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Everything posted by username

  1. For hobby use with low pin counts, yes, always G2553. For commercial use or if more pins are needed, I go with freescale MCUs or whatever i'm forced to use. Yes, I likewise hate the arduino 5V... 3.3V is fine for me in every application even in low power.
  2. Very cool that you were able to implement a stable workaround. I can't remember, did you by chance get your sensorless algorithm working? Do you have a video by chance? XD . When I did mine I used Arm core to have a bit more beef & filter options. This was a dev board I made for it, not meant to be tiny. I'll post a video hopefully in a couple days on it but i'd be awesome to see your implementation working as well.
  3. It could be me failing at driver writing but I do all my drivers from the ground up in CCS(starting usally with the TI example code). Never touched energia. I've heard of work arounds to get glitchless opperation of TI MSP430 PWM pins but most of them involve waiting. With a BLDC sensorless algorithm, there is no time to wait and all PWM generation must be %100 consistant to reduce jitter.
  4. Hey all, Been awhile since i've posted something. Here was a small portable 2.4GHz transceiver(CC2500) that I made. This can operate via battery or USB power. USB charges the battery. Has reverse + UVLO + OCLO protection (hence all the transistors on the right portion of the board). Here is a closeup of the RF chain. I used an integrated balun to reduce component counts. I use a 0603 tripad to switch RF output between SMA & chip antenna (unpopulated in pic). I used a coplanar waveguide as a TL. System seemed to be fairly efficient. I get 2.4dBm output power when using the 0 dBm p
  5. MSP430s have glitchey PWM operation. I wouldn't recommend them for this application. A large dev effort would be to get ideal operation out of the PWM pins which ideally shouldn't be your focus. Feel free to chime in someone if i'm mistaken.
  6. Seems like everyone has their own 3D printer. Here is the one I got for ~330 USD. I don't need any real fancy performance. Just need basic boxes and stuff. http://www.ebay.com/itm/Folger-Tech-Prusa-i3-RepRap-Full-3D-Printer-Kit-w-Clear-Acrylic-Frame-/231301357105
  7. This is huge news. Kinda scares me. Freescale struck me as a lot more innovative and bleeding edge where as nxp was expensive but had decent documentation(and not bleeding edge forsure). I hope all the freescale products don't double in price over this. I'm guessing we may see a few counter merges as a result of this. ST & TI?
  8. username


    Basically a new cosom/xively? Looks like a great interface with a good feature set. Very impressive. Best of luck with the site! I'll certainly keep it in mind when I run into another streaming application/project. Somewhere near the bottom of your homepage for non logged in users i'd recommend adding that pricing table. Some people won't bother registering unless they know beforehand the model of the site. Edit: Also not sure why but the login button doesn't work for me. Using firefox but it may be a adblock/firewall issue. Signup worked fine. Once I logged out I couldn't get back in.
  9. Hmmm.... in the spirit of 43oh you could make 229 balls of fire demonstrating your fierce loyalty towards the msp430
  10. I'm kinda creeped out by where I moved to as well and was going to do the same thing. I'd use PIR modules and ultra sound modules and have a few different nodes across my house using the NRF 2.4ghz modules. Wireless receive is expensive in terms of RF & current. I'd have a powered hub thats always in receive and have sensors that transmit every 1 - 10 seconds. This method amounts to uA of current usage average for the radio. If ~2x messages are lost or a breach message is sent, have the alarm trip. Sensors would be battery powered and need a recharge every 1-2 months. Would use a lithium
  11. You could create a CPU with 229 cores! You could put Intel i7 quad core to shame! Should only take a week or 2 to make. Edit: Or you could blink like 229x~30 LEDs!
  12. Hey guys, Glad to hear you guys got your controllers and hope they work well for you! Europe VAT tax is a beast. Sadly I can't legally mark them as a gift . US has no VAT but it has some of the highest business taxes. Social services / entitlements are very expensive . Not to get into politics but be careful what ya vote for.
  13. Happy to see it back up, thanks for maintaining the site!
  14. If you bought an off the shelf weight scale those usually have force sensors(load cells) in them. However, you would risk going over their rated limit with a full couch weight (even divided by 4). Furthermore, they are probably not designed to have constant weight on them. While this may be a bit difficult / awkward, if you had a webcam/camera pointed at the couch you probably could write an image algorithm to detect your dog. Or, if there any internal points in your couch that compress based upon weight, you could use some type of sensing systems internally and trigger for small changes
  15. 3 hr to build and looks great! Note, you can download instructions on RobG's Tindie page and they are quite nice! Thanks RobG
  16. As I said before and ill say it again, datasheets not dogma but marketing brochures. You can debate datasheet specs all day but it doesn't necessarily reflect reality. After you encounter couple 100-1000 parts, you learn that datasheets are frequently wrong in some areas and are significantly mis- represented in others for the sake of sales. For example, If you have the tinniest bit of ripple on your supply, or are not in a fully anechoic temperature/humidity controlled vacuum chamber(on the ISS), you may very well see results differ by 10-100x. I learned this after I dealt with a product that
  17. Low power is a fun nut to crack. The current usage figures in datasheets are generally marketing figures. I'd be best to grab a dev board for both processors your interested in and play around with a uA meter and the software features you know you need. Keep in mind that RF usually requires a decent amount of power for any type of range. Powering the processor may be peanuts compared to completing a transmission with any decent range.
  18. awww this makes it harder to use the additional shocking features none the less, please take my money
  19. 1MHz clock makes math easy, no other reason. Yes the mosfet can generate a 5V pulse with the circuit shown. Yes, you should be able to port this to other MCUs though if their core clocks are different you may have to tweak the math to get the proper distance.
  20. The trig pin on the module wants to see a 0-5V digital input. The msp430 only has a 3.6V input max. That mosfet works as a 3.6V to 5V converter. Since its a 5V module I did this to be safe though i'm not sure its required. It might tolerate lower voltage inputs. Use any basic mosfet that can handle a 3.6V gate voltage. A 2n7007 is a basic FET that should work. As for how a mosfet works, see wikipedia. If your asking as to how the trig pin works on the module, see the module datasheet.
  21. Hooray! can't wait! Is the power board needed for the clock kit or is that already onboard?
  22. username

    DAC GUI V2

    Sorry biotech, C# does not have any native way to enumerate the friendly names of ports that i'm aware of. Consequently i'm mining a win32 register to get this information. I'm guessing thats why its having issues on wine. I'm using something very similar to this post: http://www.creativecodedesign.com/2010/03/14/how-to-get-friendly-names-for-com-ports-in-c/
  23. That makes sense though there is a HAM test question that seems to conflict with that: "T3A02-2014: Why are UHF signals often more effective from inside buildings than VHF signals? ", answer: "The shorter wavelength allows them to more easily penetrate the structure of buildings " Wouldn't it be opposite of that?
  24. So true, small ground planes(in comparison to wavelength) combined with a 1/4 monopole antenna destroys efficiency. Hence why if your in the ~433mhz | ~900mhz band, you either need a large gp on your transmitter or your going to have to have a verrry efficient receiver in order to get decent distance. Having low buadrate & long pre-ambles can help a bit but a course its a tradeoff. It is much easier to make efficient 2.4ghz monopole transmitters which is why their range can be very comparable with 433 & 900 mhz systems.
  25. Neat man! Verrry cool. Love the droplets XD . Yea, from the RF side was gonna ask how you made your 50 ohm traces, how you planed to verify your discrete balun was working, and how you were going to impedance match. That picture is abit blurly so can't confirm ya did a discrete balun. I'd recommend using the one already designed for the cc11/cc430 915mhz version. Only way I could think to do balun verification would be with a high freq scope? However, thats only if ya want max power output. If you can get your hands on any type of spectrum analyzer you can use guess & check by looking at
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