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Everything posted by Lgbeno

  1. @Blurred Talon You might want to check out this thread, there is some discussion about tlc5940 and someone posted some example code http://www.forum.43oh.com/index.php?/topic/3190-How-to-drive-multiple-LEDs-without-sacrificing-brightness
  2. Thanks for all of the input. This would be implementing the very low level control for the motor so it would be a state machine to keep track of what motor windings to pulse current through and then use the adc to sample the back emf and decide when to change states based on this feedback. Then around that I'll wrap a speed loop.
  3. Thanks bluehash, it would be great to get a few bldc boosters out there in members hands. In fact I have about 20 on hand and another 30 ready to bake. I feel pretty good about the hardware right now but still think that firmware needs some improvement. For the processor, I'm targeting msp430g2553 because of cost but certainly a Stellaris or c2000 part is better suited. I'm pretty familiar with the ti designs for instaspin and they are great, I just felt that it would be too costly to base a open source esc off of a high end chip like drv8312. Also when working with my local ti rep, he to
  4. So I'm currently rehabbing my tek 544a scope since it isn't working at the moment. I was just wondering if anyone is aware of a project out there that turns one of the launch pads (besides the msp430) into a poor mans scope. I just want to sample a signal that is scaled to <3.3v at like 100ksps and see what a few k of samples looks like. I could develop myself but this is one of those projects I'd rather not reinvent the wheel. Thanks in advance!
  5. Hi Everyone, I am another one of those rude forum members who have been posting over the last few week without first an introduction. My name is Luke and I've had a lifelong passion for electronics. I studied EE at Michigan Tech and have been working in industry now for about 5.5 years. I see myself as more of a hardware guy but try to be cross functional and develop code as well. My experience is that it is almost impossible to have a great project unless there is great harmony between hardware and firmware. I typically use design spark for schematic and pcb, fab boards at iTea
  6. Be a little careful because with a shift register, you will have to develop code that might be a little more complicated because there is the code to generated each individual led pulse width and then on top of that code that shifts the data into the register. Would that tlc5940 part work for you because with the need to control each led independently, it's probably the easiest and most robust to implement. How did you come up with your budget for current? Do you have a battery selected or a specific size constraint that you are looking to deal with? Also what color led, each one h
  7. Shift register is not required, it is just a nice cheap method for driving many LEDs with a few pins of your microcontroller. The other nice thing is that the output pins of these logic devices have very robust drivers which can source or sink 20ma. For a shift reg though you will need a resistor to limit the amount of current through the led so 16 LEDs means also 16 resistors in parallel. Like I was saying before if you use a higher voltage then you can hook up the LEDs in series and save some resistors but a High enough voltage is required. About 2v per led if wired in series. Since
  8. Hi everyone, I've been working on a project for awhile now which is a open source esc motor controller based on msp430g2553 and developed with LaunchPad. I'm at the point right now where I've written some code in c using ccs and it works decent but like all projects, I know exactly what I need to improve and want to rearchitect and write it from scratch to optimize everything. I recently downloaded and installed energia and I'm curious what the community would prefer so that the design can benefit more people (and also adopt and enhance my code). I want my code to be highly optimiz
  9. Tlc5940 looks like the perfect part for what you need, if you can afford it and are able to write the code, it should be a slam dunk.
  10. So are you looking to control them individually or just have a set of 16 that are all on but dimmable? Do you have any special needs for input power like a battery? I think that the most simple implementation could be using a higher voltage wall wart and then using a low side transistor to pwm the LEDs to control brightness. Then just a 3.3v LDO to power your micro. If you do want to go low voltage, you could use the same approach with a boost converter or use a shift register which would allow individual control.
  11. Driving a led without resistor probably is not a wise choice. It is worth the time and space.
  12. @antennahead That's really awesome range! Is the design open source at all, it would be cool to see what you did. I assume that you are using a external LNA & PA is this the one from TI as well? Did you have access to a VNA or what was you strategy for getting all of the components matched on a budget?
  13. Yeah you will very likely not be enumerating your virtual com port on com35. Every computer is different based on what other things you have plugged in over time, I have a few launch pads, they show up as com35 or com41, I've also seen com12 on a different pc. The only way to know is to get into device manager and find out. Don't need to use a separate cable.
  14. There's probably an example in code composer too. From a hardware prospective, if you are using LaunchPad, it is already bridged over USB to your pc. Just use device manager to find what com port it is enumerated as and open up the hyper terminal session on that port. The baud rate has to be 9600.
  15. Here's my project directory, C code for msp430: https://github.com/lgbeno/BLDC-Booster/tree/master/firmware/src See serial.c Python code for GUI: https://github.com/lgbeno/BLDC-Booster/tree/master/python See bldc_booster_api.py for serial comms portion See bldc_booster_app.py for the GUI code The bldc_booster.ui file is the design file from QT designer which is the run through a script to automatically create bldc_booster_ui.py
  16. My other suggestion would be using python and QT. I'm a pretty novice software guy but found this to be very easy. I could even point you to some sample code that I have on github if interested.
  17. That's unfortunate but good to know. I noticed the f5510 based LaunchPad that someone did on the forum. Does anyone know of a ftdi based LaunchPad clone that fixes the uart speed and maybe offers native i2c and spi comms? Is it possible to use the ftdi as a msp430 fet debugger in ccs? I can spin pcbs with the best of them but some of the debug software interfaces are a mystery to me. Who would be interested in a board like that?
  18. I apologize in advance if there is already a thread on this but has anyone found a way to bump up the USB to uart bridge baud rate on LaunchPad?
  19. I agree with username for the most part. Only caveat is the comment about a freshly charged lipo being 4.2 volts then to fully discharge, take it down to 2.5 volts, this is where the tps61200 comes in handy. I'd just be careful about the drop across the LDO after it falls out of regulation which it will over the discharge of the battery. So many solutions, hard to choose. I think they all have merit.
  20. Check this out https://www.sparkfun.com/products/10255 And http://www.digikey.com/product-detail/en/SC4503TSKTRT/SC4503TSKCT-ND/1249536 Regs should be $5 if implemented board level
  21. Are you going to spin a board(s) for this? I've used small buck regs from alpha & omega and a boost from semtech. The efficiently is much better than a LDO or a diode and allows you to increase voltage without more batteries. Some also disable themselves when there is a very light load. Depending, sometimes the internal discharge of the battery is the biggest drain on power. For driving actuators like solenoids, hopefully the state that they will be in most of the time is undriven. So if there is a water valve to say water plants, it is on 1% of the time and off the rest. Then I
  22. This is a really cool project, keep up the good work!
  23. I agree, just the scope check out this article http://www2.electronicproducts.com/Frequency_response_A_scope_s_key_unseen_spec-article-farc_rohde_jul2011-html.aspx
  24. Posting a scope trace may help too
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