SEm/escapeLab/signal generator
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= Specifications = | = Specifications = | ||
− | 4 | + | 4 sinewaves are combined to build a signal: |
− | + | * the frequency of the second one is the double of the first one's. | |
+ | * the frequency of the third one is the double of the second one's. | ||
+ | * the frequency of the fourth one is the double of the third one's. | ||
+ | |||
+ | Each sinewave is damped by a power of 2 : | ||
+ | in terms of hardware, the signal values are shifted to the right by a given number of bits. | ||
+ | The damped sinewaves are then added together to form the signal at the bottom of the following picture. | ||
+ | |||
+ | [[File:Escape sinewave sum.png|center|500px]] | ||
+ | |||
+ | Damping factors can either be 1, 1/2 and 1/256. | ||
+ | The key is the modulo 30 sum of: | ||
+ | * the power of two of the first coefficient (0 for 1, 1 for 1/2 and 8 for 1/256) | ||
+ | * two times the power of two of the second coefficient | ||
+ | * three times the power of two of the third coefficient | ||
+ | * four times the power of two of the fourth coefficient | ||
+ | |||
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<br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br> | <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br> | ||
+ | |||
PS: 1st coefficient is 0 | PS: 1st coefficient is 0 | ||
+ | |||
[[Category:Bachelor]] [[Category:SEm]] [[Category:EscapeLab]] | [[Category:Bachelor]] [[Category:SEm]] [[Category:EscapeLab]] |
Latest revision as of 17:40, 5 May 2022
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Welcome to the SEM escape lab
5th and last Key
Matching the waves
Find the coefficients and match the signal.
Specifications
4 sinewaves are combined to build a signal:
- the frequency of the second one is the double of the first one's.
- the frequency of the third one is the double of the second one's.
- the frequency of the fourth one is the double of the third one's.
Each sinewave is damped by a power of 2 : in terms of hardware, the signal values are shifted to the right by a given number of bits. The damped sinewaves are then added together to form the signal at the bottom of the following picture.
Damping factors can either be 1, 1/2 and 1/256. The key is the modulo 30 sum of:
- the power of two of the first coefficient (0 for 1, 1 for 1/2 and 8 for 1/256)
- two times the power of two of the second coefficient
- three times the power of two of the third coefficient
- four times the power of two of the fourth coefficient
PS: 1st coefficient is 0