Since some people have actually been visiting the site and taking the time to post comments, I should pay a little more attention to my blog. I have noticed the bug in the theme that kicks the sidebar to the bottom on the comment pages. I’ll look into it soon.
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My circuit boards arrived, and they are beautiful! The quality on these boards is outstanding. I will definitely be ordering through DorkbotPDX again. You can see that the cuts are perfect (with small, perforated, easy to snap tabs!), the trace, drill, soldermask, and silkscreen are perfectly aligned, both front and back.
So, why the odd title to the post? See if you can spot what’s wrong with these pictures:
Yes, that’s right; the fab house made them exactly as I designed them! (Not how they should have been designed…)
I did measure twice… well, at least on the LaunchPad breadboard adapter… The problem was that I did not do a final measurement check before I sent off the order. In the midst of making things look decent and work properly, I somehow made the LaunchPad end of the adapter 0.1” too wide. The power supply I probably made to fit the extra space and intended to adjust the size before sending, but forgot.
C’est la guerre! I may be able to salvage these boards (lots of empty space on the power supply, and maybe some angled pins for the adapter), but I have learned a lesson: Always double-check the “Final” plans.
(BTW: I will post the corrected Eagle board file here once I fix it. The “mini-LaunchPad” portion will not be included; I’ll post that another time, once it’s proven workable.)
EDIT: Eagle board file (fixed?)
One of the main reasons I wanted to learn microcontrollers was that I wanted to make my own energy consumption monitor. I live in the US, and I have an Itron digital electric meter on my house. On the top of the meter is a plastic optical conduit that goes to an IR LED that flashes once for each watt-hour used. I was hoping to use an IR transistor to read the meter flashes with an MSP430, and pass the info to a host computer (probably an old junk laptop I have). Once I had the meter-reading done, I could start considering weather sensors and appliance sensors to see how they affect the electricity usage.
So, I tried wiring up an IR sensor (one side of a dual-IR phototransistor salvaged from an old ball mouse) and hooking it up as I would a switch on an input pin.
I ran a test program, aimed an old VCR remote at it, and voila! It worked! While still jazzed about this, I took the LaunchPad outside with a battery pack, and taped the IR phototransistor over where the IR flash should be… nothing. I turned on the air conditioning to be sure I was using a decent amount of energy… nothing.
I finally broke out my cell phone camera and tried to see the flashes. At first, I thought my meter didn’t flash. Then, I put the camera up close. It wouldn’t focus, but I could see the flashes (please excuse the noise from the A/C unit):
Too dim for my set-up. I need to either find a more sensitive sensor, change the circuit to amplify the signal (an o-scope would be nice!), or can this idea.
Any ideas? I would love your comments.
On Saturday, gatesphere posted a code on the Four-Three-Oh! forums for a free TI eZ430-F2013 USB stick style development board (+s/h). Well, since “free” translates roughly to: “You must order this,” and I am liking the MSP430 line anyway, I went ahead and ordered.
Since I was paying for shipping anyway ($5-6 for FedEx 2-day, not bad!), I went ahead and ordered a set of three extra target boards ($10), and three more LaunchPads. Sadly, the LaunchPads are backordered.
The other items, however, arrived this morning! I like the LaunchPad a bit better due to the buttons and LEDs, but I’m sure I’ll find a use for the eZ430-F2013. The target boards have a breakout for all 14 pins and an LED that seems to be permanently tied to a pin.
Who knows? This may eventually be the target for my electricity usage sensor. It could, at least, be a handy portable test platform to carry outside with my netbook. Or, maybe a simple little logic analyzer?
Since starting with the MSP430 LaunchPad, I found out about Texas Instruments’ very liberal sample program. They (TI) will send you samples of up to eight line items at a time, with varying quantities allowed of each item (usually between 1 and 5). The samples are free (as in beer); the shipping is free, and they ship FedEx 2nd-Day!
What you see in the photo above are a few samples I’ve received in the past two weeks. They are (L-R, T-B):
- 5 very small SMD temperature sensors (for my home-monitoring project)
- 5 equally small 5-wire touch screen interface chips (might try to get a touch overlay in my parts box working, I’ll probably kill a chip or two in the process)
- 5 232 interface chips (like MAX232) (for my home-monitoring project, etc.)
- 5 SMD adjustable voltage regulators
- 5 5v linear v-regs (for breadboard power supply boards)
- 5 more 5v linear v-regs (different kind)
- 2 MSP430 value-line microcontrollers (like the ones that came with LaunchPad)
- 1 very nice 5v switching voltage regulator module
- 5 3v linear v-regs (for breadboard power supply boards)
- 5 more 3v linear v-regs (different kind)
- 2 SMD MSP430 value-line microcontrollers (for my “Mini-LaunchPad” design)
Obviously, this is an amazing program TI offers. If you are a hobbyist, it’s like a free parts bin. If you’re an entrepreneur, it’s a great way to get parts for prototypes (obviously what the program is for). Give it a try; it costs NOTHING.
My tinkering was featured on Four-Three-oh!
I’ve been playing with the MSP430 Launchpad recently, trying to teach myself how to use microcontrollers. The Launchpad is great! USB flash programmer, emulation, demo platform, and a break-out board all in one. They even supply two (slightly different) MSP430 DIPs. All that for US$4.30 (if you can wait; demand is high).
I wanted to connect the LaunchPad to a breadboard to use a few more LEDs than those on the board. I started out just using jumpers, but then my OCD kicked in… I made the prototype connector board in the photo above out of some perfboard and male headers (i put female headers on the LaunchPad). It transfers all 20 pins from the breakout board to the breadboard (even though I only have 14-pin MSP430s). Lots neater than separate jumpers, and it connects the boards physically pretty well, so I don’t have to worry about knocking a connection loose.
Then my OCD kicked in again… Why not do a printed circuit board? So I set to learning Eagle CAD. Eagle is pretty good, but the initial learning curve is fairly steep. Luckily, there are several good tutorials on the internet.
The resulting design is pictured above. I’ll write more (and post Eagle files) when I get the boards (near the end of the month).
Thanks again to Four-Three-oh!
A great (and funny) talk about how modern education is not set up right for our kids:
Thought I’d change the theme for Christmas. It’s only temporary, so some stuff may not look quite right until the new year.
Happy Christmas to you and yours!
Thanks for dropping by!
Well, I decided to try the “Camp-out for Black Friday” thing again (see previous shenanigans). This time, I showed up at Sam’s Club at 6:30 PM on Thanksgiving. I went prepared, with my iPod full of podcasts and movies, a newspaper, a sleeping bag, snacks, and my cell phone. Unlike my previous attempt, there wasn’t a huge crowd. As a matter of fact, I wasn’t technically “in line” until 12:30 AM when the second guy showed up.
We chatted through the night. When the police drove through, we joked that they had showed up for crowd control ;-) Number three in line didn’t show up until about 3:00 AM (yes, I could have stayed home most of the night!), but by 5:00 AM, when Sam’s opened, there were about 50-75 in line.
There were only a few items Sam’s was short on, but they did run out of the item I came for. (I will refrain from naming that item, since my kids are among the six or so readers of this blog.) I was checked out of Sam’s and on my way home by 5:05 AM.
Was it worth it? Sure. The item I wanted was selling out everywhere and, while Sam’s did not have an exceptional deal on it, it was worth it to know that I have that item for Christmas.
Happy Christmas to all.
Not sure how many read this, but please do what you can to save this dog:
http://www.getfreshminds.com/2008/10/baghdad-pups.html
Thanks,
Doc
