Question for the OpenTX Gurus

Discussion in 'Electrical & Radio' started by SteveT44, Jan 18, 2023.

  1. SteveT44

    SteveT44 Well-Known Member

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    I'm starting to think about controls for my quad bow-mount Atlanta. Does anybody know if an OpenTX transmitter with a 6 position switch could be programed to fire the four cannons in individual mode and all at once? My idea is to use the position switch to select a cannon firing mode. Modes 1 though 4 for individual firing of the cannons (for testing/tweaking). Mode 5 to fire the four cannon channels at once. The fire button would be one of the available on/off switches. If this is possible, could a further refinement be added to the all-fire mode where each cannon would be fired in sequence, with milliseconds between each firing?

    Thanks for any input.
     
  2. GregMcFadden

    GregMcFadden Facilitator RCWC Staff

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    The short answer is yes. The long answer is that you have to diagram out the logic of what you want to do and then we can help find a way to do it. Timers are available they are not terribly precise. I have had better luck with ramped switches as you can much more finely control the on-off time. I currently have all of my cannons set up so that a single fire stick will stay on no longer than a fixed amount of time that I have experimentally determined the cannons required to fire properly I found that helps with gas consumption greatly particularly when letting other people try the ship.

    Depending on the transmitter you have there may or may not be limitations based on the processor so again we have to figure out the algorithm and then we can figure out how to program it
     
  3. SteveT44

    SteveT44 Well-Known Member

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    Thanks for the input Greg. I figured the functionality was there after reviewing your posts on OpenTX. For the Tx, I'm pondering something like the Taranis Q X7 with one of the pots changed out to a six position pot. If I have to go upscale, the Radiomaster T16S looks like a good option.
     
  4. GregMcFadden

    GregMcFadden Facilitator RCWC Staff

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    Basically any of the new ones ought to have plenty of memory and functionality in the processor. I have at least one transmitter still running older versions of open TX on an 8-bit processor and they are extremely limited relative to any of the new stuff
     
  5. GregMcFadden

    GregMcFadden Facilitator RCWC Staff

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    What I'd recommend you do is look at how logical switches work and how they can be combined with slow options for the mixers. You can set a logical switch such that it trips at a specified value from one of the mix channels and use the slow ramp rate to control how long it takes to get there and by doing so have extremely fine control over time of a transient switch.


    For the rest of your logic it's more about figuring out the right combination of logical switches that activate the right set of channels to do what you want to do.

    Do not be afraid of using some of the mix channels that you don't have output ports for on the receiver or don't connect to as dummy calculation channels whose values are then used to drive switches which then drive other mix channels you output to your receiver

    All of this can be done using the companion software package on the computer without ever touching the transmitter and you can tell if it'll work on a transmitter before you ever buy it
     
    Last edited: Jan 19, 2023
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