Chris Wilson / Mbed 2 deprecated LCD_Spectrum_Analyzer

This program gets 7-band frequency data from the MSGEQ7 library and displays a 7-band, 2-row bar graph on an LCD display using custom characters.

Dependencies:   MSGEQ7 TextLCD mbed

Note this program uses great LCD custom character code from Lluis Nadal to create the LCD bar graphs: http://mbed.org/users/lnadal/code/Lcd_Custom_Char/

Files at this revision

API Documentation at this revision

Revision 0:ee637039cb58, committed 2013-10-16

Comitter:
chrisisthefish
Date:
Wed Oct 16 06:56:41 2013 +0000
Commit message:
Initial creation

Changed in this revision

MSGEQ7.lib Show annotated file Show diff for this revision Revisions of this file
TextLCD.lib Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MSGEQ7.lib	Wed Oct 16 06:56:41 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/chrisisthefish/code/MSGEQ7/#974a4855a7f8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextLCD.lib	Wed Oct 16 06:56:41 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/simon/code/TextLCD/#44f34c09bd37

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Oct 16 06:56:41 2013 +0000
@@ -0,0 +1,99 @@
+// LCD_Spectrum_Analyzer
+// Created by Chris Wilson
+// 10/16/2013
+
+// NOTE: Contains LCD Custom Character code from Lluis Nadal
+
+#include "mbed.h"
+#include "MSGEQ7.h"
+#include "TextLCD.h"
+
+#define MAX 15
+
+MSGEQ7 eq(p13, p14, p15); //reset, strobe, analog
+TextLCD lcd(p30, p29, p28, p27, p26, p25); // rs, e, d4-d7
+
+// Defines LCD bus to write data.
+BusOut Lcd_pins(p28, p27, p26, p25); // d4, d5, d6, d7
+DigitalOut rs_pin(p30); // LCD pin rs (register select.)
+DigitalOut e_pin(p29);  // LCD pin e (enable).
+
+//This data is 8 LCD characters representing an 8-level bar graph
+char levels[8][8] = {
+    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x1F},
+    {0x00,0x00,0x00,0x00,0x00,0x00,0x1F,0x1F},
+    {0x00,0x00,0x00,0x00,0x00,0x1F,0x1F,0x1F},
+    {0x00,0x00,0x00,0x00,0x1F,0x1F,0x1F,0x1F},
+    {0x00,0x00,0x00,0x1F,0x1F,0x1F,0x1F,0x1F},
+    {0x00,0x00,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F},
+    {0x00,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F},
+    {0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F}
+};
+
+/* Code from Lluis Nadal
+http://mbed.org/users/lnadal/code/Lcd_Custom_Char/
+*/
+// Because we use 4 bit LCD, data must be sent in two steps.
+void writePort(int value) {
+
+    Lcd_pins = value >> 4;  // Shifts 4 bit right.
+    wait(0.000040f); // Wait 40us.
+    e_pin = 0;
+    wait(0.000040f);
+    e_pin = 1;
+    Lcd_pins = value;
+    wait(0.000040f);
+    e_pin = 0;
+    wait(0.000040f);
+    e_pin = 1;
+}
+
+/* Code from Lluis Nadal
+http://mbed.org/users/lnadal/code/Lcd_Custom_Char/
+*/
+void createChars(){
+    for (int j=0; j<8; j++) {
+        rs_pin = 0; // We send a command.
+
+        /* 0X40 is the initial CGRAM address. Because each character needs a total amount of 8 memory 
+        locations, we increment addres in 8 units after each character.
+        */
+        writePort(0x40+8*j);
+
+        // Writes data.
+        rs_pin = 1; // We send data.
+        
+        for (int i=0; i<8; i++) {
+            writePort(levels[j][i]);
+        }
+    }
+}
+
+
+int main() {
+    int i = 0;
+    lcd.cls();
+    createChars();
+    
+    while(1) {
+        eq.readInt(MAX); //Read in frequency data, mapped to a max number of 15
+        
+        for(i = 0; i < 7; i++){
+            
+            lcd.locate(i, 1); //Draw second (lower) row first
+            if(eq.freqDataInt[i] > 7){ //Is the lower level maxed out?
+                lcd.putc(7); // If maxed out, display full bars
+            }else{
+                lcd.putc(eq.freqDataInt[i]);
+            }
+            
+            lcd.locate(i, 0); //Draw first (upper) row
+            if(eq.freqDataInt[i] < 8){
+                lcd.putc(32); //If empty, draw a space (' ')
+            }else{
+                lcd.putc(eq.freqDataInt[i] - 8);
+            }
+        }
+        
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Wed Oct 16 06:56:41 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/a9913a65894f
\ No newline at end of file