CODEWITHSUNDEEP
cembeddedmapping
Lasse
Lasse

Reputation: 25

Code for pin mapping

Say I have a PCB with a header connector. Some of these pins are analog inputs, called A0-A15. These pins are connected to the ADC inputs on a MCU, but to ease the layout task, the signals were not connected with indexes one to one. So in my board specific header file I have defined the pin mapping, where BOARD_A0 refers to input A0 on the board connector followed by the corresponding index of the MCU ADC:

#define BOARD_A0            13
#define BOARD_A1            4
#define BOARD_A2            5
#define BOARD_A3            14
....

There are 16 channels total. I want to be able to dump all the channels values using a for loop, so I will need run through the whole mapping and translate each pin. For this I have the function:

unsigned int adc_get_board_channel(int channel)
{
  int adc_channel;

  switch(channel) {
    case 0:
    adc_channel = BOARD_A0;
    break;

    case 1:
    adc_channel = BOARD_A1;
    break;

    case 2:
    adc_channel = BOARD_A2;
    break;

    case 3:
    adc_channel = BOARD_A3;
    break;

    case 4:
    adc_channel = BOARD_A4;
    break;

    ....
  } 
  adc_get_channel_value(ADC,adc_channel);
}

I cant help wondering if there is a more elegant way of writing code for such pin mapping?

Upvotes: 0

Views: 451

Answers (1)

Jabberwocky
Jabberwocky

Reputation: 50883

Yes there is:

unsigned int adc_get_board_channel(int channel)
{
  static int boards[] = 
     {BOARD_A0, BOARD_A1, ..., BOARD_16};     // I let you take care of the typing

  return adc_get_channel_value(ADC, boards[channel]);
}

And BTW: in your original function there is probably a return missing right before adc_get_channel_value.

Upvotes: 5

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