Update README.md

Author: buyAndFree

README.md

@@ -1,2 +1,23 @@
-# adafruit-vs1053-modified
-Adafruit VS1053 Library with added methods for utilising the spectrum analyser plugin
+## Modified Adafruit VS1053 for Music Maker Shield
+
+Adafruit VS1053 Library with added methods for utilising the spectrum analyser plugin.
+Uses the spectrum analyser plugin from the VSLI website (http://www.vlsi.fi/en/support/software/vs10xxplugins.html).
+
+In theory it should be compatible with other arduino shields which use the VS1053 chip.
+
+### Added methods
+
+* ```readFrequencies(uint16_t *currentVal, uint16_t *peak)``` reads the results and fills two arrays with the current and peak values of an mp3 that is being played by the shield (values are from 0 to 31 in 3dB steps).
+* ```checkRateAndBands(void)``` prints out the sampling rate and the number of frequency bands being read.
+* ```setFrequencies(int numOfBands, short *frequency)``` sets the frequencies to be read. 
+* ```readBands(void)``` returns the frequency bands.
+* ```readSamplingRate(void)``` returns the sampling rate.
+
+### How to setup your project to use the added functionality
+
+1. Download the spectrum analyser plugin from the VSLI website (http://www.vlsi.fi/en/support/software/vs10xxplugins.html)
+2. Open "spectrumAnalyzer1053b.plg" in a text editor
+3. Copy from #ifndef SKIP_PLUGIN_VARNAME (line 27) to #endif (line 152) to the top of your arduino project sketch
+4. Make sure you have included the modified library in your sketch
+5. After you initialise the mp3 player shield in your sketch add the following code: varNameOfFilePlayer.applyPatch(plugin, PLUGIN_SIZE);
+6. Use methods as required (refer to example code for reference)