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tonesenna

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Everything posted by tonesenna

  1. I attached the design files for this initial version of the rocketfuel. You are free to copy, modify or use it any way, although a reference to the original work would be appreciated. Prototypes mounted and first tests already done. The charger circuit has one flaw: the body diode of the P-channel MOSFET creates a current path that lets current flow from the battery into the state LEDs and even the charge controller's supply pin. In practice, we see both leds dimmly lit when the USB supply is removed. This can be somehow circumvented by removind one of the LEDs - the DONE LED, leaving
  2. Good news! :mrgreen: Remaining parts arrived today. I have 3 boards assembled, except for the stacking headers, which I'm still waiting to arrive by normal mail. Since the sparkfun batteries are also still on transit, I am using an old BL-5B Nokia battery, soldered and soldered wires on it for a quick test. So far everything looks good. Both the battery and the pass transistor are running very cool (although I'm not sure if the charger is already in CC phase) :thumbup: It's kinda late so no pictures or test results right now. On the weekend I'll grab a few photos and do some testing.
  3. I discovered 43oh quite recently and had very little experience with the previous forum. As for the current implementation I wouldn't say it increased or decreases my commitment to the forum. The same goes for user experience. For me the main driving factor is the community. The role of the forum software is important in the sense that is doesn't get in the way. I guess that's true for both incarnations. As for site administration, if this version improves management, filters malicious bots/scripts/whatever and allows more feafures efficiently, that's seriously very cool!! :thumbup:
  4. On one hand it's sad to know that the store is soaking so much of yout time and effort in such a way that you need to tap the brakes to avoid letting things go out of control. On the other hand it is very nice to know that you managed to build such a significant community around 43oh and the interwebs as well. Congrats for that. I really hope you can sort out a way to run the site and store and, also important, take due credit and compensation for all the effort you're investing on the project. -- to
  5. Hi everyone, I am in the process of evaluating which tool might be more suitable for the design of relatively simple boards. From the alternatives that I found, diptrace and eagle seem to be the top contenders. These are clearly tools not intended for complex jobs, although they can get the thing done for a fraction of the cost of more capable tools. I think eagle has a cumbersome way of defining the coverage of vias with soldermask. The management of component libraries would be better if eagle had an automated way of updating a landpattern accross all libraries that make use of it.
  6. The PCB prototypes arrived today. These units come green. However I plan to make them red on the final version. The PCB quality came quite good in general, although there are some quircks: some drills are slightly off-centre. This can be noticed specially in vias, althouth it's effect is mainly cosmetic There is no soldermask on vias. I have to check the PCB design to fix this silkscreen clearance to copper seems too small apparently. The silkscreen got truncated around some SMD pads, which I wasn't expecting. Need to review my landpattern library. Some placement drills are plated, al
  7. I second pagibot. In a way, any language is unsuited for a particular purpuse if used inappropriately. All those items are generally known as coding/design flaws, regardless of using C, C++, java or any other language. The question at hand is not if there are people that know C++ and if these people have the skills to code for an MSP430 in C++. The question is about the possibility of using the features of C++ (only the ones that make sense in an embedded world) to code for the MSP430 without compromising performance and code size. I guess oPossum's links above depict that quite well
  8. I, for sure, would like to be enlightned on this matter, as it does seem to contradict common kowledge regarding the MSP430 architecture. I believe that C++, properly used, may be effectivelly used to reduce coding effort and keeping the generated machine code as efficient as the equivalent C would. It comes to my mind that using templates to code for several implementations of an USCI driver might accomplish that, with a single template one might easilly implement, for instance, an UART on all USCIs of a given device. -- to
  9. It depends on the device and the supply voltage applied to them. Typical maximum frequencies are 8, 16 and 25 MHz. The best to do is actually check the datasheet for the particular device that you're interested in.
  10. After many iterations the PCB was *finally* :mrgreen: sent for fabrication. This is my first experiment with a PCB prototype so... fingers crossed. The prototypes will be green although I'd like to make them red if they happen to spark the interest of the community. Here's a peek of the final (yup, really) design: The boosterpack takes the battery on top to minimize stacking height. Components on the solder side were kent away from obstacles (DIP package, jumpers) to minimize stacking height to the least possible. There is a 1x2 female header located matching with the VCC conn
  11. Last minut changes... The original idea was to place the battery beneath the PCB. However, when stacking the RFBP with the LP, the stacking height was too high and forced the use of staching headers that were way too expensive and didn't allow to stack the RFBP with other boards. So, I'm in thr process of moving all components to the bottom and placing the battery on top. I keep the area of the DIP socket clear so that we can stack boards with only 10mm spacing. This will allow to keep BOM cost down, make the RFBP stackable and make it more convenient to handle. -- to
  12. Thanks! I searched in forum for "C++" and oddly got zero results. I'l follow your hint though. -- to
  13. I never tried this and I could easilly check this for myself. But out of curiosity, I wonder if it is possible to code for the MSP430 in C++. In particular I was thinking of mspgcc which is freely available. Has anyone tried this already? Thanks. -- to
  14. VLO , DCO and External crystal are all clock generatores. Which one to use depends on your needs in terms of clock speed, accuracy and power consumption. VLO is a very low power clock that runs in the 10s kHz. While speed is very limited, it provides you a means of having a clock driving some system logic with minimal power consumption. This clock generator isn't accurate at all IIRC. DCO is a high speed clock generator that runs in MHz range. Is requires more power but allows clock speeds magnitudes higher than VLO. Accuracy is tipical in the range of 1 ~2% so it should be ok for appl
  15. It would be nice to have some kind of filter that showed a list of currently unanswered posts, ie, topics with 0 replies. Would such a thing be attainable? Thanks! -- to
  16. Things have been advancing slowly but steadily. I made a major review so that I can source all components from the same distributor. I also tried to improve power dissipation around the pass transistor so that I can keep operating temperature within reasonable limits. So, here it is, hopefully the last design iteration of the rocketfuel boosterpack. Top Layer Bottom Layer Silkscreen --to
  17. Neat!! I never noticed the existence of an 8-pin MSP430. This part may definitely come handy! Thanks for sharing! -- to
  18. Are the bots decoding/guessing captchas? A good question would be one that requires some kind of logic from the user which can't be performed by a machine/script. In practice, though it's not easy to come up with something, specially something that fits into the tools that ipboard provides. One example, would be to select, from a set of objects, the one that doesn't match. The mismatch may be due to colour, number of sides of a polygon, mounting type of a IC package (SMD/TH), type of memory (volatile, non-volatile), prime vs non-prime number, integral power of two vs non integral power, ty
  19. My post is kinda late but I'd like to thank you for the awesome work done with the change to the new forum engine. If I had to suggest something I'd go for the colour theme. Personally I'd like it to have a little more contrast, but its just my taste anyway. Thanks for all your effort!! -- to
  20. After moving the battery to the bottom I changed the whole layout. The battery charger was placed primary battery holder, so that in case I want to build a non-rechargeable version, the non-mounted components stay hidden, for a better visual effect. The PCB still needs test points and artwork. After some review It'll be send for prototyping. I was considering producing the board at eurocircuits. Do you guys have any other suggestions? -- to
  21. Yup, I know the connector's P/N and landpattern. My doubt was related with the pinout itself, Which doen't seem to be documented anywhere. For instance, the 400mAh shows the datasheet here: http://dlnmh9ip6v2uc.cloudfront.net/dat ... 400mAh.pdf On page 10 you'll see depicted a 3 pin JST connector that includes the NTC terminal. However, the product page shows a battery with a 2 terminal connector. I managed to figure out the pinout looking at the pictures on this tutorial: http://www.sparkfun.com/tutorials/241 I don't know if anyone from sparkun reads this forum, but It'd be nice
  22. So, here's a quick update. The shunt monitor was dropped because the dynamic range wasn't good enough to cover the range of possible discharge current. I made a search for an LDO with very low Iq and UVLO to avoid relying on the battery's own protection circuit and stay on the safe side. I couldn't find a suitable part, so I decided to add a voltage supervisor. In terms of low power operation I expect the rocketfuel to behave quite well: LDO's Iq is 8uA@150mA and 0.5uA@0mA Supervisor Iq is 0.5uA @ Vbat=5V BQ2057 BAT pin leakage is 1uA typical Summing all up, the battery drain wit
  23. Thanks blue! Indeed they are difficult to source, specially with appropriate dimensions that would fit the boosterpack design. I'll take a look at these links later and see what I can come up with! Regards.
  24. Thanks for your input blue, lots of contributions there! I totally agree. My first thought was to use a taped battery. I decided otherwise because I wasn't able to find a battery that would fit the boosterpack with a decent capacity (>400mAh) and with high availability. I want to leave the buttons of the LP available so the bottom side of the boosterpack must be trimmed out. Doing rough math (assuming a 40 pin interface), I have an area of 40mm x 55mm beneath the boosterpack where I might stick a battery with double-faced adhesive tape. Do you suggest any website in Europe where I mi
  25. The BQ2057 can handle much larger charge currents, IIRC up to 2A (probably even more because of the external pass device). When running from a USB port however, the current must be limited to 500mA. For higher charge rate we'd need an external power input jack and a wall adapter capable of supplying the additional current. For higher charge currents a switched mode charger might be a better solution. High amperage wall adapters are somewhat rare and probably expensive =) Regards, --to
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