Polyphonic MUSICBOX (using sound sample)

Anobium — Tue, 03 Mar 2026 14:56:18 -0000

Lifted, edit, posted.

See https://github.com/GreatCowBASIC/Demonstration_Sources/blob/main/Music

Polyphonic MUSICBOX (using sound sample)

Roger Jönsson — Tue, 03 Mar 2026 10:04:03 -0000

Thank you! -Sure! Go ahead!

Polyphonic MUSICBOX (using sound sample)

Anobium — Tue, 03 Mar 2026 07:40:53 -0000

Genius code!

May I make a YouTube video on this ?

Polyphonic MUSICBOX (using sound sample)

Roger Jönsson — Sun, 01 Mar 2026 19:09:41 -0000

A Polyphonic MUSICBOX on PIC 18F57Q84 using a sound sample as audio source.

Exploring GCBasic programming , I decided to try and make a musicbox. It resulted in a polyphonic and can play up to 8 independent voices simultaneously.
I was asked to make a demo video and figured that 3min of a PIC chip just laying on my desk was kind boring to look at, so I added a LED-bar that shows when the voices are sounding.

Here is a demo video:
-Maple Leaf Rag by Scott Joplin (Public Domain).
https://lineaudio.se/div/Musicbox%20Maple%20Leaf%20Rag.mp4
(Most of the distortion is actually added by the camera)

The 8-bit SOUND SAMPLE is stored in program memory and uploaded to RAM on start, which is then slightly faster than reading bytes with ProgramRead. The sample is played back using a Timer0 interrupt acting sample clock at 32000 times per second, running 8 voices, so sound can be made of bytes flowing though the 8-bit DAC at up to 256kB/s.
In this example all voices read from one single sound sample, which is stepped through at individual speeds (pattern of skip and repeat in the sample array) to produce the different pitches.
It would be easy to use different samples for each voice, combining percussion with different sounding instruments etc, but in this experient I decided to go for one sample making it sound kind of organ like.

The MUSIC SCORE is stored in word format and read directly using ProgramRead, stepped along by a second Timer. This conducts the voices, sets their pitches and starts them off at the right time ("Note On"). To simplify things I skipped "Note Off", so when a voice is started it just stops at its own at the end of the sample. Only when notes overlap in a voice is it stopped and restarted with the new pitch before it is finished.

Simple GLCD analogue meter

Anobium — Wed, 25 Feb 2026 16:21:08 -0000

This may help you.

GCBASIC Trigonometry Functions

(Sine, Cosine, and Tangent)

GCBASIC provides fast, integer-only trigonometric functions using lookup tables.
They work with whole-degree angles (no radians or fractions) and return scaled integer results — no floating-point library needed.

Available Precision Levels

Include File	Decimal Places	Scale Factor	sin/cos Range	tan Range (near ±90°)	Approx. Table Size
`#include <trig2places.h>`	2	×100	–100 to +100	up to ~32767	~270 bytes
`#include <trig3places.h>`	3	×1000	–1000 to +1000	up to ~32767	~550 bytes
`#include <trig4places.h>`	4	×10000	–10000 to +10000	not supported	~1100 bytes

Example Returned Values (2-place version)

sin(30) → 50 → 0.50
sin(45) → 71 → 0.71
sin(60) → 87 → 0.87
sin(90) → 100 → 1.00
cos(0) → 100
tan(45) → 100 → 1.00
tan(60) → 173 → 1.73
tan(89) → ~5729 → 57.29

Main Features

Accepts any integer angle (positive, negative, very large)
Automatically reduces angle using mod 360
Correct signs in all four quadrants
Respects odd/even properties:
sin(−θ) = −sin(θ)
cos(−θ) = cos(θ)
tan(−θ) = −tan(θ)
Very fast — usually just one table lookup + a few adjustments
No floating-point code — perfect for small PIC/AVR chips

How It Works (Deep Insight)

Normalise angle
angle = angle mod 360 → result is 0° to 359°
Handle negative angles & determine sign
sin and tan are odd functions → flip sign and negate angle if negative
cos is even → only negate angle if negative
Apply quadrant-based sign rules (II/III negative for cos, etc.)
Fold to reference angle (0°–90°)
0–90 → use as is
90–180 → 180 − angle
180–270 → angle − 180
270–360 → 360 − angle
Lookup value
sin and cos use the same table (sineTab) containing sin(0°) to sin(90°)
tan uses a separate tanTab
Cosine shortcut
cos(θ) = sin(90° − θ)
→ cosine just reads the sine table at (90 − reference angle)
Apply final sign
Return table value × calculated sign

This clever folding + co-function trick keeps memory use low and speed high.

Displaying Results on LCD/Serial (Common Helper)

sub printTrig(value as integer)
    dim s as string, sign as string
    sign = ""
    if value < 0 then
        sign = "-"
        value = -value
    end if
    s = str(value)
    select case len(s)
        case 1:  print sign + "0.0" + s          ' 7 → 0.07
        case 2:  print sign + "0."  + s          ' 71 → 0.71
        case 3:  print sign + left(s,1) + "." + right(s,2)  ' 100 → 1.00
        case 4:  print sign + left(s,2) + "." + right(s,2)  ' 173 → 1.73
    end select
end sub

(Extend the select case for 3-place and 4-place versions.)

Recommendation

Use <trig2places.h> for most projects — smallest and fastest
Choose <trig3places.h> when you want noticeably better accuracy (e.g. 0.866 instead of 0.87 for sin(60°))
Use <trig4places.h> only when tangent is not needed and you want maximum sin/cos resolution

These routines are lightweight, efficient, and still one of the best fixed-point trig solutions for 8-bit microcontrollers in the GCBASIC ecosystem.

Simple GLCD analogue meter

Willem — Wed, 25 Feb 2026 14:47:07 -0000

Thanks for the help Anobium, yes it works fine, its just that I would have liked to know what that Sin and Cos stuff is doing. I will have a look at the help files.

Simple GLCD analogue meter

Anobium — Tue, 24 Feb 2026 16:27:35 -0000

There is a range to Sin(). Your random number must not exceed the range of mathematical Sin(). See the Help.

From the photo ..did you get working?

Simple GLCD analogue meter

Willem — Tue, 24 Feb 2026 14:46:51 -0000

Sorry for posting 100 times, I was not sure if it posts or what.
The 100 hits and misses were like this, I put random numbers in the 2 equation's and then compile it, load it into the pic and see what happens on the screen, until it was coming right, took quite some time.

Simple GLCD analogue meter

Willem — Mon, 23 Feb 2026 16:42:23 -0000

A Voltmeter with a GLCD 240x320 with a ili9341 chip, thanks to Stan and Anobium for the original code. Can someone please explain how this part of the code works, I managed to make it work on the bigger screen, but with hundreds of hits and misses:

     sub plotdial

  xend = 166 + radius  * sin (angle)/185
  yend = 165 - radius  * cos (angle)/185

  pset (xend,yend,0XFFE0)


  Here is the working code on a BIG screen

'''You can change the microcontroller, the GLCD and the analogue port.
'''To change the microcontroller simply change the #chip statement
'''To change the GLCD replace GLCD definition
'''To change the analogue port change the ADCChannelSelected constant
' Many thanks to Stan and Anobium who wrote this in 2017. I only adapte
'it to work with 16F887 pic and a Temu GLCD 240 x 320 screen

   #chip 16f887,20
#include <glcd.h>
#option explicit
#INCLUDE <TRIG2PLACES.H>

 'Defines for ILI9341
#define GLCD_TYPE GLCD_TYPE_ILI9341

'Setup the GLCD to 16F887
#define GLCD_DC PORTC.0
#define GLCD_CS PORTC.1
#define GLCD_RESET PORTC.2
#define GLCD_DI PORTC.4
#define GLCD_DO PORTC.5
#define GLCD_SCK PORTC.3

'Specify the type of GLCD

#define GLCD_WIDTH 320
#define GLCD_HEIGHT 240
#define GLCD_PROTECTOVERRUN
   'FONT SIZE
#define GLCD_OLED_FONT 'The constant is required to support OLED fonts
GLCDfntDefaultSize = 2 ' 8 pixels high = 1 , 2 = 16 pixels high

GLCDRotate (landscape)
GLCDCLS ILI9341_BLACK

        'analogue port selection
    #define ADCChannelSelected AN0
    #define ADSpeed LowSpeed

dim xcentre,ycentre,xend,old_xend,yend,old_yend as word
DIM RADIUS as word
dim angle,old_angle,adcval as word
dim volts as string * 4

xcentre=168  'X en Y of needle
ycentre=160

       ;draw dial
GLCDCLS
box (25,20,310,210,0xf800)
BOX (135,175,205,200,0XF800)

   '''dail size''''
for radius=260 to 200
  dial
next radius

              '''DAIL decoration '''
GLCDDrawChar (40,95,asc("0")):GLCDDrawChar (285,95,asc("5"))
 GLCDprint (82,55,"1",0xffff):GLCDprint (135,27,"2",0xffff)
 GLCDprint (190,25,"3",0xffff): GLCDprint (240,50,"4",0xffff)

       '''length of needle'''''
radius = 250     ' lengte van naald
angle=1
anglecheck

;main
do
  old_angle=angle
;--- DVM
  adcval=ReadAD(ADCChannelSelected)
  angle=adcval/2
;
  adcval=adcval*100
  adcval=adcval/51
  volts=str(adcval)

  if adcval<10 then
    volts="0.0"+left(volts,1,1)
    goto volt_format_done
  end if
  if adcval<100 then
    volts="0."+mid(volts,1,2)
  else
    volts=left(volts,1,1)+"."+mid(volts,2,2)
  end if
  volt_format_done:
;---
  anglecheck
  old_xend = xcentre + radius  * sin (old_angle)/255
  old_yend = ycentre - radius  * cos (old_angle)/255
  xend = xcentre + radius  * sin (angle)/255
  yend = ycentre - radius  * cos (angle)/255
  if old_angle<>angle then ;-- update screen if volts has changed
;   erase old needle
    line (xcentre,ycentre,old_xend,old_yend,0)'black

;   '''Print Volts'''
    GLCDPrint (140,180,volts,0x07e0) ;print Voltage
    GLCDprint (190,180,"V",0x07e0)

;   '''draw new needle'''
    line (xcentre,ycentre,xend,yend,0xf800)
    wait 110 ms
  end if
loop
  ;end main

sub plotdial  ''''Dail height,beginning and end posistion''''

  xend = 166 + radius  * sin (angle)/185
  yend = 165 - radius  * cos (angle)/185

  pset (xend,yend,0XFFE0)
end sub
;
sub dial

         ''''dail''''
  for angle= 296 to 359
    plotdial
  next angle
;
  for angle= 0 to 65
    plotdial
  next angle
end sub

;

sub anglecheck
if angle>127 then
angle =angle-127
else
angle =296+angle
end if
end sub

'''Enjoy'''

Simple GLCD analogue meter

Willem — Mon, 23 Feb 2026 16:42:20 -0000

     sub plotdial

  xend = 166 + radius  * sin (angle)/185
  yend = 165 - radius  * cos (angle)/185

  pset (xend,yend,0XFFE0)


  Here is the working code on a BIG screen

   #chip 16f887,20
#include <glcd.h>
#option explicit
#INCLUDE <TRIG2PLACES.H>

 'Defines for ILI9341
#define GLCD_TYPE GLCD_TYPE_ILI9341

'Setup the GLCD to 16F887
#define GLCD_DC PORTC.0
#define GLCD_CS PORTC.1
#define GLCD_RESET PORTC.2
#define GLCD_DI PORTC.4
#define GLCD_DO PORTC.5
#define GLCD_SCK PORTC.3

'Specify the type of GLCD

#define GLCD_WIDTH 320
#define GLCD_HEIGHT 240
#define GLCD_PROTECTOVERRUN
   'FONT SIZE
#define GLCD_OLED_FONT 'The constant is required to support OLED fonts
GLCDfntDefaultSize = 2 ' 8 pixels high = 1 , 2 = 16 pixels high

GLCDRotate (landscape)
GLCDCLS ILI9341_BLACK

        'analogue port selection
    #define ADCChannelSelected AN0
    #define ADSpeed LowSpeed

dim xcentre,ycentre,xend,old_xend,yend,old_yend as word
DIM RADIUS as word
dim angle,old_angle,adcval as word
dim volts as string * 4

xcentre=168  'X en Y of needle
ycentre=160

       ;draw dial
GLCDCLS
box (25,20,310,210,0xf800)
BOX (135,175,205,200,0XF800)

   '''dail size''''
for radius=260 to 200
  dial
next radius

              '''DAIL decoration '''
GLCDDrawChar (40,95,asc("0")):GLCDDrawChar (285,95,asc("5"))
 GLCDprint (82,55,"1",0xffff):GLCDprint (135,27,"2",0xffff)
 GLCDprint (190,25,"3",0xffff): GLCDprint (240,50,"4",0xffff)

       '''length of needle'''''
radius = 250     ' lengte van naald
angle=1
anglecheck

;main
do
  old_angle=angle
;--- DVM
  adcval=ReadAD(ADCChannelSelected)
  angle=adcval/2
;
  adcval=adcval*100
  adcval=adcval/51
  volts=str(adcval)

  if adcval<10 then
    volts="0.0"+left(volts,1,1)
    goto volt_format_done
  end if
  if adcval<100 then
    volts="0."+mid(volts,1,2)
  else
    volts=left(volts,1,1)+"."+mid(volts,2,2)
  end if
  volt_format_done:
;---
  anglecheck
  old_xend = xcentre + radius  * sin (old_angle)/255
  old_yend = ycentre - radius  * cos (old_angle)/255
  xend = xcentre + radius  * sin (angle)/255
  yend = ycentre - radius  * cos (angle)/255
  if old_angle<>angle then ;-- update screen if volts has changed
;   erase old needle
    line (xcentre,ycentre,old_xend,old_yend,0)'black

;   '''Print Volts'''
    GLCDPrint (140,180,volts,0x07e0) ;print Voltage
    GLCDprint (190,180,"V",0x07e0)

;   '''draw new needle'''
    line (xcentre,ycentre,xend,yend,0xf800)
    wait 110 ms
  end if
loop
  ;end main

sub plotdial  ''''Dail height,beginning and end posistion''''

  xend = 166 + radius  * sin (angle)/185
  yend = 165 - radius  * cos (angle)/185

  pset (xend,yend,0XFFE0)
end sub
;
sub dial

         ''''dail''''
  for angle= 296 to 359
    plotdial
  next angle
;
  for angle= 0 to 65
    plotdial
  next angle
end sub

;

sub anglecheck
if angle>127 then
angle =angle-127
else
angle =296+angle
end if
end sub

'''Enjoy'''

Recent posts to User Submitted Projects, Demos & Guides

Polyphonic MUSICBOX (using sound sample)

Polyphonic MUSICBOX (using sound sample)

Polyphonic MUSICBOX (using sound sample)

Polyphonic MUSICBOX (using sound sample)

Simple GLCD analogue meter

GCBASIC Trigonometry Functions

Available Precision Levels

Example Returned Values (2-place version)

Main Features

How It Works (Deep Insight)

Displaying Results on LCD/Serial (Common Helper)

Recommendation

Simple GLCD analogue meter

Simple GLCD analogue meter

Simple GLCD analogue meter

Simple GLCD analogue meter

Simple GLCD analogue meter