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calin

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  1. Like
    calin got a reaction from Gyula84 in Spikes on PWM output   
    I am doing a fan controller using PWM. All nice, things work good etc. but I noticed something really odd on PWM output the transition has an super nasty ringing happening which is almost 5V peak to peak. It overshoots really nasty in both directions/transitions. I used the sample code from TI with just the launchpad nothing else connected except the scope. Tried different pins instead of 1.6 also .. same.
     
    Normally the output should swing smoother - a ring from 3.6V to 5V is huge. Did you guys ever noticed something like that ? pretty nasty.
     
    BTW ... with a simple 1uF cap to ground i reduced the spike/ring to 4.12 and it settles very fast but still I find this annoying. Especially when you switch transistors the spike does not very nice things down the line.
     
    #include <msp430g2231.h> void main(void) { WDTCTL = WDTPW + WDTHOLD; // Stop WDT P1DIR |= BIT6; // P1.6 P1SEL |= BIT6; // P1.6 TA1/2 options CCR0 = 512-1; // PWM Period CCTL1 = OUTMOD_7; // CCR1 reset/set CCR1 = 384; // CCR1 PWM duty cycle TACTL = TASSEL_2 + MC_1; // SMCLK, up mode _BIS_SR(CPUOFF); // Enter LPM0 }
  2. Like
    calin reacted to cde in Has TI 's samples policy changed ?   
    You have to put "Independent Designer", unless you work for a big company or something. The 5 items, y number per items depending on which category they decided you are is still the same for two three years now (for example, 2 limit of any individual microcontroller, 5 for some individual regulators, 1 of any regulator module, etc if you are an independent designer/regular student). It used to be 8 quantity of any 8 parts, but that was years ago.
  3. Like
    calin got a reaction from Rickta59 in Linux Serial Communication working w/modified cdc-acm module   
    Confirmed working with kernel 3.2.0-27-generic x86_64 (Ubuntu 12.04 - 64 bit) .
  4. Like
    calin got a reaction from Rickta59 in Linux Serial Communication working w/modified cdc-acm module   
    Confirmed working with kernel 3.2.0-27-generic x86_64 (Ubuntu 12.04 - 64 bit) .
  5. Like
    calin reacted to Rickta59 in Linux Serial Communication working w/modified cdc-acm module   
    So I finally tried out the replacement cdc_acm module from the e2e forums. I'm using the file 7028.msp430_patch.zip mentioned in this post http://e2e.ti.com/support/low_power_rf/f/156/p/53610/697952.aspx#697952. I'm using Ubuntu 11.04 with a 2.6.38 kernel. Installing this patch solved my problems with /dev/ttyACM0 and linux.
     
    I tried the unmodified Energia ASCII Table example. The code in that sample doesn't wait before sending data, however with this patched module it just works. With the old cdc-acm my whole UI would freeze for multiple 10s of seconds.
     
    There are some things that are different from an Arduino. The main one being the launchpad doesn't reset the msp430g2553 chip when it receives a DTR line signal down the /dev/ttyACM0. What does that mean? Opening and closing the serial console doesn't restart the msp430. When you open the window you must press the reset button on the launchpad to have it restart like an Arduino would. However, with this patch, the UI doesn't lock up any more or stall when you first run it. You also don't have to be worried about printing data when the serial console isn't open.
     
    Two other people have also tried this patch with similar good results. One system was Ubuntu 10.04/2.6.something kernel and arch linux with a 3.something kernel.
     
    I think this goes a long way to addressing stability for the linux version of Energia. Yay Gerald Stanje the kernel hacker author. +1
     
    -rick
  6. Like
    calin reacted to jsolarski-backup in Linux & Launchpad - backchannel UART broken on latest kernel   
    If you have dkms installed, there is a patch floating around on this site that fixes the serial issue and may fix your hosed driver without recompiling your entire kernel
  7. Like
    calin got a reaction from bluehash in Linux & Launchpad - backchannel UART broken on latest kernel   
    I think I may have answered my own question ... Clearly something is hosed with the cdc_acm module. Just after posting I realized that I still have around few older kernels on my machine. So a quick reboot into
     

    Linux obellix 3.2.0-23-generic #36-Ubuntu SMP Tue Apr 10 20:39:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
     
    and I managed to connect successfully, then plug unplug killed the serial again.
  8. Like
    calin reacted to RobG in Universal Panel Meter   
    You can use higher resistance divider, just increase sampling time.
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