LPC2132 read AD ports

Development Boards MicroMod
1

hello, i am new here and asking for help to do this:

i use an LPC2132 to generate video chars, and need to read the output of an analog sensor that gives 0,3v-3,2v and on other AD port read the voltage of an 12v battery, the only thing that i know is that i have to make an voltage divider for the bat.

can anyone help me with some example to result in a function like “volts=read_ad(port_x)”

thanks in advance for your help

2

Here’s some code for an LPC2148:

//-------------------- initialisation stuff --------------------// 

void Initialise(void)
{
  volatile unsigned int x, i, j, c;
  unsigned char temp[10];


  // initialise PLL

  PLL0CFG=0x24;      // Cclk = 60Mhz
  PLL0CON=0x01;
  PLL0FEED=0xAA;
  PLL0FEED=0x55;
  while(!(PLL0STAT & 0x0400))
	;
  PLL0CON=0x3;
  PLL0FEED=0xAA;
  PLL0FEED=0x55;

  // initialise MAM and VPB

  MAMTIM=0x3;       // 3 cycles to read from FLASH
  MAMCR=0x2;        // MAM functions fully enabled
  APBDIV=0x02;      // Pclk = 30MHz

   //initialise pclk (3 MHz)
  unsigned long pclk = liblpc2000_get_pclk(liblpc2000_get_cclk(OSCILLATOR_CLOCK_FREQUENCY));
 
  // initialise TIMER0
  T0TCR = 0; /* Reset timer 0 */
  T0PR = 0; /* Set the timer 0 prescale counter */
  T0MR0 = pclk/50 - 1; /* Set time 0 match register to generate an interrupt every 20 ms */
  T0MCR = 3; /* Generate interrupt and reset counter on match */
  T0TCR = 1; /* Start timer 0 */

  // setup CTL stuff for Timer 0
  ctl_set_isr(4, 0, CTL_ISR_TRIGGER_FIXED, timer0ISR, 0);
  ctl_unmask_isr(4);

  x = ctl_get_ticks_per_second();

 

  // initialise ADC

  PINSEL0 = PINSEL0 | 0x00003C00; // P0.5, P0.6 setup for AD0.7, AD1.0 inputs
                // bits  11:10  13:12 
                //         11    11
  PINSEL1 = 0x15000000; // P0.28, P0.29, P0.30 set for AD0.1, AD0.2, AD0.3 inputs
                  // bits  25:24  27:26  30:29
                  //         01    01      01
  AD0CR = 0x00200604; // enable ADC, 11 clocks/10 bits, ADC clock = 4.286 MHz
  AD1CR = 0x00208001;

  // initialise GPIOs

  IO1DIR |= 0x000F0000; // P1.16, P1.17, P1.18, P1.19 outputs
  IO0DIR |= 0x00800100; // P0.23, P0.8 outputs
  IO0SET |= 0x00800100; // set them high
 
  //initialise timer ticks
  ticks = 0; 
  
  // clear status flags
  status = 0;
  panic_state = 0;

  // initialise Rx circular buffer
  uart1_rx_extract_idx = uart1_rx_insert_idx = 0;

  

  // initialise watchdog timer
  // timer period = (Tpclk x 4) x WDTC value
  WDTC = 0xFFFFFFFF;  // set constant reload value
  WDMOD = 0x00000003; // watchdog reset mode
  WDFEED = 0xAA;      // start watchdog
  WDFEED = 0x55;

/*
  //test UART1 comms with motor controller
  while(1)
  {
    _puts1("EN");  //enable responses ("OK") to commands
    if (uart1_rx_buffer[0] == 'O')
      break;
    delay(100);
  }
*/

 // initialise UART0 (RxD0 P0.1, TXD0 P0.0)

  U0LCR = 0x83;  // set DLAB. 8N1
  U0DLL = 0xC3;  // set for 9600 Baud  
  U0DLM = 0x00;  // set for 9600 Baud  
  U0LCR &= ~0x80; // disable DLAB  
  U0FCR = 0x00000001; // enable FIFO
  PINSEL0 = PINSEL0 & (~0xF)| 0x5;  // enable UART0 pins

  // initialise UART1 (RxD1 P0.9, TxD1 P0.8

  U1LCR = 0x83; // 8 bit, 1 stop bit, no parity, enable DLAB
  U1DLL = 0xC3; // set for 9600 baud
  U1DLM = 0x00;
  U1LCR &= ~0x80; // disable DLAB
  U1FCR = 1;      // enable FIFO
  PINSEL0 = PINSEL0 & ~(0xFFFF << 16) | (0x5555 << 16);


  // Setup UART0 RX interrupt
  
  /*
  ctl_set_isr(7, 1, CTL_ISR_TRIGGER_FIXED, uart0ISR, 0);
  ctl_unmask_isr(7);
  U0IER = 1;
  */
  
  //send "ANSW0" to motor and disable it
  _puts1("ANSW0");
  _puts1("DI");

  // Setup UART1 RX interrupt
  ctl_set_isr(7, 1, CTL_ISR_TRIGGER_FIXED, uart1ISR, 0);
  ctl_unmask_isr(7);
  U1IER = 1;



  // enable global interrupts
  ctl_global_interrupts_enable();

}

//-------------------------- getAnalogueInput_AD0 function ---------------//

unsigned short int getAnalogueInput_AD0(unsigned char channel)
{
  unsigned short int val;

  //start conversion (for selected channel)
  AD0CR = (AD0CR & 0xFFFFFF00) | (1 << channel) | (1 << 24);

  //wait until done
  while((AD0GDR & 0x80000000) == 0)
    ;

  // get ADC data
  val = ((AD0GDR & 0x0000FFC0)) >> 6;       
  return(val);
}

Delete the stuff you don’t need.

Leon

3

first of all, thanks

can i use some of that code in LPC2132, the addresses are the same?

can you simplify the code to only use to read the AD ports?

i am newbie in microcontrollers :oops:

thanks

4

You need to check the data sheet for the addresses. Delete the unwanted code yourself.

Leon