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NatureTM

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NatureTM last won the day on July 11 2013

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About NatureTM

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  • Birthday 10/25/1982

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    WI
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    Lots of stuff.
  1. The one I used is not cheap, but about 3x less than the one you linked to: http://www.digikey.com/product-detail/en/HMC1021Z-RC/342-1061-ND/1663120
  2. I did a lot of work on battery-operated parking sensors for a startup recently. We used magnetic sensors that are sensitive enough to detect distortions in the earth's magnetic field. The iron an an automobile distorts the field and either increases or decreases the detected field which is read from the sensor by ADC. They're quite low power to begin with, plus you can switch them on with a transistor for low duty-cycle sampling, leading to very long operation from battery. http://www.magneticsensors.com/vehicle-detection-solutions.php In our project we used the HMC1021 in our case. I don't think I'm able to share code, but they were very simple to operate, and the datasheet has nice example circuits.
  3. NatureTM

    Numitron Clock

    I just wanted to share a clock I made as a Christmas present for my dad. I just finished it, but luckily he's patient. I have a video, schematic, code, and more details on my blog, www.naturetm.com.
  4. Hi everyone, it's been awhile. I just wanted to share something interesting lasershark mentioned on my blog awhile ago. It's basically a way to make music with one line of code. It took about 15 minutes to implement on a g2553 and only requires a launchpad and a speaker. I found it pretty entertaining. Just connect one terminal of the speaker to Port 1.2 and the other to ground, or drive it with a transistor. Original project @ http://canonical.org/~kragen/bytebeat/ #include "msp430g2553.h" #define MCLK 8000000 #define OUTPUT_SAMPLES_PER_SECOND 8000 #define PIN_SPEAKER BIT2 unsigned long t = 0; unsigned char sample; void main(void) { WDTCTL = WDTPW + WDTHOLD; DCOCTL = CALDCO_8MHZ; BCSCTL1 = CALBC1_8MHZ; P1SEL |= PIN_SPEAKER; P1DIR |= PIN_SPEAKER; TA0CTL = TASSEL_2 | MC_1; TA0CCR0 = (0x0001 << 8) - 1; TA0CCTL1 |= OUTMOD_7; TA1CTL = TASSEL_2 | MC_1; TA1CCR0 = MCLK / OUTPUT_SAMPLES_PER_SECOND - 1; TA1CCTL0 |= CCIE; _enable_interrupts(); while(1){ sample = ((t<<1)^((t<<1)+(t>>7)&t>>12))|t>>(4-(1^7&(t>>19)))|t>>7; // sample = t*(((t>>12)|(t>>8))&(63&(t>>4))); // sample = (t*(t>>5|t>>8))>>(t>>16); // sample = t*(((t>>9)|(t>>13))&(25&(t>>6))); // sample = t*(((t>>11)&(t>>8))&(123&(t>>3))); // sample = (t*5&t>>7)|(t*3&t>>10); // sample = (t&t%255)-(t*3&t>>13&t>>6); // sample = t>>4|t&((t>>5)/(t>>7-(t>>15)&-t>>7-(t>>15))); // sample = (t*9&t>>4|t*5&t>>7|t*3&t/1024)-1; // sample = ((t*(t>>12)&(201*t/100)&(199*t/100))&(t*(t>>14)&(t*301/100)&(t*399/100)))+((t*(t>>16)&(t*202/100)&(t*198/100))-(t*(t>>17)&(t*302/100)&(t*298/100))); // sample = t*(t^t+(t>>15|1)^(t-1280^t)>>10); // sample = t&t>>8; //44 khz // sample = ((t/2*(15&(0x234568a0>>(t>>8&28))))|t/2>>(t>>11)^t>>12)+(t/16&t&24); // sample = ((t*("36364689"[t>>13&7]&15))/12&128)+(((((t>>12)^(t>>12)-2)%11*t)/4|t>>13)&127); t++; LPM0; } } #pragma vector = TIMER1_A0_VECTOR __interrupt void T1A0_ISR(void) { TA0CCR1 = sample; LPM0_EXIT; } Switch which "sample =" line is uncommented to change the "song." The songs are from http://pelulamu.net/countercomplex/music_formula_collection.txt and there are more in that file.
  5. Yeah, I haven't been doing a lot of hobby stuff recently, and when I did, it was usually fpga. I'm thinking I'll be on more this winter.
  6. Here's something I had going awhile back. I didn't finish it do to some bug/got bored/meh. The circuits are the same as what gordon posted. My intent was to send the distance data to another uC through serial. Here's the code I had going and a pic. Hopefully I left things in a working state. PS Don't look at the code if you wanted to figure it out yourself. I think I was pretty close to finished. #include "msp430g2231.h" //#include #define PIN_RECEIVER BIT4 #define PIN_TRANSMITTER BIT2 // SPI pins for reference, do not affect code: #define PIN_SCLK BIT5 #define PIN_SDO BIT6 #define ADC_MAX 1023 #define MCLK_FREQUENCY 16000000 #define TRANSMITTER_FREQ 24000 #define WDT_DIVIDER 64 #define SPEED_OF_SOUND_IN_PER_SEC 13071.3f #define MINIMUM_DISTANCE_IN 8 #define MAXIMUM_DISTANCE_IN 600 #define PINGS_AVERAGED 1 #define sendPing() TACTL |= MC_1 #define stopTransducer() TACTL &= ~MC_1 const unsigned long WDT_FREQUENCY = MCLK_FREQUENCY / WDT_DIVIDER; const float WDT_TICKS_PER_IN = (MCLK_FREQUENCY / WDT_DIVIDER) / SPEED_OF_SOUND_IN_PER_SEC; char iTransducerCycle = 0; char nTransducerCycles = 7; volatile unsigned long wdtCounter = 0; volatile unsigned long tPing; void setup(){ const unsigned int SONAR_PERIOD = MCLK_FREQUENCY / TRANSMITTER_FREQ; DCOCTL = CALDCO_16MHZ; BCSCTL1 = CALBC1_16MHZ; WDTCTL = WDTPW + WDTTMSEL + WDTIS1 + WDTIS0; IE1 |= WDTIE; // setup pwm for ultrasound gen TACCTL1 |= OUTMOD_7; TACCR0 = SONAR_PERIOD; TACCR1 = SONAR_PERIOD / 2; TACCTL0 |= CCIE; TACTL |= TASSEL_2; P1DIR |= PIN_TRANSMITTER; P1SEL |= PIN_TRANSMITTER; // setup adc to capture echo ADC10CTL1 |= ADC10SSEL_3 + INCH_4; ADC10CTL0 |= ADC10ON + ENC + ADC10SHT_0; // setup USI USICTL0 |= USIPE6 + USIPE5 + USIMST + USIOE; // Port, SPI master // USICTL1 |= USIIE; // Counter interrupt, flag remains set USICKCTL = USIDIV_7 + USISSEL_2; // SMCLK/128 for 125000 baud @ SMCLK 16MHz USICTL0 &= ~USISWRST; // USI released for operation USICNT |= USI16B; // shift out 16-bits _BIS_SR(GIE); } //void delayMillis(unsigned long milliseconds){ // // todo: add rollover handling // unsigned long wakeTime = wdtCounter + (milliseconds * WDT_FREQUENCY / 1000); // while(wdtCounter < wakeTime); //} unsigned long locatePeak(unsigned long startTime, unsigned long endTime){ unsigned long peakTime = 0; unsigned long conversionTime; unsigned int peakValue = 0; unsigned int analogValue; while(wdtCounter < startTime); while(wdtCounter < endTime){ ADC10CTL0 |= ADC10SC; conversionTime = wdtCounter; while(ADC10CTL1 & ADC10BUSY); analogValue = ADC10MEM; if(analogValue > peakValue){ peakValue = analogValue; peakTime = conversionTime; } } return peakTime; } float wdtTicksToInches(unsigned int ticks){ return ((ticks / WDT_TICKS_PER_IN) / 2);// + 0.5; } float inchesToWdtTicks(float inches){ return(inches * WDT_TICKS_PER_IN * 2); } float getDistance(unsigned long minimumWdtTicks, unsigned long maximumWdtTicks){ unsigned long tStrongestEcho; sendPing(); while(TACTL & MC_1); // wait for ping transmit completion tStrongestEcho = locatePeak(minimumWdtTicks + tPing, maximumWdtTicks + tPing); return wdtTicksToInches(tStrongestEcho - tPing); } void TX_Data(unsigned int data){ while(USICNT & 0x1F); // wait for previous TX completion USISR = data; USICNT += 16; } void main(){ char iPing; float averageDistance; unsigned int distance; unsigned int minimumWdtTicks; unsigned int maximumWdtTicks; setup(); minimumWdtTicks = inchesToWdtTicks(MINIMUM_DISTANCE_IN); maximumWdtTicks = inchesToWdtTicks(MAXIMUM_DISTANCE_IN); while(1){ if(PINGS_AVERAGED > 1){ averageDistance = 0; for(iPing = 0; iPing < PINGS_AVERAGED; iPing++) averageDistance += (getDistance(minimumWdtTicks, maximumWdtTicks) / PINGS_AVERAGED); distance = averageDistance + 0.5; } else distance = getDistance(minimumWdtTicks, maximumWdtTicks) + 0.5; TX_Data(distance); } } #pragma vector=TIMERA0_VECTOR __interrupt void Timer_A0 (void){ if(iTransducerCycle < nTransducerCycles) iTransducerCycle++; else{ tPing = wdtCounter; stopTransducer(); iTransducerCycle = 0; } } #pragma vector=WDT_VECTOR __interrupt void watchdog_timer(void){ wdtCounter++; }
  7. NatureTM

    TA0.0

    If you look at the "application information" section of that datasheet, it shows what pins are connected to the timer A hardware. You're looking for TA0.1 (Timer A0, CCR1) under the "function" column. You'll see your only options are P1.2 and P1.6. I usually try to build my design around the hardware, but if that's not an option, you could use interrupts and software to make it work. It would be a matter of toggling the pin appropriately during the CCR0 and CCR1 ISR's. To use P1.6, change the instances of BIT2 to BIT6 like you did, but use P1.6, not P1.5. If you really want to use P1.5, this might be a good chance to (re)familiarize yourself with interrupts.
  8. My synth used Timer A in capture mode if you don't mind having to wade through all the unrelated stuff. viewtopic.php?f=9&t=513&start=10#p5281 I think this is the important part: P1SEL |= PIN_MIDI_DATA; // Timer A capture input TACCTL1 |= CCIE + CAP + CM_3; // enable capture and interrupt on rising and falling edge ... // CCR1 capture interrupt. Triggers on both edges, adds fresh midi data #pragma vector=TIMERA1_VECTOR __interrupt void CCR1_interrupt(void){ TAR = 0; TACCTL0 &= ~CCIFG; unsigned int tEdge = TACCR1; midiRXBitState = PIN_MIDI_DATA & P1IN; TAIV = 0; addBits(tEdge, !midiRXBitState); }
  9. NatureTM

    Off-Presso?

    My friend works at a pretty nice coffee shop and he told me the reason you don't store coffee in the fridge is because it acts like baking soda, taking on all the flavors/smells of the other stuff in the fridge. Not entirely related to what you're saying, but maybe somewhat relevant.
  10. I'm a pretty avid gamer. Games I've been playing recently: Battlefield Bad Company 2 multiplayer CoD Black Ops multiplayer Supreme Commander Frozen Synapse I play one or more of those almost daily, and I play a whole mess of other games ranging from Angry Birds to Silent Hunter a little less frequently. I refuse to play WoW though, sounds like digital crack. I've got fairly decent hardware: Sandy Bridge i7 2600K overclocked 8G RAM SSD OS disk 2x physical HDD's in RAID0 for speed 2x GTX 260's in SLI 24" 1920x1200 monitor I claim 0 dependents on my taxes during the year, and often use the resultant tax refund to upgrade my box. I think I'll have to upgrade the GPU's next spring, but they still run most games at max settings/res. It's an expensive hobby for a college student.
  11. That amazing synth and now this TV ouput game? Quit outdoing all my projects! Kidding! Exciting stuff. I'm looking forward to learning from your posts. You're awesome.
  12. So many good projects this month, I'm really impressed. I'm going to have to think it over awhile before I vote. You guys are awesome!
  13. That's incredible, and I will be studying your code, thanks!
  14. I think xpg's got it, and you also might want to call that __low_level_init() function as the first line of main().
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