mcp3xxx.h

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#pragma once
 
#include <PropWare/PropWare.h>
#include <PropWare/serial/spi/spi.h>
 
namespace PropWare {
 
class MCP3xxx {
    public:
        enum class Channel {               CHANNEL_0,               CHANNEL_1,               CHANNEL_2,               CHANNEL_3,CHANNEL_4,CHANNEL_5,CHANNEL_6,CHANNEL_7,
        };
 
        enum class ChannelDiff {               DIFF_0_1,               DIFF_1_0,               DIFF_2_3,               DIFF_3_2,DIFF_4_5,DIFF_5_4,DIFF_6_7,DIFF_7_6
        };
 
        enum class PartNumber {MCP300x = 11,MCP320x = 13,MCP330x = 14
        };
 
    public:
        MCP3xxx (SPI &spi, const PropWare::Pin::Mask cs, MCP3xxx::PartNumber partNumber,
                 const bool alwaysSetSPIMode = false)
                : m_spi(&spi),
                  m_alwaysSetMode(alwaysSetSPIMode),
                  m_dataWidth(static_cast<uint8_t>(partNumber)) {
            this->m_spi->set_mode(SPI_MODE);
            this->m_spi->set_bit_mode(SPI_BITMODE);
 
            this->m_cs.set_mask(cs);
            this->m_cs.set();
            this->m_cs.set_dir_out();
        }
 
        void always_set_spi_mode (const bool alwaysSetMode) {
            this->m_alwaysSetMode = alwaysSetMode;
        }
 
        uint16_t read (const MCP3xxx::Channel channel) {
            int8_t   options;
            uint16_t dat;
 
            options = START | static_cast<int8_t>(SINGLE_ENDED) | static_cast<int8_t>(channel);
 
            // Two dead bits between output and input - see page 19 of datasheet
            options <<= 2;
 
            if (this->m_alwaysSetMode) {
                this->m_spi->set_mode(MCP3xxx::SPI_MODE);
                this->m_spi->set_bit_mode(MCP3xxx::SPI_BITMODE);
            }
 
            this->m_cs.clear();
            this->m_spi->shift_out(OPTION_WIDTH, (uint32_t) options);
            dat = (uint16_t) this->m_spi->shift_in(this->m_dataWidth);
            this->m_cs.set();
 
            return dat;
        }
 
        uint16_t read_diff (const MCP3xxx::ChannelDiff channels) {
            int8_t   options;
            uint16_t dat;
 
            options = START | static_cast<int8_t>(DIFFERENTIAL) | static_cast<int8_t>(channels);
 
            // Two dead bits between output and input - see page 19 of datasheet
            options <<= 2;
 
            if (this->m_alwaysSetMode) {
                this->m_spi->set_mode(SPI_MODE);
                this->m_spi->set_bit_mode(SPI_BITMODE);
            }
 
            this->m_cs.clear();
            this->m_spi->shift_out(OPTION_WIDTH, (uint32_t) options);
            dat = (uint16_t) this->m_spi->shift_in(this->m_dataWidth);
            this->m_cs.set();
 
            return dat;
        }
 
    protected:
        static const SPI::Mode    SPI_MODE    = SPI::Mode::MODE_2;
        static const SPI::BitMode SPI_BITMODE = SPI::BitMode::MSB_FIRST;
 
        static const uint8_t START        = BIT_4;
        static const uint8_t SINGLE_ENDED = BIT_3;
        static const uint8_t DIFFERENTIAL = 0;
        static const uint8_t OPTION_WIDTH = 7;
 
    protected:
        SPI           *m_spi;
        PropWare::Pin m_cs;
        bool          m_alwaysSetMode;
        uint8_t       m_dataWidth;
};
 
}