TEST SYSTEM FOR PAYLOAD-OBC INTERFACE IN PISAT

Transcription

1 PES Institute Of Technology, Bangalore CRUCIBLE OF RESEARCH AND INNOVATION LAB TEST SYSTEM FOR PAYLOAD-OBC INTERFACE IN PISAT Mr. Dhananjay V Kumar Mr. Adarsh R Mr. Dayanand B M Mr. Mahendra M Nayak Dr. V K Agrawal

2 AN OVERVIEW OF PISAT PISAT- Pesit Imaging Satellite Low cost nano-satellite. Designed and developed at the Crucible of Research and Innovation Lab, PES Institute of Technology. Polar Sun-synchronous Low Earth Orbit (LEO). One payload- GOMSPACE Nanocam C1U.

3 NEED FOR A TEST SYSTEM Independent testing of the On Board Computer(OBC) and The test system simulates all the functions of the OBC and the. Hence both OBC and can be individually tested by using the simulators Allows Bench and Environmental testing This can be used for the bench and environmental testing of the satellite before integrating the actual payload onto it.

4 INTERFACE BETWEEN PAYLOAD AND OBC Nanocam runs on free RTOS and supports FTP for data transfer. OBC runs on custom Real Time Executive (RTE) developed by Students at PESIT. Providing support for FTP on OBC is non trivial. GOM Space provided a new firmware on Nanocam that allows access to memory on Nanocam using CSP protocol.

5 OBJECTIVE : Serial Interface Serial Interface Arduino UNO simulating OBC I 2 C Interface Arduino UNO simulating

6 OBJECTIVE : Testing of Serial Interface Arduino UNO simulating OBC I 2 C Interface

7 OBJECTIVE : Serial Interface Testing of OBC I 2 C Interface Arduino UNO simulating

8 FLOW OF COMMANDS Cam_Snap Cam_Store Cam_List Cam_Peek Snap an Image Store the picture Get Details about the Image Get Image Data

9 FRONT-END APPLICATION Developed using Microsoft Visual Basic 2010 Express Edition. The Application runs on the system used for communicating with the Arduino. Allows initiating testing and also viewing test results.

10 COMMANDS CSP_Snap : {0x0A,0x62,0x00,0x00} To take a picture. A successful snap reply will output to the first 50 bytes of the received buffer.

11 Serial Interface Testing of OBC I 2 C Interface Command Sent Arduino UNO simulating

12 Serial Interface Testing of OBC Command Recognized I 2 C Interface Arduino UNO simulating

13 ACKNOWLEDGING SNAP

14 COMMANDS CSP_Store : {0x0A,0x62,0xC0,0x00,0x00,0x02,0x01,'p','1','.','j','p','g } To store the just snapped picture to the internal memory the cam store <filename> command.

15 ACKNOWLEDGING STORE

16 Testing of OBC Serial Interface Size of image I 2 C Interface Arduino UNO simulating

17 Testing of OBC Serial Interface 119 bytes of Data Stored I 2 C Interface Arduino UNO simulating

18 COMMANDS CSP_List : {0x0A,0x61,0xC0,0x00} Returns data about the picture file requested for, which includes size of the file, format, base address (location on memory).

19 Testing of OBC Serial Interface I 2 C Interface Reply to List Arduino UNO simulating

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21 COMMANDS CSP_Peek : {0x0A,0x60,0x00,0x00,0x04,0x11,0x8F,0xA3,0xA0,0x78} Returns 119 bytes from the base address mentioned

22 Testing of OBC Serial Interface I 2 C Interface 119 bytes of data Arduino UNO simulating

23 Testing of OBC Serial Interface Request next Pack of data I 2 C Interface Arduino UNO simulating

24 Testing of OBC Serial Interface 119 bytes of Data Stored I 2 C Interface Arduino UNO simulating

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26 Testing of Command to initiate test Serial Interface Arduino UNO simulating OBC I 2 C Interface

27 Testing of Serial Interface Arduino UNO simulating OBC I 2 C Interface Response to Commands from OBC

28 Testing of Image data sent for viewing Serial Interface Arduino UNO simulating OBC I 2 C Interface

29 Verification

30 Future Work Baud rate of the serial communication between Arduino and computer limits the speed of I2C communication while testing. Insufficient memory on the Arduino board restricts the entire image data being stored in the board. Both these problems may be solved if the Arduino simulating the is integrated with an SD card.

31 Conclusion The test system that was designed and developed was verified thoroughly for its functionalities. The system allowed independent testing of OBC and. The system will be used for bench and environmental testing before the integration of the satellite into the launch vehicle.

32 SUMMARY The system simulated the responses of the Nanocam to the following commands: Snap Store List Peek - To snap a picture - To store the image in a specific format. - To return information regarding image. - To return requested number of bytes of image data. The system verified the responses from the Nanocam and displayed the received image.

33 GALLERY

34 GALLERY