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DE GENDRE, Raphaëlle, 03/23/2016 11:48 AM

1 2 DE GENDRE, Raphaëlle 
h1. Implementation
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In order to test our communication chain, we decided to implement a receiver to see if we could receive the temperature and print it on the screen. To do that, we started with the receiver that was implemented to receive the GPS signal in a former project since we use the same waveform. In order to apply the receiver to our case, we had to remove the part that was linked to the RTTY system with the Baudot and ASCII Coding. Since we  wanted an integer to indicate the temperature, that is what we implemented.





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h2. Subdemod.vi





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We decided to use the same start sequence that the one of the GPS project and to use as well Manchester coding. Therefore, we only changed the last part about Baudot and ASCII coding. 





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p=. !{width:50%}startsequence.jpg!





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Figure 1: Waiting for start sequence





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p=. !{width:50%}subdemod2.jpg!





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Figure 2: Conversion from Manchester to bits





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p=. !{width:55%}subdemod3.jpg!





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Figure 3: Conversion from bits to integer





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To convert the bits to integers, we use the vi MT Pack bits.vi. This vi takes as an input a bit array, the number of bits per integer(7 in our case), and the type of integer(2 choices:signed or unsigned). We chose to work with signed integers according to the program on the development board. You can as well choose whether you are working with LSB (least significant bit first) or MSB (most significant bit first). In our case, we are working with MSB. At the output, it gives an array of integer which is as well the output of this vi.