Page 6 of 13 FirstFirst ... 45678 ... LastLast
Results 51 to 60 of 130

Thread: GCode Angel project

  1. #51
    Insider new ion?'s Avatar
    Join Date
    Feb 2013
    Location
    Victoria, BC
    Posts
    1,296
    Also using a Schottky for that?

  2. #52
    Shots fired!!



    A couple small modifications and it shoots really well now. I was giggling like a little girl but I ran out of air before i could take another video.

    Quote Originally Posted by new ion? View Post
    Reverse current protection?

    Is this the same as reverse voltage from the solenoid? Just trying to understand what you're getting at.

    edit - Your schematic in the first page seems to have a Schottky already placed to handle this.
    Quote Originally Posted by new ion? View Post
    Also using a Schottky for that?
    The schottky by the noid connection header is to act as a flyback diode to dissipate the voltage surge generated when the coil is de-energized and the magnetic field collapses.

    The barrier dioide by the battery connection is to save the system if the battery is hooked up incorrectly. The down side is the voltage drop (.5v) this brings into play. Luckly we have a little bit of room to play with. Polarity protection can also been done with a transistor with minimual drop Read here for more detail.
    Last edited by Dirty Engineer; 04-29-2015 at 12:08 AM.

  3. #53
    Insider new ion?'s Avatar
    Join Date
    Feb 2013
    Location
    Victoria, BC
    Posts
    1,296
    Yea, knew about the Schottky acting as a flyback, though for those that didn't know, the links were super helpful.

    (I actually stupidly forgot about flyback voltage on a board I designed... it had other issues thank goodness)

    I was asking more about using a Schottky diode for reverse voltage protection because Schottkys have lower forward voltage drops than a regular p-n junction diode. I guess I just worded that sentence poorly.

    All of those reverse battery current circuits include a small voltage drop across the diode, no? IIRC the body diode on FETs is a Schottky simply due to construction, meaning ~0.4V drop.

    Either way, all of those circuits should probably also include a FET controlled by both the button as well as the microcontroller... positive isolation from the battery is good, no?

  4. #54
    Quote Originally Posted by new ion? View Post
    All of those reverse battery current circuits include a small voltage drop across the diode, no? IIRC the body diode on FETs is a Schottky simply due to construction, meaning ~0.4V drop.
    You are correct that the FETs do have an integrated diode but you must remember that this only comes into play when the battery is connected. Once connected the FET turns on and the voltage drop is minuscule.

    Quote Originally Posted by new ion? View Post
    Either way, all of those circuits should probably also include a FET controlled by both the button as well as the microcontroller... positive isolation from the battery is good, no?
    Correct, the easiest and cleanest way to do this is with a voltage regulator with an enable input.

  5. #55
    Junior Member
    Join Date
    Mar 2015
    Posts
    18
    Quote Originally Posted by jptheripper View Post
    added another diode for reverse current protection, and v2 going to fab tomorrow. First shooting test tonight!
    Speaking of diodes, did you consider a diode + zener flyback protection?

    See http://jumperone.com/2011/10/using-relays/

  6. #56
    Quote Originally Posted by Squirrel View Post
    Speaking of diodes, did you consider a diode + zener flyback protection?

    See http://jumperone.com/2011/10/using-relays/
    I would be very interested to see the different response times when using paintball solenoid valves.

  7. #57
    Junior Member
    Join Date
    Mar 2015
    Posts
    18
    Quote Originally Posted by Dirty Engineer View Post
    Correct, the easiest and cleanest way to do this is with a voltage regulator with an enable input.
    I use this one for my board:

    Power.JPG

    SAM_SW goes to an input of the Atmel SAMD21, DCDC_PWR_EN is the enable input of the switching regulator (2ľA quiescient current if disabled), SAM_PWR_EN is an output from the controller that is switched on after bootup.

    Keep in mind to add a 100K resistor between SAM_SW if port pins of your processor have input clamp diodes.

    Additional benefit: measure 9V battery voltage if (and only if) key is pressed if SAM_SW is connected to an analog input

  8. #58
    Junior Member
    Join Date
    Mar 2015
    Posts
    18
    Quote Originally Posted by Dirty Engineer View Post
    I would be very interested to see the different response times when using paintball solenoid valves.
    PE uses this for Etek boards, so I do.

  9. #59
    Significant code updates

    1. Gametimer done. 60 min max, 0-10mins, then 15, 20, etc.. 60+ 0-9 seconds
    2. Oled updates for power conservation and gametimer display
    3. Led adjustments for power on bootup (drawing around 41ma on boot now)
    4. Changes in battery polling (power usage also)
    5. minor bug fixes
    6. Reactive trigger code complete for semi (true reactive) and ramp (reactive only after x shots of semi, then back to semi after timeout)
    7. Registry entry for eye mode (breakbeam, reflective, off ) - remembers setting so if you set for a blind gun you dont have to turn off every time, can still toggle eyes mid game with trigger if you have them enabled in registry
    8. Shot counter/Shot missed (due to eye issue) counter
    9. total shot counter in registry
    10. Menu adjustments
    11. more i cant think of

  10. #60
    Insider
    Join Date
    Feb 2013
    Location
    Mount Vernon, WA
    Posts
    52
    Super cool work. I would love to see a "universal" version (Emag)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •