living with the lab
using a radio frequency transmitter and receiver
pair costs approximately $20 from http://xenon-tech.com
© David Hall 2013
windmill pumping water for cows – west Texas
living with the lab
challenge: drive your robot through the maze
end
• place robot at the edge of the plywood at the start and say GO!!
• stop the watch when the robot hits the back of the parking spot at the end
wind turbines in California
start
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living with the lab
challenge details
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use the transmitter / receiver pair to allow remote control of your robot
see how fast you can navigate through the maze (take turns with your partner!!!)
give your ID to the instructor to check out a transmitter / receiver pair
complete challenge in teams of two
teams can time each other’s runs
write team members names and times on the white board after completing a run
you can use the playing field on a first come basis
give priority to other teams if you have already had two attempts (share after that)
wind turbines in California
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living with the lab
data sheet for transmitter: XETX02A
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economical short range RF transmission (> 45 meters)
designed for automotive applications
low power consumption (typically: 10nA when not transmitting)
powered by a small 12V battery
transmission power of 10mW
data rate: 4 kB/s
available in frequencies of 315MHz and 435MHz available
wind turbines in California
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living with the lab
data sheet for receiver: XERE02A
1 – 5V
2 – data valid
3 – GND
4 – output D
5 – output B
6 – output C
7 – output A
8 – antenna (18cm of wire for 433MHz)
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2
3
4
5
6
7
economical short range RF transmission
miniature size of 47 x 20 x 8 mm
low power consumption (typically: 4mA)
operating temperature range of -10°C to +70°C
target operating voltage: 5V (should be between 4V and 6V)
available in frequencies of 315MHz and 435MHz available
wind turbines in California
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living with the lab
transmitters and receivers have been “paired”
8
7
6
5
4
3
2
1
pull high
pull low
solder the middle row to the
upper row to pull pin 7 high
(this pair is labeled as #7)
NOTE: this has already been done . . . no need for you to solder!
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living with the lab
play nice 
receiver 7
• transmitter 7 controls receiver 7
• using another transmitter at the same time jams
communications between transmitter 7 and receiver 7
wind turbines in California
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living with the lab
getting started
• look at the data sheet above for wiring the receiver
• some tips are available at the following link:
• http://www2.latech.edu/~dehall/LWTL/home/content_projects.html
• find “servos – manually creating pulses” to recall wiring your servos
• find “servos – using the servo library” to assist with programming
• find the presentations that remind you how to use if and if/else statements
• ask your instructor for help if you get stuck for a while
you can do this!!!
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living with the lab
transmitter / receiver pairs 1 to 8
• The following slides show how the eight pins can be pulled high or low
through soldering to create 30 unique transmitter / receiver pairings
• There are 28 = 256 possible pairings
• If all 256 are desired, it would be nice to treat the pins as digits of a binary
number . . . the soldering scheme here is just for convenience
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
pair 1
8
7
6
5
4
3
2
1
pair 5
8
7
6
5
4
3
2
1
pair 2
8
7
6
5
4
3
2
1
pair 6
8
7
6
5
4
3
2
1
pair 3
8
7
6
5
4
3
2
1
pair 7
8
pair 4
7
6
5
4
3
2
1
pair 8
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living with the lab
transmitter / receiver pairs 9 to 16
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
pair 9
8
7
6
5
4
3
2
1
pair 13
8
7
6
5
4
3
2
1
pair 10
8
7
6
5
4
3
2
1
pair 14
8
7
6
5
4
3
2
1
pair 11
8
7
6
5
4
3
2
1
pair 15
8
pair 12
7
6
5
4
3
2
1
pair 16
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transmitter / receiver pairs 17 to 30
living with the lab
8
7
6
5
4
3
2
8
1
7
6
5
4
3
2
1
pair 24
pair 17
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
pair 18
8
7
6
5
4
3
2
1
pair 25
8
7
6
5
4
3
2
1
pair 19
8
7
6
5
4
3
2
1
pair 26
8
7
6
5
4
3
2
1
pair 20
8
7
6
5
4
3
2
1
pair 27
8
7
6
5
4
3
2
1
pair 21
8
7
6
5
4
3
2
1
pair 28
8
7
6
5
4
3
2
1
pair 22
8
7
6
5
4
3
2
1
pair 29
8
pair 23
7
6
5
4
3
2
1
pair 30
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