Surveyor SRV-1 Blackfin WiFi

The Surveyor SRV-1b module provides an interface to the Surveyor SRV-1 blackfin robot. The module will request images from the Robot via 802.11 WiFi and allow you to view and process the images using RoboRealm. Motor commands based on the captured images can then be sent back to the SRV-1b robot to change its direction/speed.

Interface

Instructions

1. IP Address / Port - specify the appropriate IP address (192.168.0.15) to what you have configured your SRV-1b robot to respond to. Be sure to change the default port number 100001 if you have also changed that default configuration.

2. Manual Move - there are three ways to move the robot. The manual move allows you to press the appropriate buttons and move the robot in a direction for a period of 500 ms.

3. Motors - the second way to move the robot is to move the Motor sliders that control each of the individual motors. Note that this interface is provided to map RoboRealm variables to each of the motors to enable differential steering control from your RoboRealm control program. You can use the Min and Max editable areas to limit the range of movement that the robot will be commanded to execute. Often variables may contain irregular values due to scripting error so ensuring a limit on the motor values will ensure that your robot does not suddenly dart off in an unknown direction. A slow suggested range is 90 - 160.

The motor values range from 0 to 255 with 128 being neutral or off. Higher numbers move the robot forward while lower numbers will move the robot backwards.

4. Movement Variable - the final and third way to move the robot is to select a movement variable. This variable should contain the following values which mimic the manual move buttons. This style of automated movement control is not are refined as the individual motor command but can be useful for interfacing to interface devices like the keyboard or joystick.

0 = stop

1 = forward

2 = backward

4 = left

8 = right

16 = rotate right

32 = rotate left

5. Video - to view the video stream ensure that the checkbox next to the Video group is checked. This will start video streaming from the SRV-1. Select the appropriate size while keeping in mind that smaller sizes allow for more rapid updates. At an image size of 160x128 you should get more than 5 fps. Once the video is enabled you should start to see the image within the main RoboRealm interface. You can now proceed with machine vision based filters to process what the robot is seeing.

To further increase the video rate you can select a lower quality level for the video image. This will cause more compression of the image which results in fewer bytes being transferred to the PC system but also causes degradation in the image.

The "Pause for video" checkbox will ensure that while an image is being downloaded from the SRV-1 that its motors are off. This ensures that the robot does not move while it is blind. If you find your SRV-1 does not appear to be responding to visual stimuli or overshooting the target, select this button to reduce the motor speed and gain better control over the image processing and motor reaction loop.

6. Laser - you can test the laser lights by clicking on the "Test" button which will turn on the lasers for 5 seconds. Be sure to have the lasers pointed to a safe direction before turning testing.

To turn the lasers on and off using automatic control select a variable that when non null (i.e. it contains some text or number) the laser will turn on. Likewise when the variable is "" or is deleted the lasers will turn off.

When the lasers are turned on the Range variable will be set with the estimated distance from the robot to whatever the lasers are shining on. Note that this range variable is only valid if the lasers are turned on.

7. I/O Pins - to extend your Surveyor Robot you can use the IO Pins located on the robot to interface with other sensors or signal additional lights/LEDs/etc. To enable pin setting check the checkbox next to the I/O Pin group. The interface will then be enabled.

The GUI interface allows you to manually turn the pins off and on using the checkbox. Note that the checkbox is only enabled when the pins are set to output. The checkbox is invalid when the pin is set to input values. To automate the setting or getting of pin values assign a variable to the appropriate pin. If the pin is configured as an input then this variable will be a 1 or 0 if the input is high or low. If the pin is configured as an output then variable values of "0", "", "off", or "low" will set the pin low otherwise any other value will set it high.

8. Failsafe - to protect the robot when a loss of communication occurs the failsafe mode will ensure that the robot turns off motor commands if the wireless communication is no longer present. This can occur for a number of reasons but is normally related to the distance between the robot and the 802.11 receiver.

9. Speed - a manual selection for the speed of the robot when using the Manual Move buttons.

10. Stop - sometime the most important button in the interface is the stop button. This button will terminate the robot's movement and allow you to regain control of the robot regardless of the variables specified in the motor interfaces.

Example

Click here to check out our tutorial on the SRV-1 blackfin following a trail of orange squares.

For more information

Surveyor SRV-1 Website