via USB interface (linux/mac/winblowz drivers), does not require dedicated PC
  • Software controllable current (chopper mode) (1.5A/motor max)
  • 3-Axis on small PCB (2.9″x2.2″)
  • USB interface, powered off USB except for motor.
  • Over-temperature monitoring

If there is any interest, I’m happy to release the designs to the public domain.

Electronics , , ,

CO2 Sensor Distraction

August 21st, 2009

Many hours ago I got sidetracked and decided to build a “quick” Carbon Monoxide (CO) sensor interface. The CO sensor is a Figaro TGS 2442 Carbon Monoxide sensor. It ended up taking much loner than expected to build – though most all projects take longer than expected. I am using the module in the bottom of the picture to power the device via a USB connector. The number of LEDs illuminated increase as the CO2 conentration increases. The measured values from the sensor are pretty meaningless as the device must first be calibrated using controlled CO concentrations which I can’t produce at home. As a result, I defined the CO level in my room as 1 LED. The goal is to migrate this circuit into my car and use it to gather geotagged CO data on the road using the car gadget that I recently mentioned.


Electronics, Personal , ,

New project takes life

August 15th, 2009

I just finished a new PCB that I’ve been thinking of making. It’s general purpose car interface. I left a lot of headers on it so I can reconfigure aspects of it on the fly via jumper cables.



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Vista Annoyance: Beep Service!

July 14th, 2009

So I’m having applications of mine beep at random times. Actually, they are both compilers for embedded systems. When I click on a file in IAR and using AVR Studio the computer beeps. It’s really annoying, and it seems to have started on its own as the applications didn’t do that in the past. Well, it seems as if this is a feature. Windows includes a BEEP SERVICE! *grumble* You can find it under the system devices menu if you select view->show all. I turned disabled it and I think that fixed my problem. Whoever came up with that idea needs to be shot till he/she is dead.

UPDATE: this in fact has not solved the beeping problem I experience from using IAR Embedded Workbench. But I am still disabling the beep server.

Electronics , , ,

Video from the BSN2009 talk is online

July 6th, 2009

Seems that the talk I gave at the BSN2009 converence is now online. After watching the video, I think I need to spend more time in the gym. The video is in some windows streaming format, but I’m trying to get a more sane version if it post. For the time being, this link should work..


Electronics, HealthMonitor , , ,

Starting Electrolysis

July 5th, 2009

Setup in action; Old power supply maxed out (~1A @ 6V), bubbles forming and crud appearing…






4th of July & Meat Slicer update

July 5th, 2009

P1020907.jpgI’ve made some progress stripping the paint off the base of the unit. I got a very aggresive wire brush for my angle grinder from harbor freight (not pictured, and and I can’t find the part on their website; came from a kit #90976) and that seemed to do a great job — though it litterally rips the metal and paint off together. I’m not sure how much “sanding” I’ll have to do get it smooth enough for painting — nor do I have a clue how to paint it yet. My best guess so far is to get some spray epoxy for appliances, though I’m uncertain how the finish will be. Powder coating is another option, but that might be expensive. There’s some more stuff I have to remove to fully strip the paint, but I’m not sure how yet — it’s a bit of a puzzle figuring out the order of parts to remove.


So tonight was the 4th, and I felt as if I was in Iraq. Lots and lots of explosions all over the place. People launching fireworks at each other in the streets. Kinda fun, very dangerous, and pretty stupid. After setting off explosives for the longest time, the cops finally decided to arrest this one guy in my hood. Then 11 cop cars showed up. 11. Not sure what they wanted to do, but they just hung out. They managed to block a bus, whos driver was too stupid to drive around them (not electric one so they could drive on different streets). She’s in the middle of the photo trying to get the cops to move so she wouldn’t have to go around. And she was so rude and unprofessional in how she treated the passengers. It pisses me off how much protection they have with the unions — they know they can’t get fired so they treat everyone like shit.

Electronics , ,

Restoring 1940’s Hobart Meast Slicer

June 29th, 2009

I picked up a 1940s Hobart Meat Slicer from some salvage store in Berkeley for $120 last week. It was a mess so I’m the process of stripping it all the way down and restoring it. Part of the process is to remove rust from various parts, and to that end, I’ve fabricated a rebar based de-rusting electrolysis setup based on information from here. I’m waiting for the washing soda (used as electrolyte) to come in on Thursday, but it looks kinda neat how it’s been setup. I got 6AWG wire, which is overkill (for use up to 50A) but it adds to that industrial look that I like

Electronics, Personal , , , ,

BlackCloud Red Version Complete

January 22nd, 2009

note: REDACTED stuff as requested by lawyers

I’ve finished writing the firmware and testing out the hardware for the latest version of the blackcloud device. I called it the red version, as the box it will live inside is going to be red. Yes, I’m quite creative. The LEDs are also all red, a mistake at the manufacturing house. *sigh*

This is the first design I’ve made that runs on Ethernet (10/100mbit). It uses the [REDACTED] module, which worked out fine. Though the Ethernet jack was a bit more difficult to use — I didn’t realize that I had to get a specific plug to support PoE. I’m using the [REDACTED] switching regulator in conjunction with a [REDACTED] to simplify the connector requirements for the device. I followed the recommended design which requires some big honking caps on the board — but it also looks really neat. Greg and I are both fond of the [REDACTED] inductor. It just looks nice.

The firmware had a few hiccups, which took awhile to debug given [REDACTED] is a sucky combination. I used to be such an avid fan of gcc for embedded design, but after using IAR for awhile, I got spoiled. What can I say.

This version features an [REDACTED] temp/humidity sensor and a new light sensor, along with the Ethernet interface and power supply upgrades. Oh, and we’re switching over to a much quieter fan as well. I’ll be delivering one of these guys to someplace in south Africa shortly. Should be entertaining.