adxl330- code to pic16f877

[nachum]

Hi,


I took the code from MikroElektronika and I make compiler,
and I get error messages.
Anyone know what changes to make to not receive error messages.

I attached the message...

Using driver C:\Program Files\HI-TECH Software\PICC\9.70\bin\picc.exe

Make: The target "C:\Test\3\Start.p1" is out of date.
Executing: "C:\Program Files\HI-TECH Software\PICC\9.70\bin\picc.exe" --pass1 C:\Test\3\Start.c -q --chip=16F877A -P --runtime=default --opt=default -D__DEBUG=1 -g --asmlist "--errformat=Error [%n] %f; %l.%c %s" "--msgformat=Advisory[%n] %s" "--warnformat=Warning [%n] %f; %l.%c %s"
Warning [107] C:\Test\3\Start.c; 5.7 illegal # directive "device"
Warning [107] C:\Test\3\Start.c; 6.7 illegal # directive "device"
Warning [107] C:\Test\3\Start.c; 7.6 illegal # directive "FUSES"
Warning [107] C:\Test\3\Start.c; 8.6 illegal # directive "FUSES"
Warning [107] C:\Test\3\Start.c; 9.6 illegal # directive "FUSES"
Warning [107] C:\Test\3\Start.c; 10.6 illegal # directive "FUSES"
Warning [107] C:\Test\3\Start.c; 11.6 illegal # directive "FUSES"
Warning [107] C:\Test\3\Start.c; 12.6 illegal # directive "FUSES"
Warning [107] C:\Test\3\Start.c; 13.6 illegal # directive "FUSES"
Warning [361] C:\Test\3\Start.c; 41.1 function declared implicit int
Warning [361] C:\Test\3\Start.c; 50.10 function declared implicit int
Warning [361] C:\Test\3\Start.c; 57.1 function declared implicit int
Warning [356] C:\Test\3\Start.c; 103.23 implicit conversion of float to integer
Warning [356] C:\Test\3\Start.c; 107.23 implicit conversion of float to integer
Warning [356] C:\Test\3\Start.c; 111.24 implicit conversion of float to integer
Make: The target "C:\Test\3\delay.p1" is up to date.
Executing: "C:\Program Files\HI-TECH Software\PICC\9.70\bin\picc.exe" -oSensorFinal.cof -mSensorFinal.map --summary=default --output=default Start.p1 delay.p1 --chip=16F877A -P --runtime=default --opt=default -D__DEBUG=1 -g --asmlist "--errformat=Error [%n] %f; %l.%c %s" "--msgformat=Advisory[%n] %s" "--warnformat=Warning [%n] %f; %l.%c %s"
Licensed for evaluation purposes only.
This licence will expire on Sat, 10 Apr 2010.
HI-TECH C Compiler for PIC10/12/16 MCUs (PRO Mode) V9.70
Copyright (C) 2009 Microchip Technology Inc.
Error [500] ; 0. undefined symbols:
_Adc_Read(SensorFinal.obj) _Usart_Write(SensorFinal.obj) _strConstCpy(SensorFinal.obj)

********** Build failed! **********

 

[Wilksey]

Unless you use the Mikro C Compiler you will not be able to compile the code, there are violations for directives, variable types and libraries.

Your best bet is to re-write the code if you really need to use HITECH C.

Unless you know your libraries it is not always easy to port code between compilers when it comes to MCU's

HTH

Wilksey

 

[nachum]

I downloaded the compiler "mikroC PRO for PIC" from MikroElektronika and I still see error messages.
I attached the messages.

0 1 mikroCPIC1618.exe -MSF -DBG -pP16F877A -DL -O11111114 -fo8 -N"C:\Test\5\Read_Angles.mcppi" -SP"C:\Program Files\Mikroelektronika\mikroC PRO for PIC\defs\" -SP"C:\Program Files\Mikroelektronika\mikroC PRO for PIC\Uses\P16\" -SP"C:\Test\5\" "Read_Angles1.c" "Read_Angles.c" "__Lib_Math.mcl" "__Lib_MathDouble.mcl" "__Lib_System.mcl" "__Lib_Delays.mcl" "__Lib_CType.mcl" "__Lib_CString.mcl" "__Lib_CStdlib.mcl" "__Lib_CMath.mcl" "__Lib_Conversions.mcl" "__Lib_Sprinti.mcl" "__Lib_Sprintl.mcl" "__Lib_Time.mcl" "__Lib_Trigonometry.mcl" "__Lib_Button.mcl" "__Lib_Keypad4x4.mcl" "__Lib_Manchester.mcl" "__Lib_OneWire.mcl" "__Lib_PS2.mcl" "__Lib_Sound.mcl" "__Lib_SoftI2C.mcl" "__Lib_SoftSPI.mcl" "__Lib_SoftUART.mcl" "__Lib_ADC_A_C.mcl" "__Lib_EEPROM.mcl" "__Lib_FLASH_RW.mcl" "__Lib_I2C_c34.mcl" "__Lib_PWM_c21.mcl" "__Lib_SPI_c345.mcl" "__Lib_UART_c67.mcl" "__Lib_PortExpander.mcl" "__Lib_CANSPI.mcl" "__Lib_CF.mcl" "__Lib_GlcdFonts.mcl" "__Lib_Glcd.mcl" "__Lib_LcdConsts.mcl" "__Lib_Lcd.mcl" "__Lib_RS485.mcl" "__Lib_T6963C.mcl" "__Lib_SPIGlcd.mcl" "__Lib_SPILcd.mcl" "__Lib_SPILcd8.mcl" "__Lib_SPIT6963C.mcl" "__Lib_EthEnc28j60.mcl"
0 1138 Available RAM: 352 [bytes], Available ROM: 8192 [bytes]
0 304 C:/Test/5/Read_Angles1.c:26: error: Can't open include file "16f877a.h"
0 304 #include <16F877A.h>
0 304 C:/Test/5/Read_Angles1.c:27: error: Unknown #directive "device"
0 304 #device *=16
0 304 C:/Test/5/Read_Angles1.c:28: error: Unknown #directive "device"
0 304 #device adc=10
0 304 C:/Test/5/Read_Angles1.c:29: error: Unknown #directive "FUSES"
0 304 #FUSES NOWDT
0 304 C:/Test/5/Read_Angles1.c:30: error: Unknown #directive "FUSES"
0 304 #FUSES HS
0 304 C:/Test/5/Read_Angles1.c:31: error: Unknown #directive "FUSES"
0 304 #FUSES NOPUT
0 304 C:/Test/5/Read_Angles1.c:32: error: Unknown #directive "FUSES"
0 304 #FUSES NOPROTECT
0 304 C:/Test/5/Read_Angles1.c:33: error: Unknown #directive "FUSES"
0 304 #FUSES NODEBUG
0 304 C:/Test/5/Read_Angles1.c:34: error: Unknown #directive "FUSES"
0 304 #FUSES NOBROWNOUT
0 304 C:/Test/5/Read_Angles1.c:35: error: Unknown #directive "FUSES"
0 304 #FUSES NOLVP
0 304 C:/Test/5/Read_Angles1.c:36: error: Unknown #directive "use"
0 304 #use delay(clock=20000000)
0 304 C:/Test/5/Read_Angles1.c:37: error: Unknown #directive "use"
0 304 #use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8)
0 304 C:/Test/5/Read_Angles1.c:39: error: Can't open include file "kbd.c"
0 304 #include <KBD.C>
0 304 C:/Test/5/Read_Angles1.c:40: error: Can't open include file "ctype.h"
0 304 #include <ctype.h>
0 304 C:/Test/5/Read_Angles1.c:41: error: Can't open include file "float.h"
0 304 #include <float.h>
0 304 C:/Test/5/Read_Angles1.c:42: error: Can't open include file "math.h"
0 304 #include <math.h>
0 304 C:/Test/5/Read_Angles1.c:43: error: Can't open include file "string.h"
0 304 #include <string.h>
0 304 C:/Test/5/Read_Angles1.c:44: error: Can't open include file "lcd204.c"
0 304 #include "LCD204.c"
0 304 18 errors in preprocessor.
0 304 C:/Test/5/Read_Angles.c:27: error: Can't open include file "16f877a.h"
0 304 #include <16F877A.h>
0 304 C:/Test/5/Read_Angles.c:28: error: Unknown #directive "device"
0 304 #device *=16
0 304 C:/Test/5/Read_Angles.c:29: error: Unknown #directive "device"
0 304 #device adc=10
0 304 C:/Test/5/Read_Angles.c:30: error: Unknown #directive "FUSES"
0 304 #FUSES NOWDT
0 304 C:/Test/5/Read_Angles.c:31: error: Unknown #directive "FUSES"
0 304 #FUSES HS
0 304 C:/Test/5/Read_Angles.c:32: error: Unknown #directive "FUSES"
0 304 #FUSES NOPUT
0 304 C:/Test/5/Read_Angles.c:33: error: Unknown #directive "FUSES"
0 304 #FUSES NOPROTECT
0 304 C:/Test/5/Read_Angles.c:34: error: Unknown #directive "FUSES"
0 304 #FUSES NODEBUG
0 304 C:/Test/5/Read_Angles.c:35: error: Unknown #directive "FUSES"
0 304 #FUSES NOBROWNOUT
0 304 C:/Test/5/Read_Angles.c:36: error: Unknown #directive "FUSES"
0 304 #FUSES NOLVP
0 304 C:/Test/5/Read_Angles.c:37: error: Unknown #directive "use"
0 304 #use delay(clock=20000000)
0 304 C:/Test/5/Read_Angles.c:38: error: Unknown #directive "use"
0 304 #use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8)
0 304 C:/Test/5/Read_Angles.c:40: error: Can't open include file "kbd.c"
0 304 #include <KBD.C>
0 304 C:/Test/5/Read_Angles.c:41: error: Can't open include file "ctype.h"
0 304 #include <ctype.h>
0 304 C:/Test/5/Read_Angles.c:42: error: Can't open include file "float.h"
0 304 #include <float.h>
0 304 C:/Test/5/Read_Angles.c:43: error: Can't open include file "math.h"
0 304 #include <math.h>
0 304 C:/Test/5/Read_Angles.c:44: error: Can't open include file "string.h"
0 304 #include <string.h>
0 304 C:/Test/5/Read_Angles.c:45: error: Can't open include file "lcd204.c"
0 304 #include "LCD204.c"
0 304 18 errors in preprocessor.
0 102 Finished (with errors): 23 îøõ 2010, 17:05:16 Read_Angles.mcppi

 

[Wilksey]

Do you have a link to the code or can you post the code files I have the Mikro C Compiler I can see if it will compile on my system.

Wilksey

 

[nachum]

CODE FOR THE ADXL330- Undeclared identifier 'Usart_Write'

Hi,
Thanks for your help
I've included the code


Why do I get Undeclared identifier ?

0 1 mikroCPIC1618.exe -MSF -DBG -pP16F877A -DL -O11111114 -fo8 -N"C:\Test\2\Read_Angles.mcppi" -SP"C:\Program
0 1138 Available RAM: 352 [bytes], Available ROM: 8192 [bytes]
0 126 All files Preprocessed in 1 ms
0 122 Compilation Started Read_Angles.c
44 324 Undeclared identifier 'Usart_Write' in expression Read_Angles.c
46 324 Undeclared identifier 'Usart_Write' in expression Read_Angles.c
47 324 Undeclared identifier 'Usart_Write' in expression Read_Angles.c
181 324 Undeclared identifier 'Usart_Init' in expression Read_Angles.c
0 102 Finished (with errors): 24 îøõ 2010, 20:09:52 Read_Angles.mcppi

// * Project name:
//     Read_Angles
// * Copyright:
//     (c) MikroElektronika, 2008.
// * Description:
//     This project demonstrates Calibration and Reading the Accel Board outputs
//     using the ADConversion library.
//     On transition to the next stage program waits for user 
//     to bring the Vcc to RD0 pin.
// * Test configuration:
//     MCU:             PIC16F877A
//     Dev.Board:       EasyPIC5
//     Oscillator:      HS, 8.000 MHz
//     Ext. Modules:    Accel board Xout=RA0, Yout=RA1 and Zout=RA2
//     SW:              mikroC v8
// * NOTES:
//     - Usart jumpers = On
//     - When connecting the Vcc and Gnd consult the board schematics -
//       if you don't do this properly you may DAMAGE the Accel board !!!
//     - Connect the X-out to RA0, Y-out to RA1 and Z-out to RA2.
//     - PORTA LEDs and pull-up/down switches = Off 
//     - pull-down PORTD and set the buttons jumper to Vcc
//     - arcsin function return value range is [-pi/2, pi/2] or [-90 deg, 90 deg].
// --- Messages---
#include "built_in.h"

const char *msg1="Board to pos    ";
const char *msg2="and press RD0   ";
const char *msg3="Zero G values : ";
const char *msg4="One G values :  ";
const char *msg5="Angles:";
const char *msg6="X=     Y=     Z=    ";

char positionNo=1;

signed int x, y, zz;
signed int zeroG_x, zeroG_y, zeroG_z;
signed int oneG_x, oneG_y, oneG_z;
signed int meas_x, meas_y, meas_z;
char text[32];

void Usart_Write_Text(char* wr_txt) {
  while (*wr_txt)
    Usart_Write(*wr_txt++);
    
  Usart_Write(10);
  Usart_Write(13);
}

// --- Copying strings from ROM to RAM
void strConstCpy(char *dest, const char *source) {
  while(*source)
  *dest++ = *source++ ;
  
  *dest = 0 ;
}

void DoMeasureXYZ() {
  meas_x = Adc_Read(0);   // Measure X_out
  meas_y = Adc_Read(1);   // Measure Y_out
  meas_z = Adc_Read(2);   // Measure Z_out
}

void WriteXYZ(signed int wr_x, signed int wr_y, signed int wr_z) {

  strConstCpy(text,msg6);

  if (wr_x < 0) {
     text[2] = '-';
     wr_x = -wr_x;
     }
  else   
     text[2] = wr_x/1000+48;
     
  text[3] = (wr_x/100)%10+48;
  text[4] = (wr_x/10)%10+48;
  text[5] = wr_x%10+48;


  if (wr_y < 0) {
     text[9] = '-';
     wr_y = -wr_y;
     }
  else   
     text[9] = wr_y/1000+48;
     
  text[10] = (wr_y/100)%10+48;
  text[11] = (wr_y/10)%10+48;
  text[12] = wr_y%10+48;
  
  
  if (wr_z < 0) {
     text[16] = '-';
     wr_z = -wr_z;
     }
  else
     text[16] = wr_z/1000+48;

  text[17] = (wr_z/100)%10+48;
  text[18] = (wr_z/10)%10+48;
  text[19] = wr_z%10+48;
  
  Usart_Write_Text(text);
}

void Calibrate() {

  strConstCpy(text,msg1);         //  1__ Put the Accel board in the position 1 :
  text[13] = positionNo++ + 48;   //      parallel to earth's surface
  Usart_Write_Text(text);         //      Z_axis is vertical with Z label UP
  strConstCpy(text,msg2);         //      to measure the Zero Gravity values for X and Y
  Usart_Write_Text(text);         //      and 1G Z value
  while (PORTD.F0 == 0);          //      Loop until RD0 becomes 1

  DoMeasureXYZ();
  zeroG_x = meas_x;
  zeroG_y = meas_y;
  oneG_z  = meas_z;
  Delay_ms(1000);


  strConstCpy(text,msg1);         //  2__ Put the Accel board in the position 2 :
  text[13] = positionNo++ + 48;   //      X_axis is vertical with X label UP
  Usart_Write_Text(text);
  strConstCpy(text,msg2);         //      to measure the 1G X value
  Usart_Write_Text(text);         //      and Zero Gravity value for Z
  while (PORTD.F0 == 0);          //      Loop until RD0 becomes 1

  DoMeasureXYZ();
  oneG_x = meas_x;
  zeroG_z = meas_z;
  Delay_ms(1000);

  strConstCpy(text,msg1);         //  3__ Put the Accel board in the position 3 :
  text[13] = positionNo++ + 48;   //      Y_axis is vertical with Y label UP
  Usart_Write_Text(text);
  strConstCpy(text,msg2);         //      to measure the 1G Y value
  Usart_Write_Text(text);
  while (PORTD.F0 == 0);          //      Loop until RD0 becomes 1

  DoMeasureXYZ();
  oneG_y = meas_y;

  strConstCpy(text,msg3);         // Display ZeroG values
  Usart_Write_Text(text);
  WriteXYZ(zeroG_x, zeroG_y, zeroG_z);
  Delay_ms(3000);

  strConstCpy(text,msg4);         // Display OneG values
  Usart_Write_Text(text);
  WriteXYZ(oneG_x, oneG_y, oneG_z);
  Delay_ms(3000);
}

void Read_Angles() {
 double div_x, x_rad, div_y, y_rad, div_z, z_rad ;

  DoMeasureXYZ();
  div_x = (float)(meas_x-zeroG_x) / (oneG_x-zeroG_x);  // measured_G / one_G
  x_rad = asin( div_x );                               // x angle in radians
  x = (x_rad*180) / 3.14;                              // x angle in degrees

  div_y = (float)(meas_y-zeroG_y) / (oneG_y-zeroG_y);  // measured_G / one_G
  y_rad = asin( div_y );                               // y angle in radians
  y = (y_rad*180) / 3.14;                              // y angle in degrees

  div_z = (float)(meas_z-zeroG_z) / (oneG_z-zeroG_z);  // measured_G / one_G
  z_rad = asin( div_z );                               // z angle in radians
  zz = (z_rad*180) / 3.14;                             // z angle in degrees

  WriteXYZ(x, y, zz);
}

void main() {
  CMCON  = 7;
  ADCON1 = 0x00;      // configure VDD as Vref, RA0, RA1 and RA2 as analog inputs
  TRISA  = 0b00000111;
  PORTD = 0;          // configure RD0 is digital input
  TRISD = 1;

  Usart_Init(9600);   // Initialize USART module
  Delay_ms(100);
  
  Calibrate();

  strConstCpy(text,msg5);     // Display Angles
  Usart_Write_Text(text);
                 
  //--- main loop
  while(1) {
    Read_Angles();
    Delay_ms(1000);
    }
}

 

[Wilksey]

The reason is it was designed for Mikro C, Mikro C Pro has changed it's libraries etc, it is a pain as it isn't backwards compatible.

I have attached a zip file with the compiled code and a compilable example for MIKRO C PRO 1.65 (I hope they haven't changed anything since!)

Regards

Wilksey

 

[nachum]

Thank you for the speed


How do I open the file?

 

[Wilksey]

ZIP file? just download JZip or another freeware zip extractor.

 

[nachum]

I opened the ZIP. I meant the file inside the ZIP I can not open it.

 

[nachum]

miKroC converted to MPLAB

Do you know what changes to make to work with MPLAB?

const char *msg1="Board to pos    ";
const char *msg2="and press RD0   ";
const char *msg3="Zero G values : ";
const char *msg4="One G values :  ";
const char *msg5="Angles:";
const char *msg6="X=     Y=     Z=    ";

char positionNo=1;

signed int x, y, zz;
signed int zeroG_x, zeroG_y, zeroG_z;
signed int oneG_x, oneG_y, oneG_z;
signed int meas_x, meas_y, meas_z;
char text[32];

void UART_Write_Text(char* wr_txt) {
  while (*wr_txt)
    UART1_Write(*wr_txt++);

  UART1_Write(10);
  UART1_Write(13);
}

// --- Copying strings from ROM to RAM
void strConstCpy(char *dest, const char *source) {
  while(*source)
  *dest++ = *source++ ;

  *dest = 0 ;
}

void DoMeasureXYZ() {
  meas_x = Adc_Read(0);   // Measure X_out
  meas_y = Adc_Read(1);   // Measure Y_out
  meas_z = Adc_Read(2);   // Measure Z_out
}

void WriteXYZ(signed int wr_x, signed int wr_y, signed int wr_z) {

  strConstCpy(text,msg6);

  if (wr_x < 0) {
     text[2] = '-';
     wr_x = -wr_x;
     }
  else
     text[2] = wr_x/1000+48;

  text[3] = (wr_x/100)%10+48;
  text[4] = (wr_x/10)%10+48;
  text[5] = wr_x%10+48;


  if (wr_y < 0) {
     text[9] = '-';
     wr_y = -wr_y;
     }
  else
     text[9] = wr_y/1000+48;

  text[10] = (wr_y/100)%10+48;
  text[11] = (wr_y/10)%10+48;
  text[12] = wr_y%10+48;


  if (wr_z < 0) {
     text[16] = '-';
     wr_z = -wr_z;
     }
  else
     text[16] = wr_z/1000+48;

  text[17] = (wr_z/100)%10+48;
  text[18] = (wr_z/10)%10+48;
  text[19] = wr_z%10+48;

  UART1_Write_Text(text);
}

void Calibrate() {

  strConstCpy(text,msg1);         //  1__ Put the Accel board in the position 1 :
  text[13] = positionNo++ + 48;   //      parallel to earth's surface
  UART1_Write_Text(text);         //      Z_axis is vertical with Z label UP
  strConstCpy(text,msg2);         //      to measure the Zero Gravity values for X and Y
  UART1_Write_Text(text);         //      and 1G Z value
  while (PORTD.F0 == 0);          //      Loop until RD0 becomes 1

  DoMeasureXYZ();
  zeroG_x = meas_x;
  zeroG_y = meas_y;
  oneG_z  = meas_z;
  Delay_ms(1000);


  strConstCpy(text,msg1);         //  2__ Put the Accel board in the position 2 :
  text[13] = positionNo++ + 48;   //      X_axis is vertical with X label UP
  UART1_Write_Text(text);
  strConstCpy(text,msg2);         //      to measure the 1G X value
  UART1_Write_Text(text);         //      and Zero Gravity value for Z
  while (PORTD.F0 == 0);          //      Loop until RD0 becomes 1

  DoMeasureXYZ();
  oneG_x = meas_x;
  zeroG_z = meas_z;
  Delay_ms(1000);

  strConstCpy(text,msg1);         //  3__ Put the Accel board in the position 3 :
  text[13] = positionNo++ + 48;   //      Y_axis is vertical with Y label UP
  UART1_Write_Text(text);
  strConstCpy(text,msg2);         //      to measure the 1G Y value
  UART1_Write_Text(text);
  while (PORTD.F0 == 0);          //      Loop until RD0 becomes 1

  DoMeasureXYZ();
  oneG_y = meas_y;

  strConstCpy(text,msg3);         // Display ZeroG values
  UART1_Write_Text(text);
  WriteXYZ(zeroG_x, zeroG_y, zeroG_z);
  Delay_ms(3000);

  strConstCpy(text,msg4);         // Display OneG values
  UART1_Write_Text(text);
  WriteXYZ(oneG_x, oneG_y, oneG_z);
  Delay_ms(3000);
}

void Read_Angles() {
double div_x, x_rad, div_y, y_rad, div_z, z_rad ;

  DoMeasureXYZ();
  div_x = (float)(meas_x-zeroG_x) / (oneG_x-zeroG_x);  // measured_G / one_G
  x_rad = asin( div_x );                               // x angle in radians
  x = (x_rad*180) / 3.14;                              // x angle in degrees

  div_y = (float)(meas_y-zeroG_y) / (oneG_y-zeroG_y);  // measured_G / one_G
  y_rad = asin( div_y );                               // y angle in radians
  y = (y_rad*180) / 3.14;                              // y angle in degrees

  div_z = (float)(meas_z-zeroG_z) / (oneG_z-zeroG_z);  // measured_G / one_G
  z_rad = asin( div_z );                               // z angle in radians
  zz = (z_rad*180) / 3.14;                             // z angle in degrees

  WriteXYZ(x, y, zz);
}

void main() {
  CMCON  = 7;
  ADCON1 = 0x00;      // configure VDD as Vref, RA0, RA1 and RA2 as analog inputs
  TRISA  = 0b00000111;
  PORTD = 0;          // configure RD0 is digital input
  TRISD = 1;

  Uart1_Init(9600);   // Initialize USART module
  Delay_ms(100);

  Calibrate();

  strConstCpy(text,msg5);     // Display Angles
  UART1_Write_Text(text);

  //--- main loop
  while(1) {
    Read_Angles();
    Delay_ms(1000);
    }
}

 

[Wilksey]

There is a hex file and a few other files including the project file for Mikro C Pro, you can open the C file in wordpad or Mikro C Itself.

I think there are quite a few changes to make it work in MPLAB as you would need to use the HI TECH C Compiler.

Wilksey

 

[bandulad82]

Bandula (Sri Lanka)

Dear Gayan , Glad to see in this site ,and I joined right now ,your 64x8 design is marvelous ,but I don't know any thing about PIC programming,please can you send me the HEX file.

Thanks Bandula