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I have recently bought a sabertooth 2x25 i am able to control it with a Hobby Transmitter and receiver... I have been wondering if i would be able to control it with my Pi...

Sabertooth 2x25 is a motor driver which supports speed control Here are the full details of the motor driver: http://www.dimensionengineering.com/datasheets/Sabertooth2x25.pdf

There have been many questions like this but i wasn't able to understand anything...

So can anyone please tell me how to do it... I am a beginner so i would be needing everything including the settings of the DIP switches...

Thanks in advance to anybody who tries to help me.

Domme
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DS3a
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  • What is a Sabertooth 2x25? You are expecting those who can help to do the research you should be doing. Please edit your question and explain what it is, provide a link to the documentation, explain what inputs and protocol it uses? – Steve Robillard Aug 25 '16 at 23:05
  • These details belong in your question not the comments, as I said please edit your question and add them there. – Steve Robillard Aug 26 '16 at 23:22

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I've never used one of these but I'll give you a partial answer based on pg. 8 of the document you linked, the "Operating Modes Overview" section, which mentions 4 possibilities for control inputs; I've mashed the last two into one here ("Serial"):

  1. 5V Analog: The Pi's GPIOs are 3.3V digital, so you would need an appropriate DAC device; I think these tend to require a lot of pins unless they include a shift register, otherwise you'd have to add one yourself. The idea behind a shift register is you can send it a series of values (e.g., 8 to make up one byte of information) on one pin and when complete or at specific intervals it will output that value in parallel on an equivalent number of pins (one per bit of information, so again, 8 per byte). Those are the digital inputs of the DAC, which outputs an analog signal on one pin. You might also need a level shifter here (see #3) depending on the input vs. output level of the DAC.

  2. RC: This isn't something I know anything about, but presumably you need a "standard" RC (radio control) transmitter for the Pi, and a receiver for the Sabertooth.

  3. Serial: This is a digital protocol and the Pi has a serial interface, so it is probably the simplest option from a hardware perspective -- all you need is a level shifter. The doc says the Sabertooth uses "TTL level RS-232". TTL level is ambiguous to me with regard to voltage but I think most commonly means 5V; the documentation also refers to using a MAX232 if connected, presumably, to the RS-232 port of a computer, which may use a substantially higher logic level (15+ V), so 5V seems to be the case. The Pi's serial pins are 3.3V, so all you would need in terms of additional hardware is a level shifter.

    The Pi is pretty flexible with regard to baud rate (but you do have to choose one), which you set on the Sabertooth side using the DIP switches.

There's a more in-depth explanation of the 4 modes starting on page 10.

goldilocks
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