src/libs/Adc.h

   1 /*
   2       This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl).
   3       Smoothie is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
   4       Smoothie is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
   5       You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>.
   6 */
   7
   8
   9
  10 #ifndef ADC_H
  11 #define ADC_H
  12
  13 #include "PinNames.h" // mbed.h lib
  14
  15 #include <cmath>
  16
  17 class Pin;
  18 namespace mbed {
  19     class ADC;
  20 }
  21
  22 // define how many bits of extra resolution required
  23 // 2 bits means the 12bit ADC is 14 bits of resolution
  24 #define OVERSAMPLE 2
  25
  26 class Adc
  27 {
  28 public:
  29     Adc();
  30     void enable_pin(Pin *pin);
  31     unsigned int read(Pin *pin);
  32
  33     static Adc *instance;
  34     void new_sample(int chan, uint32_t value);
  35     // return the maximum ADC value, base is 12bits 4095.
  36 #ifdef OVERSAMPLE
  37     int get_max_value() const { return 4095 << OVERSAMPLE;}
  38 #else
  39     int get_max_value() const { return 4095;}
  40 #endif
  41
  42 private:
  43     PinName _pin_to_pinname(Pin *pin);
  44     mbed::ADC *adc;
  45
  46     static const int num_channels= 6;
  47 #ifdef OVERSAMPLE
  48     // we need 4^n sample to oversample and we get double that to filter out spikes
  49     static const int num_samples= powf(4, OVERSAMPLE)*2;
  50 #else
  51     static const int num_samples= 8;
  52 #endif
  53     // buffers storing the last num_samples readings for each channel
  54     uint16_t sample_buffers[num_channels][num_samples];
  55 };
  56
  57 #endif