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David38

Member Since: September 28, 2012

Country: United States

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http://david.carybros.com/

  • Often the terminal voltage of a so-called “12 V battery” will get dragged down to 6 V (or lower!) when it’s connected to a motor trying to move a heavy load. Test: If you wire both motors directly to your “24 V” power supply (replacing the L298 with some wires), do you see the same 12 V? If so, the L298 is working as designed; that is normal. (Although you may want to consider getting a higher-current power supply).

  • I had a similar problem with something that worked fine when powered from my benchtop power supply, but sounded weird when powered from a wall wart. Apparently my wall wart was too wimpy to keep up with sudden changes in current. I fixed it by adding a big capacitor – 1000 uF – across V_RAW and GND.

  • Thank you, Joe P. – I was also getting weird values for ABS_POS. After I fixed dSPIN_Param() by sprinkling “unsigned long” casts as you recommended, ABS_POS now works great – thank you!

  • The schematic shows a 200KOhm variable resistor “R4” connected to “ADC” (pin 5). I looked all over the board I have in my hands, and I can’t find R4 anywhere. Am I going blind?

  • Driving the steppers of a 3 axis CNC machine with L6470 chips sounds great. Would you mind writing up an outline of a basic tutorial somewhere with everything you wish you had known at the start – perhaps using “???” question marks to fill in details you still don’t know but wish you did? Would the RepRap wiki be a good place to post this basic L6470 tutorial ?

  • Reading a little between the lines, I eventually found this translation for that esoteric language:

    Connect the L6470 “SW pin” on the board to the Arduino pin 8. Optionally, connect the L6470 “SW pin” on the board to some sort of “limit switch” that grounds the pin when it hits the limit, and lets the pin float high when operating normally.

    The L6470 “SW pin” is an input pin. If the Arduino or the “limit switch” or any other OUTPUT drives the L6470 “SW pin” low, by default the L6470 responds by immediately stopping the motor.

  • effgee and sgm2o2, I feel your pain. I went around in circles for far too long before I figured out:

    • Download the .zip
    • Extract the files – I get a folder named “dsPin_example” with 4 “.ino” files in it.
    • KEY STEP: rename the folder to “dSPIN.example” (without the quotes). (On my system, it doesn’t even compile unless I get the capitalization exactly right)

    • double-click on the “dSPIN_example.ino” file (resist the temptation to click on the “dSPIN_main.ino” file)

    • The Arduino IDE should start right up and show all 4 files in tabs at the top. (You have already downloaded and installed the Arduino IDE from http://arduino.cc/en/Main/Software , right?)
    • You hit the “dSPIN_main.ino” and let the Arduino create new folders, didn’t you? Close the Arduino IDE, put all 4 files back into the “dSPIN.example” folder, and delete the empty folders that the IDE created. Double-click on the “dSPIN_example.ino” file.
    • In the Arduino IDE, hit the right-arrow “compile and upload” button.

    I suspect that might be all you need to do if you have an Arduino Uno. But if you have an Arduino Mega2560 like I do,

    • Change the pin map in “dSPIN_example.ino” as recommended in http://forum.arduino.cc/index.php/topic,27395.0.html so SLAVE_SELECT_PIN , MOSI , MISO , and SCK are defined as the correct pins for the Arduino Mega2560
    • Actually wire up the Arduino and the motor as per the pins defined in “dSPIN_example.ino”.
    • Hit the right-arrow “compile and upload” button.

    Is there some way to fix that library so it automagically uses one set of pins for the Arduino Uno and a different, but still correct, set of pins for the Arduino Mega2560?

  • What is he difference (if any) between this LilyTwinkle and the LilyTiny ?

  • Is this different in any way from the LilyTwinkle?

No public wish lists :(