transistance
New Member
Im using a 16f877 PIC to drive an LCD screen which will display the frequency of a note played by a guitar - basically a guitar tuner.
I am having trouble with the frequency detection. There are couple ideas that I came up withafter running the signal through LM386 with 20x gain)
1. Run the LM386 output through 74LS14 schmitt trigger (I have already tried this and i have miserably failed at getting output from schmitt trigger). Take output from 74LS14; time the pulse and detect frequency with 16f877.
2. Run the LM386 output through LM2917 frequency-to-voltage converter and use ADC module of 16f877. (Unfortunately, I am not familiar with this IC and have no clue how to convert audible frequencies into voltage; so any input is highly appreciated)
Which one is a more accurate method? Is there a better way to capture the frequency? Is there specific way to use 74LS14 that I am not aware of? Any schematics or C and R values to help me with LM2917 available?
Thanks in advance,
~transistance
I am having trouble with the frequency detection. There are couple ideas that I came up withafter running the signal through LM386 with 20x gain)
1. Run the LM386 output through 74LS14 schmitt trigger (I have already tried this and i have miserably failed at getting output from schmitt trigger). Take output from 74LS14; time the pulse and detect frequency with 16f877.
2. Run the LM386 output through LM2917 frequency-to-voltage converter and use ADC module of 16f877. (Unfortunately, I am not familiar with this IC and have no clue how to convert audible frequencies into voltage; so any input is highly appreciated)
Which one is a more accurate method? Is there a better way to capture the frequency? Is there specific way to use 74LS14 that I am not aware of? Any schematics or C and R values to help me with LM2917 available?
Thanks in advance,
~transistance