Commit 5b5fd230 authored by Gallacchi Mattia's avatar Gallacchi Mattia
Browse files

Add read register 



Signed-off-by: default avatarmattia.gallacchi <mattia.gallacchi@he-arc.ch>
parent 54afefd5

lib/mcp2221a.h

+2 −0
Original line number Diff line number Diff line
@@ -104,6 +104,8 @@ namespace MCP2221A { 
         */

        void receive(uint8_t slave_addr, uint8_t *data, size_t length);



        void read_register(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data, size_t length);



        /**

         * @brief Get the slaves addresses found on the I2C bus

         *

lib/mcp2221a_i2c.cpp

+30 −2
Original line number Diff line number Diff line
@@ -159,10 +159,38 @@ namespace MCP2221A { 


        set_slave_address(slave_addr);



        while (byte_read < length) {

            if ((ret = read(fd_, data, length)) < 0 ) {

            cout << "Failed to read :" << strerror(errno) << endl;

                throw I2CMasterException(string("Failed to get data: ") + strerror(errno));

            }

            //EOF

            if (ret == 0)

                break;



            byte_read += ret;

        }

    }



    void I2CMaster::read_register(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data, size_t length)

    {

        set_slave_address(slave_addr);



        if (length < I2C_SMBUS_WORD_DATA) {

            uint16_t res = i2c_smbus_read_word_data(fd_, reg_addr);

            uint8_t h = (uint8_t) (res >> 8);

            uint8_t l = (uint8_t)res;

            data[0] = (uint8_t)(res >> 8);

            data[1] = (uint8_t)(res & 0xFF);

            return;

        }



        if (i2c_smbus_write_byte(fd_, reg_addr) < 0) {

            cout << "Failed to write register address: " << strerror(errno) << endl;

            return;

        }



        receive(slave_addr, data, length);

    }





} //namespace
 
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tests/CMakeLists.txt

+4 −1
Original line number Diff line number Diff line
@@ -4,3 +4,6 @@ project(test LANGUAGES C CXX) 


add_executable(${PROJECT_NAME} test.cpp)

target_link_libraries(${PROJECT_NAME} mcp2221a)



add_executable(main main.cpp)

target_link_libraries(main mcp2221a)
 
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tests/main.cpp

0 → 100644
+24 −0
Original line number Diff line number Diff line 
#include <iostream>

#include "mcp2221a.h"



using namespace std;



int main()

{

    MCP2221A::I2CMaster i2c;

    // vector<int> slaves = i2c.get_slaves_addresses();



    // for (auto& slave: slaves)

    //     cout << hex << "0x" << slave << dec << endl;



    unsigned char data [] = {0x01, 0x02, 0x03};

    uint8_t rx_data [2];

    i2c.read_register(0x17, 0x00, rx_data, 2);

    i2c.receive(0x17, rx_data, 2);



    for (int i = 0; i < 2; i++) {

        cout << hex << "0x" << rx_data[i] << dec << endl;

    }



    return 0;

}
 
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