What are some ways to prevent brownouts from occurring? Our team has been experiencing brownout issues with our robot recently and we were wondering what some ways to prevent them were. We are using the RoboRio 1.0
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I would start at your battery and work from there.
Are you checking battery charge state with a battery tester before each match
Are you checking battery internal resistance
How long is your 6/4AWG run from battery to PDP
Are all of your connections and crimps tight and secure.
If all of those are good, then you can look at monitoring the current in your motors and potentially limiting those who trigger your brownouts.
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I also typically suggest making sure you properly ramp power to your motors to prevent high current draws when repeatedly starting them up.
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If you post some driver station logs here we may be able to better isolate what your problem is.
We do check our batteries for voltage and charge levels before use, and our connections are secure. We heard there might be a way to reduce brownouts via code, but we weren’t sure if that was true or not
roboRIO Brownout and Understanding Current Draw — FIRST Robotics Competition documentation You can set a custom voltage for brownouts on the roboRIO 2.0.
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We were thinking about purchasing the Rio 2.0, but as of right now we will have to stick with the 1.0
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Lego, the Roborio 1 versus 2 has no effect on brownout. If you are browning out with the Rio 1, you have issues you need to resolve. You are either running on batteries that are not fully charged, running too long, have wiring issues, or are trying to run too many motors at once.
Newton has a good list of things you can do in code to help.
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You absolutely can limit brownouts in code. Some of the things you can look into are ramp rates, slew rate limiters, current limits, or other things that manage the power draw.
100% valid code options. Also consider that you may have one or more systems geared too fast. Trading torque for speeds will often help in these situations add well.
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Also, don’t stall motors, especially if you have not understood and set current limits appropriately. This is important for multiple reasons.
What are your battery test methods and what are some examples of your test results?
What specific steps are you taking to determine that your connections are secure?
Please list each of the motors you are using, indicating what type it is and what it’s purpose is.
Battery - high quality, “young” (not too many cycles, and “broken in” with 3-5 complete cycles.
Wiring - 4awg, strong connections. No corrosion on connectors, wiring as short as possible.
Software - current limits for all motors (according to theirs needs). This will also prevent damage in case of sensor or mechanical failure.
Ramp rate limits for motors that don’t require tight control.
Indirectly helps - voltage compensation for all motors
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Are you talking about robot brownouts or RoboRio brownouts? The advice here is good for robot brownouts but a rio brownout when the battery is good is possible if you are powering too much from the PWM and DIO. LEDs can draw a lot of power and if you have them on the PWM and don’t hook up additional power leads for the strip you can brown out the rio from the draw on the PWM
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