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    large arrays and enhansed core 16F1xxx

    Using the 18Fxxxx arrays can be larger than 256 locations. This is because of linear memory.
    The little 16F parts do not use memory well and cannot have large arrays.
    The 16F1xxx "enhanced core"...
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    Re: RS485 line driver in SSOP-8

    I could not find a SSOP that is 3.3 & 5.0V. They come in 3.3 OR 5.0.
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    linear data memory & large data arrays

    I started a project using the 18F26K20 so I could use large arrays but I need a smaller part so am thinking of using the 16F1825 which has linear data memory.
    I need a 484 byte array.
    The data...
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    Re: AC Motor speed control

    I would not run the motor at 5 on/5 off. That will cause the motor to vibrate at 6 hz. Keep the on/off as fast as possible.

    I know of a commercial product that switches at 1/2 cycles. At 50%...
  5. Re: Drive an LED direct from a PIC IO pin (ie no current limiting resistor)

    Driving LEDs without a resistor:
    LEDs are current to light devices not voltage to light. The forward voltage is for reference only.
    I just looked through 10 data sheets for parts we are using. ...
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    Re: Speeding up the PIC SPI

    I think the 18f4585 can run at 40mhz with the PLL on. The SPI should run at 10mhz.
  7. Re: how to read sine wave response from sensor

    http://www.tande.com.tw/ins-img-anemometer/specs-nrg40h.pdf
    I think it needs a 250 ohm resistor to +5 volts. Its output is square wave.
    It looks like the MPH=about 1.7 x frequency.
    If you counted...
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    Re: Bring it to Market, But HOW ?

    Marketing MARKETING marketing…..I can’t say this enough. Look at what they sale on night time TV.
    A really good product and no marketing = 0
    I have built too many prototypes just to see the...
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    Re: Working PIC with Frequencies

    If clock=20mhz and you counter is running at 5mhz then the counter is counting in 0.2uS steps. If the counter=1 then 0.2uS. If the counter=10 then 2uS. 100=20uS 1/20uS=(50khz)

    If the frequency...
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    Re: 12bit Power Supply

    Very clever. What LCD did you use?
    I have on my bench a Agilent N6705A that has many of he same functions. It only costs the price of a small car.
  11. Re: DS1803 digital pot - can't get it working!

    The 2nd word, "command" should be 101010xx where xx=which pot.
    Why"IF B0 = 255 THEN LOOP"?
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    Re: PCB manufacturers

    4PCB.COM

    0.008 two layer
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    Video to PIC

    I am looking for a way to see a small number of pixels using a PIC. I saw a project where Horizontal and Vertical sync form a camera interrupts the PIC. Then count over in time to the pixel in...
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    Re: Making PCB, best software

    The little version of Eagle is free. Try with no money down.
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    Re: PLEASE HELP...read write issues

    If you think the LCD is the problem....Have you tried "hello world" to the LCD? Try something very simple first.
  16. Marketing is most important.

    Marketing is most important.
    1) The best product for a very low price and no one knows about it.
    2) A piece of junk all over TV and the internet, great made- up reviews, 1-800-SEND-MONEY, with a...
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    Re: High voltage transistor

    That does not tell me much.

    High voltage transistors (NPN) are slow!! An 800 Volt transistor is faster than a 1000V part. The 1500 volt parts I used are dog slow.

    My experiance is from...
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    Re: High voltage transistor

    MOSFET=
    STW3N150, IXTV03N400S, IXTH6N150, STFV4N150,
    There are a bunch of numbers from IXYS and STMicroelectronics.

    Many of the transistors are not in production now. You can find old stock.
    ...
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    Re: sinusoidal PWM

    Do you know Excel?
    Here is 5 minutes work. Left side is 0 to 255. Right side is 0 to +127 to 0 to -127 to 0.
    Graph right side!
    0 0.0 0.0000 0.0000 0
    1 1.4 0.0246 0.0246 3
    2 2.8 0.0493 0.0493 6...
  20. Re: Low frequency audio level detector using PIC ADC?

    127,127,126,127,127,126, etc) APPROX. = 126.67
    If you have a voltage =126.66 in 8 bit mode you will likely get 127 and 126 readings.

    If I use 1% resistors then the error from resistors could be...
  21. Re: Low frequency audio level detector using PIC ADC?

    Audio has a large dynamic range. I wanted to get as much range as possible. I needed to “zero” at 512 (10 bit). Resistors at 1% and even 0.1% did not always get me to zero. I also tried...
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    Re: Generating square-wave of 200kHz

    Why interrupts?
    Why not use PWM?
    Why not use CCP1, CCP2?
    One of the PWM examples shows changing the dutycycle by 25nS. This gives me the idea you could change the frequency in 25nS steps.
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    Re: sinusoidal PWM

    1) You could use the 32 location array you pointed at in question 3. I used M.S. EXCEL.
    3) Get the data sheet for the PIC in PDF format and search for _OSC_HSPLL_1H or some piece of that. In the...
  24. Re: Low frequency audio level detector using PIC ADC?

    If you search for VU meter you will find examples of what you are working on.
    With out a PIC the two attached pictures show an analog way of getting average and peak readings.
    The rectifier is: ...
  25. Re: Low frequency audio level detector using PIC ADC?

    Back at post #42 there is a picture of a square wave, (not so square wave) and a comment about how bad it looks. The wave looks like this because it has just passed through a capacitor. (A high...
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