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R/C channel mixing — Parallax Forums

R/C channel mixing

ArchiverArchiver Posts: 46,084
edited 2003-03-28 15:00 in General Discussion
Classic R/C channel mixing. I need to mix two R/C channels, just as
is used in v-tail mixing.

Here's my problem, I have 3 R/C channels coming into my stamp. I
have a fourth controlling where those channels go. I've figured this
out. However, I am almost out of I/O pins, and I also don't want to
have to buy a R/C channel mixer. If I can mix two of the channels,
it solves alot of my problems.

Thanks in advance, Jim

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-03-20 03:43
    I was hoping to get some help with a servo problem I have.

    I have two R/C channels that I want to mix together. Classically,
    this idea is used airplanes, but I have hopes of using it in a two
    wheeled robot.

    I was hoping someone out ther would have the math behind such a
    problem. Maybe even source code... I have the hardware now I need
    the software.

    Thanks, Jim
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-20 03:43
    I was hoping to get some help with a servo problem I have.

    I have two R/C channels that I want to mix together. Classically,
    this idea is used airplanes, but I have hopes of using it in a two
    wheeled robot.

    I was hoping someone out ther would have the math behind such a
    problem. Maybe even source code... I have the hardware now I need
    the software.

    Thanks, Jim
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-20 14:57
    At 03:43 AM 3/20/03 +0000, you wrote:
    >I was hoping to get some help with a servo problem I have.
    >
    >I have two R/C channels that I want to mix together. Classically,
    >this idea is used airplanes, but I have hopes of using it in a two
    >wheeled robot.
    >
    >I was hoping someone out ther would have the math behind such a
    >problem. Maybe even source code... I have the hardware now I need
    >the software.
    >
    >Thanks, Jim
    >

    Depends on how you want to mix the channels... i.e. A mathematical
    relationship, a lookup table, etc.

    Basically you read in BOTH (or more) channels with the PULSIN command.
    (typical range is 1ms -2ms)

    Perform your DSP (Digital Signal Processing)

    output the result using the PULSOUT command.

    Using a lookup table the relational output can be almost endless

    x - servo CH1
    y - servo CH2
    o - servo combined output

    Example1:

    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    x x x x x x x x x x

    Example2:

    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    x x x x x x x x x x

    Example3:

    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    y o
    x x x x x x x x x x
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-20 15:33
    How sad, your beautiful spacing was removed by the group presenter...
    --- In basicstamps@yahoogroups.com, "Beau Schwabe" <bschwabe@a...>
    wrote:
    > At 03:43 AM 3/20/03 +0000, you wrote:
    > >I was hoping to get some help with a servo problem I have.
    > >
    > >I have two R/C channels that I want to mix together. Classically,
    > >this idea is used airplanes, but I have hopes of using it in a two
    > >wheeled robot.
    > >
    > >I was hoping someone out ther would have the math behind such a
    > >problem. Maybe even source code... I have the hardware now I need
    > >the software.
    > >
    > >Thanks, Jim
    > >
    >
    > Depends on how you want to mix the channels... i.e. A mathematical
    > relationship, a lookup table, etc.
    >
    > Basically you read in BOTH (or more) channels with the PULSIN
    command.
    > (typical range is 1ms -2ms)
    >
    > Perform your DSP (Digital Signal Processing)
    >
    > output the result using the PULSOUT command.
    >
    > Using a lookup table the relational output can be almost endless
    >
    > x - servo CH1
    > y - servo CH2
    > o - servo combined output
    >
    > Example1:
    >
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > x x x x x x x x x x
    >
    > Example2:
    >
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > x x x x x x x x x x
    >
    > Example3:
    >
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > y o
    > x x x x x x x x x x
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-20 15:35
    Works for me....

    Eudora:
    Tools-->Options-->Fonts-->Message-->Fixed-width = Fixedsys
    Use proportional font by default =
    unchecked

    Otherwise just cut-n-paste into NotePad...


    >How sad, your beautiful spacing was removed by the group presenter...
    >--- In basicstamps@yahoogroups.com, "Beau Schwabe" <bschwabe@a...>
    >wrote:
    > > At 03:43 AM 3/20/03 +0000, you wrote:
    > > >I was hoping to get some help with a servo problem I have.
    > > >
    > > >I have two R/C channels that I want to mix together. Classically,
    > > >this idea is used airplanes, but I have hopes of using it in a two
    > > >wheeled robot.
    > > >
    > > >I was hoping someone out ther would have the math behind such a
    > > >problem. Maybe even source code... I have the hardware now I need
    > > >the software.
    > > >
    > > >Thanks, Jim
    > > >
    > >
    > > Depends on how you want to mix the channels... i.e. A mathematical
    > > relationship, a lookup table, etc.
    > >
    > > Basically you read in BOTH (or more) channels with the PULSIN
    >command.
    > > (typical range is 1ms -2ms)
    > >
    > > Perform your DSP (Digital Signal Processing)
    > >
    > > output the result using the PULSOUT command.
    > >
    > > Using a lookup table the relational output can be almost endless
    > >
    > > x - servo CH1
    > > y - servo CH2
    > > o - servo combined output
    > >
    > > Example1:
    > >
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > x x x x x x x x x x
    > >
    > > Example2:
    > >
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > x x x x x x x x x x
    > >
    > > Example3:
    > >
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > y o
    > > x x x x x x x x x x
    >
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2003-03-20 15:55
    --- In basicstamps@yahoogroups.com, "kiltjim" <kiltjim@a...> wrote:
    > I was hoping to get some help with a servo problem I have.
    >
    > I have two R/C channels that I want to mix together. Classically,
    > this idea is used airplanes, but I have hopes of using it in a two
    > wheeled robot.
    >
    > I was hoping someone out ther would have the math behind such a
    > problem. Maybe even source code... I have the hardware now I need
    > the software.
    >
    > Thanks, Jim

    This depends on which end of the RC device you want to add the Mixing.
    I am mixing the Collective and the Throttle for a Helicopter. In
    Moving the collective Joystick the Throttle will track above the
    Collective.
    High 14 'Force +5 volts on Pin 14
    RCTIME 14,1,Collective 'Pot is 5000 ohm
    PotOut = (Collective */ 2500) - 200 'Store it in PotOut For Serial
    Servo = "1" 'Servo 1
    Gosub Display

    High 13 'Force +5 volts on Pin 13
    RCTIME 13,1,Throttle 'Pot is 10000 ohm
    Throttle = (Collective */ 2500) + 50 + (Throttle/2) - 310 'Add to
    Collective
    PotOut = Throttle 'Store it in PotOut For Serial
    Servo = "2" 'Servo 2
    Gosub Display 'Send Throttle Information

    Hope this helps.
    Ken Smith
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-28 15:00
    --- In basicstamps@yahoogroups.com, "kiltjim" <kiltjim@a...> wrote:
    > I was hoping to get some help with a servo problem I have.
    >
    > I have two R/C channels that I want to mix together. Classically,
    > this idea is used airplanes, but I have hopes of using it in a two
    > wheeled robot.
    >
    > I was hoping someone out ther would have the math behind such a
    > problem. Maybe even source code... I have the hardware now I need
    > the software.
    >
    > Thanks, Jim

    Alright, I may have figured it out, but can somebody look at this so
    my robot doesn't get up and kill me?

    'Channel1, Channel2 are outputs
    'Accel and Turn are the readings from Rx. - 1100 (Center)

    Channel1 = Accel - Turn / 2
    Channel2 = Accel + Turn / 2

    Does this make sense? Is it going to go insane and lose control? Is
    this possibly my last post because my robot has killed me?
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