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veryalive

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Everything posted by veryalive

  1. veryalive

    Thermistors!

    el cheapo RF 'calorimetric' power measurement - measure the temperature (inferred from the resistance) of the thermistor in close thermal proximity to a resistive RF load. temperature compensation of all sorts of stuff - but I guess you know about that ! : oscillators (frequency and level); stabilizing light output from laser leds or incandescentlamps, etc. if you get some PTCs, that's another story. like those 'resettable fuses''. large PTCs were used for ages in electric power windows as a brute-force method to choke off the current when the motor drove the window full top -or- full bottom.
  2. veryalive

    Thermistors!

    airflow and airspeed indication. eg: to make sure that a fan is cooling a piece of equipment. so, using two thermistors: one isolated from the airflow (reading ambient air temp), the other in the fan's airflow. the two thermistors' resistance difference indicates that the fan properly cools the equipment. i heard of an airspeed indicator that used two thermistors near heated elements. again, one in the static air, the other in the moving air. So here, the moving air cools the heated element, resulting in lower measured resistance than the other thermistor.
  3. veryalive

    SHARP Memory Display Booster Pack

    @@chicken hi and thank you for your test routines for the sharp 96x96 booster pack. I was looking at the cpp file, mainly checking what's available and how to drive that LCD from a memory-limited '2553..... ?????>>> could it be that your display ON / OFF routines need a fix ??? <<<<<< referring to this part of your code in SHARPMemLCDTxt.cpp (comments with <<<... are mine) : void SHARPMemLCDTxt::on() { digitalWrite(m_pinDISP, HIGH); <<<<<<<<<<<<<<<<<< for 'ON' set HIGH....... } void SHARPMemLCDTxt::off() { digitalWrite(m_pinDISP, HIGH); <<<<<<<<<<<<<<<<<< for 'OFF' .... and again, HIGH ...... ?? } I like digging into to other folk's driver code to see how they do it, always want to learn new stuff, so that's when I saw this and thought to ask... cheers.
  4. i've found energia pretty good for most floating point functions. especially on the 2553 as it has enough flash. i haven't done arc-tangent personally, as it would have to calculated from the other transcendentals; but i've used them all in other calculations with success. about your d/a output, it depends on it's particular interface, but again, energia has a nice variety including spi, iic, even bit-banging serial. hope this helps. btw - this assumes you're using a 2553 equipped ti launchpad board.
  5. Hello all, Is it a good idea the increase the number of 'recent topics' displayed on the right side of 43oh's forum page to be more than 5, the current number? Sometimes I get the feeling I'm missing some good stuff after being away for a few days. This is a great forum. Cheers!
  6. thanks guys ! oh, don't mind me --- a low-caffeine start today. i don't know how many hundreds of times i've been here - and missed that 'new content' button. excuses all around, shamefacedly.
  7. veryalive

    Serial com showing nothing

    under the 'tools' tab in energia, verify that the serial monitor is enabled and set for the same async comm speed as your sketch - usually 9600. you know that the serial monitor is enabled because there is a separate window that pops up on your pc screen. hopefully, the problem is as simple as this. good luck ! EDIT --- whoops, i just checked the bottom line of your sketch -- you are using the 2452 processor. you need also to make sure you have the left-most two jumpers at J3 (on the rev1.5 launchpad) 'vertical' --- ie. all 5 jumpers vertical; pointing to the USB connector edge of the board. just so you know, this issue , and others like it, are covered by this forum's on-lin help -or- the energia & launchpad documentation - just to help you get up to speed faster !
  8. veryalive

    MSP430 university project

    @fred : no, not harsh; quite sage in fact. 'give a man a fish, he eats for a day; teach him to fish, he eats for life' @joro energia is very useful for developing code that works well. but, we still don't know what that project should accomplish.
  9. veryalive

    mspgcc right shift question (energia)

    i don't know about the compiler, but here's how 2's complenent arithmetic would work: it means we interpret the byte quantity as a 2's complement number, not as a bit pattern. other machine instructions can interpret the byte 'logically' and fill from the left with zero, the carry bit, etc. so, in 2's compl arith........................ this can be called 'sign extending' where the msb is the + or - sign bit. 80 hex byte = -128 (decimal) right shift -128 (arithmetically, ie divide by 2) = -64 (decimal) -64 (decimal) = C0 hex byte = 1100 0000 binary (!!!!!!! note that the msb is a 'one', this a nice property of right shifting 2's complement numbers !!!!!!!) (it is very standard) now, even in a larger bit machine; such as 16, 32, or even 64 bits; all those extra 'ones' on the left STILL make the same negative number ! so, the decimal number -64 can be 1100 0000 binary byte C0 hex byte 1111 1111 1100 0000 16-bit binary word FFC0 hex word etcetera ciao
  10. veryalive

    Brutal Wire Cutters Needed

    you may want to check out a music shop for piano / guitar string cutters. these type usually, but not always, shear the wire (like scissors) rather than 'pinch' the wire (like diagonal cutters). i've also used tough scissors for cutting thin steel wires (to about 0.010 inch dia). a little loop at the sharp end, formed with needle-nosed pliers, makes that end safer. (edit - yep, i read your link referring to 'piano wire', i was referring to where to buy such 'shearing' cutters)
  11. veryalive

    Arduino TRE

    -------------- a great thread, guys !!!!!!!!!!!
  12. veryalive

    How the heck I should start using CSS?

    Hello to the thread, I too would like to get a handle on CCS. I think some additional, but different, on-line courseware would be helpful. I've given an example, below of courseware that helped me in a related area - keep reading ... I've tried to get up to speed on CCS5.x without much success. I've used other micros, mainly FS. And other tools. I tried the TI course (Stellaris / 430), followed examples on line, etc, but keep running into snags where I often cannot diagnose where I went wrong. So, same result as folks on this thread - back to Energia & async IO breakpoints for debug. But I keep trying as I'd like to have a unified, powerful and cheap (or free) IDE for more than one processor type - in this case TI 430 and ARM (Stellaris, Tiva). I understand these archtectures quite well. I'm also checking the links given on this thread. Here is how I got going quickly with Stellaris using a free version of IAR's ARM toolkit. http://www.state-machine.com/quickstart/index.php I am not related to IAR, or the consulting company doing the videos. in fact I got this link on this forum a few weeks ago. Furthermore, I simply cannot afford to buy a full IAR package for private use. What I like about this course: - it assumes you know something about programming and architectures, so doesn't waste time on basics. - it applies C to the ARM. It's a good refresher as I do not program C on a daily basis, I'm more a system & hardware type. - (best part for me) it is pretty clear on how to use the toolchain. I can rerun the mouse sequences; expand on each step. So, this is just my opinion fwiw. Maybe this thread is of interest to someone at TI, or with more time/knowledge, or with deeper pockets. Cheers.
  13. veryalive

    encoder style for dc motor

    - how about a linear potentiometer, also called a 'slider pot' from an audio system, with the wiper attached to the linear-motion portion of your solution. - then you measure the analog voltage at the slider - this then tells you how much linear motion your actuator has undergone. then control the motor direction in your software. - so, in the diagram below: linear actuator full left would give the highest AtoD value; full right would give the lowest value. MOTOR -----> | Linear actuator = Lead screw | ^ | --- (knob) ------------------------------- | Slider potentiometer | ------------------------------------------ | | | V+ | Gnd | To 430 AtoD cheers.
  14. it was on step 3 = payment. i found the greyed-out indication for 'coupon code', and upon entering the code sa_bts, the price came down to the expected value. thank you for your advice.
  15. hi folks, for the attractive promotion price, how does one get the 24.99$ price in the checkout cart ? i only see 249$ perhaps it is because i reside in europe and i missed some 'fine print' ? thanks for any reply before the offer expires !!
  16. veryalive

    MOSFET failures I can't explain

    i do understand your desire to do the job by yourself = > persistance. - sounds like your wiring is ok, but the mosfets need higher drive voltage than the 430 output provides - if you have bipolar transistors available, you can drive their base via a resistor (1 to 2 K ohm) from the 430, ground the emitters, LEDs to the collectors. they only need about one volt at the base to turn on the collector current. - in this case, a medium power NPN, darlington if you have them. (there any many low cost options, one is BD139) - sticking with bipolar, due to the lower turn-on voltage, think of the uln2003 driver family. multiple drivers in one package for your stated 'compact size' requirement. you may have to invert the logic level in your IO pin-driving software. again, there's lots of similar drivers out there.
  17. veryalive

    MOSFET failures I can't explain

    ----- and just a last thought, just in case : double check that all the mosfets are wired correctly. - specifically, the drain and source connection. if they are swapped, you will get current flowing through the forward biased (zener) diode this means current will always flow, source-to-drain-to-LED, and the LED turns on permanently
  18. veryalive

    8-bit 2-to-1 multiplexer IC

    if you wish to minimize hand wiring & are using veroboad or single sided pcb..... a pair of 'hc541. one on the left, one on the right. BUT the one on the right is upside down; why? so that you can do straight-through wiring on the output lines (so left p18 to right p11. left p17 to right p12. ..etc.. left p11 to right p18) and then select via the output enables on pins 1 and 19. | o | 8 inputs | | 8 outputs | | | | 3-state | | 8 inputs | o |
  19. veryalive

    Hi from Hampshire, UK

    hi there ex-TIer ! if these numbers make sense, consider dropping me a private message: 99xx 99xxx etcetera I really enjoy the 430 platform and have been relearning C programming. Cheers,
  20. veryalive

    Designing a Solar Flare Detector

    Hi, If you want to keep it simple and register an all-important early success with the 430 Launchpad, here is another idea, assuming you have loaded and run Energia. In Energia: File -> Examples -> 3.Analog -> AnalogInOutSerial and load / compile / download it to your Launchpad. Check that tools / processor type (2553) / TxRx jumpers, connections are all set up. The documentation is good. Then you should see the analog values appear on your serial monitor (Energia tools, or your preferred serial monitor). This program reads the 10bit ADC, scales it to 8 bits using the 'MAP' function, then sends it out the serial port. This whole process should take only a few minutes; you can stimulate the ADC channel by touching the associated Launchpad pin with your finger, just to check it. Of course you want to measure a real voltage (nb: max input = 2553 Vcc or about 3.6 volts). You can then customize as you see fit, including tapping into the Async output from the Launchpad and sending it the 15 meters to your R-Pi; rs232 and a lower bit rate would be nice options to accomplish the latter. Then you can soup-up the installation with wireless, additional programming features, etcetera. You can also remove the programmed 2553 chip and place it in its own socket in its own box near the receiver. Cheers,
  21. veryalive

    First etch & surface mount!

    hello @@TheDirty. I agree with the others that your toner method looks great ! Better than my attempts... I second the request for a brief outline on the details that make your boards look so good. I'd like to try again. Since most of us know about the toner method / or / can find info on the web, would you at least share your key ingredients with us : - what toner / printer type you use, plus any printer settings to get the right toner thickness - what type of paper you print on - how you iron the toner onto the blank PCB (temperature / time) - etching chemicals / temperature / time (do you use a zip-lock plastic bag, for instance?) - last but not least - which PCB software package - and do you use 'mirror image' output to printer ? I've heard of some guys turning around toner boards from layout to final product in less than an hour - is this your experience too ? Cheers....
  22. veryalive

    Gameboy using MSP430

    Really cool! Just a small request - can you confirm the connections to the '595 shift registers when you have a moment? Your included schematic is unclear to me in a few areas. I suspect you are using 16 bit transfers with: - shift reg clock connected to latch clock - both driven by 430 (pin?) - Reset tied high and Enable tied low - Serial data into one 595, driven by 430 (pin?) - D7 out from one shift register cascaded to Din of the next one. Did you use CCS for this? Looking forward to hearing from you and trying out your cool project !
  23. veryalive

    Hi there! Plukkie al?

    hoi marc, vanuit plus/min a'veen.... Otto
  24. veryalive

    Hallo from The Netherlands

    Dag Henk, Good that you have joined ! groeten uit vlakbij A'veen. Otto
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