File Coverage

blib/lib/RPi/MultiPCA9685.pm

Criterion	Covered	Total	%
statement	20	73	27.4
branch	0	8	0.0
condition			n/a
subroutine	7	10	70.0
pod	3	3	100.0
total	30	94	31.9

package RPi::MultiPCA9685;
use 5.006;
our $VERSION = '0.08';
our @ISA = qw();
use strict;
use warnings;
use POSIX qw/ceil floor/;
use RPi::I2C;
use vars qw/@dev $num_PWMPCBs/;
use Exporter 'import';
our @EXPORT_OK = qw(init_PWM setChannelPWM disablePWM);

#----------------------------------------------------------
# init all PWM PCBs - the number of boards is determined by the number of Servos (Servos /16)
#----------------------------------------------------------
sub init_PWM {
  my $i2cport=shift;
  my $i2c_address=shift;
  my $i2c_freq=shift;
  my $num_servos=shift;
  my $presc=int(25000000/(4096*$i2c_freq));# calc the prescaler value for register FEh(254)
  $num_PWMPCBs=ceil($num_servos/16);
  my $j;
  @dev=();
  for ($j=0;$j<=$num_PWMPCBs;$j++){	   # init all PWM PCBs - every 16 ports switch to the next i2c address
    $dev[$j] = RPi::I2C->new($i2c_address+$j,$i2cport);
    $dev[$j]->write_byte(16,0);            # allow to program the prescale register (only possible when PWM is inactive)
    $dev[$j]->write_byte($presc,254);      # set the calculated prescaler value to achieve the desired frequency
    $dev[$j]->write_block([32,14],0);      # init the pca9685 chip to output the PWM
  }
  return 1;
}
#----------------------------------------------------------
# Disable PWM - powers off all devices
#----------------------------------------------------------
sub disablePWM {
  return unless defined $num_PWMPCBs;      # Only disable if init has been done before
  my $j;
  for ($j=0;$j<=$num_PWMPCBs;$j++){        # disable all PWM PCBs - every 16 ports switch to the next i2c address
    $dev[$j]->write_block([0,0,0,0],250);  # disable PWM for all channels via chip Register FAh(250)
  }
  return 1;
}
#----------------------------------------------------------
# send the pwm values to the PCA9685 chip
# use the auto address increment of the chip
# Switches to the next chip if channel 15,31,47,63.... is exceeded
#----------------------------------------------------------
sub setChannelPWM {
  my $servo=shift;                         # The first servo we send moves
  my $mref=shift;                          # contains a reference for an array that contains moves for perhaps several servos
  my @split=();
  my $h;                                   # MSB of the servo move
  my $l;                                   # LSB of the servo move
  my $i=0;                                 # start with the first array element
  my $rc=0;                                # set the register count to 0
  my $startreg=6+($servo*4%64);            # the first servo register we write to modulo 70 to reset with every new board
  my $numref=$#$mref;                      # the number of positions to write
  my $splitref=\@split;                    # RPI::I2C needs all moves in an array reference
  my $brd=int($servo*2/32);                # calc the board number - the pwm board to write to
  my $obrd=$brd;                           # previous board is identical with current
  while ($i <= $numref){                   # $i points onto array element of input array (2 elements per servo)
    $brd=int(($i+$servo*2)/32);            # calc the board number
    if ($rc > 15) {
      $dev[$obrd]->write_block($splitref,$startreg); # pass all moves of the first block to the PCA9685 chip
      @split=();                           # empty, because we switch to a new board
      $rc=0;                               # continue with register reset to 0
      $startreg+=32;                       # make sure the next 8 registers will be higher
      if ($obrd < $brd) {                  # in addition a board border is reached ?
        $obrd=$brd;                        # note the change
        $startreg=6;                       # after the chip change start with register 6 of the chip (PWM 0)
      }
    }
    if ($obrd < $brd) {
      $dev[$obrd]->write_block($splitref,$startreg); # pass all moves of the first block to the PCA9685 chip
      @split=();                           # empty, because we switch to a new board
      $obrd=$brd;                          # note the change
      $startreg=6;                         # after the chip change start with register 6 of the chip (PWM 0)
      $rc=0;                               # continue with register reset to 0
    }
    $h=int($mref->[$i]) >> 8;              # calc MSB
    $l=int($mref->[$i]) & 255;             # and LSB
    push(@split,($l,$h));                  # Put all into an array
    $rc++;                                 # count the registers in buffer (must not exceed 7 since i2c lib can only write 32 byte at once)
    $i++;                                  # point to the next element
  }
  $dev[$brd]->write_block($splitref,$startreg); # pass remaining moves to the PCA9685 chip
  return 1;
}
1;
__END__