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It was almost as if David designed this product quite specifically for my dual-motorized Sip&Puff controlled robotic kayak project. You will understand why when you read the text that follows below. One of several YouTube videos of the system can be viewed at:
http://www.youtube.com/watch?v=3sfYnretWJ4
So far, I have operated my project in Ventura Harbor for over 20 hours. Several times I ran it at full power for over 20 minutes at a time. I expect that each motor draws a maximum of only 30 AMPS, however all components are sealed inside of a 2.5 gallon semi-watertight container that is exposed to direct sunlight. I have yet to see the RS160D go into reduced power mode due to high temp, but I do notice that the fan comes on after some time, as I would expect.
There are a few omissions and misprints in the User's Manual, but only one that required me to contact David for clarification. Experienced hobbyists should be able to accomplish everything from the information supplied, and David responded VERY quickly to my communications. Specifically, the commands necessary to control the Driver in PWM Mode via serial commands are:
Serial.println( "@0sm1" ); //Only required once for each channel
Serial.println( "@0sj0" ); //To set channel 0 to Serial Control mode
Serial.println( "@0stx" ); //For channel 0, x = Speed -255 to 255. 0 = Stop
Following is a detailed description of my project that I wrote earlier.
A highly disabled (quadriplegic) person can fully control the kayak via a SIP & PUFF Switch (Picture Steven Hawking or Christopher Reeve in their wheelchair).
The on-board Arduino Duemilanove Microcontroller puts the Motor Driver into Serial Input Control Mode and accepts Sip&Puff Switch inputs from the Rider. It then sends appropriate Serial Commands to the Motor Driver to operate the two Drive Motors.
Split-second (0.1 - 0.6 seconds) Sips and Puffs control Left and Right Turning, respectively, and slightly longer (0.6 - 2.5 seconds) Sips & Puffs control REV and FWD movement. Even longer Sips and Puffs Stop the motors or command them equally to Full Speed. Steering is accomplished via differential motor speed.
At any time, the Safety Observer can (turn on the RC Transmitter and) transmit a Full Throttle command which the Arduino detects via this Receiver Channel being connected directly to it. The Arduino then sends Serial commands to the Motor Driver to put it into RC Input Control Mode. The Safety Observer now has full direct control of the Motor Driver via the AILERON and ELEVATOR channels of the Receiver being connected directly to the RC Inputs of the Driver (in MIXED Mode). The kayak is now essentially a large robot.
If the Safety Observer decides to pass control back to the Rider, a Throttle Off command is Transmitted, or the transmitter is simply turned off. The Arduino detects this condition and sends Serial Input Control Mode Commands to the Motor Driver giving control of the Motor Driver back to the Rider via Sip&Puff inputs into the Arduino. Note that the Arduino controls the Motor Driver via Serial Commands Only.
The Rudder Channel of the Receiver is reserved to actuate high-current switches which will physically disconnect the Drive Motors from the Motor Driver.
Top speed is just under 3.7 MPH, according to my GPS. After 4 hours and 6.2+ miles, the motors were still running strong, producing ~3.3 MPH into the wind, and the main battery still showed 12.15 volts. The Motor Driver and Arduino Controller, as well as the Sip&Puff Interface, will continue to operate down to 5 volts.
My total cost for this project so far, not including the Spectrum DX7 Transmitter, is around $1300, with the biggest expenses being: Motor Driver ($430), 2 Min Kota Trolling Motors ($240), Aluminum ($135), Battery ($90), and Charger ($60). Also: LEDs, Cables, Connectors, Switches, and I.C.s ($175+), RC Receiver ($60), Cam Bolts ($40), Backup Arduino uController ($35), etc... Note that I actually did make it all the way through my Design & Development process without blowing up the original Arduino!
Although I have been contemplating this project since 2006, obtaining the Arduino uController really gave me a jump-start. Finding the RS160D Motor Driver is what really enabled me to complete this project in record time. I officially started working on it in mid-June of this year (06/17/09). I had the project completely working on August 20, 2009. Compare this to the Cal Poly Solo Quad project (Google: Cal Poly Solo Quad) which I undertand took 40 people 6 years and $30,000 in grant money to finish.
Cal Poly engineers considered Remote Control Assist impossible to incorporate into their design. The RS160D made this feature an absolute "no-brainer" to incorporate into my project, and the ability to command the driver between Serial and RC Command Modes cemented the successful implementation of my design.
Rating:  [5 of 5 Stars!] |
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