Anyone know of a source for a cheap separate ultrasonic transmitter and receiver. I want the transmitter to have a wide field and work to approx 30 feet, 40 would be better.
I have found a few schematics on line but thought if there was one out there already that fit the bill it would be easier. Thanks in advance.
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Since it seems no one knows of a ready made one, any help in design would be great. I want this to begin working on a simplified localization system for a bot in a 15x15 room. I will use trilateration with some estimation as I would like to only have two corner located transmitters.
Theory of operation:
- Bot sends RF signal to first corner device.
- Bot sends IR signal and starts timer
- Remote receives IR signal and sends ultrasonic pulse (s)
- Bot measures arrival time(s)
- Bot repeats for second remote.
- Bot calculates position via trilateration. Should be accurate down to ~ 1 inch.
Will require some floating point math but toughest thing is arccos calculation. Accuracy of this will drive how accurate the position is. Some fudge will be necessary as I’m hoping not to deal with the Z axis (height). This keeps equations simpler. Since I’m placing the remotes in corners I can eliminate the opposite side of the circle’s solution.
I want to go through a set up process where the Bot is placed in various positions, i.e. under remote 1 and under remote 2 to determine distance between remotes. Otherwise I will need to measure this and build into calculations manually. I would rather have it set up for any room without using a tape measure. Worst case I will need to measure height in the setup procedure too and take into account Z axis. I should be able to do this by placing the Bot under remote 1 and getting height.
Let me know what you think. Because I will be traveling I will probably be drawing up ideas over the next two weeks rather than building.
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