I want to build an LED brake light for a bicycle. I don't want any mechanical switches connected to the pedals. I have, for the moment, ruled out measuring the wheel speed to see when it is increasing or decreasing. I have also thought about using GPS to measure the speed, but am afraid there might be too much lag time. For now, I want to use inertia to control the LEDs.
The budget is not unlimited, but I don't have to have the lowest cost possible. Rather, I want the best operation possible.
The basic idea is that deceleration causes the LEDs to light, and a lack of deceleration causes the LEDs to go out. I don't want bumps in the road to cause flickering. I don't want riding up a hill to cause the LEDs to light, but I do want the LEDs to light during deceleration while going downhill and/or leaning (i.e., I want the circuit immune to the inclination attitude of the bicycle, both front to back and side to side.) It may be that the circuit needs to differentiate between slowing down while coasting and actual breaking, but maybe not.
I know that there are such things as electronic accelerometers, but I have never used one. Perhaps that is the best way to sense deceleration and cancel out the effect of inclination attitude? I have some experience with micro-controllers and will use one if needed.
The unit is to be battery powered, but can be whatever voltage works best. To conserve battery life, it would be nice if the circuit went into a power-off mode during periods of inactivity (no motion.)
Your input is solicited. Thanks.
The budget is not unlimited, but I don't have to have the lowest cost possible. Rather, I want the best operation possible.
The basic idea is that deceleration causes the LEDs to light, and a lack of deceleration causes the LEDs to go out. I don't want bumps in the road to cause flickering. I don't want riding up a hill to cause the LEDs to light, but I do want the LEDs to light during deceleration while going downhill and/or leaning (i.e., I want the circuit immune to the inclination attitude of the bicycle, both front to back and side to side.) It may be that the circuit needs to differentiate between slowing down while coasting and actual breaking, but maybe not.
I know that there are such things as electronic accelerometers, but I have never used one. Perhaps that is the best way to sense deceleration and cancel out the effect of inclination attitude? I have some experience with micro-controllers and will use one if needed.
The unit is to be battery powered, but can be whatever voltage works best. To conserve battery life, it would be nice if the circuit went into a power-off mode during periods of inactivity (no motion.)
Your input is solicited. Thanks.
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