For my hobby project I try to make a quadcopter which balances itself with the MPU-6050. The flight controller shall be the FPGA Altera cyclone IV, because its fun. I'm coding it in VHDL.
Anyway I'm stuck on the I2C communication with the MPU-6050. As bases I used the I2C master VHDL code from: https://www.digikey.com/eewiki/pages/viewpage.action?pageId=10125324.
I try to read the gyro registers and print them out on 8 leds just to see if I have some communication coming in.
I have tried to run with a 1Hz prescaler all the I2C phases in the state machine and light up some leds just to see if all phases are run through. This is the case. I have assigned the pins 2.5V default, I use 10k pull up resistors. The MPU6050 works perferct on an arduino.
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity mpu6050_2 is
port( clk_50 : in std_logic;
areset : in std_logic;
i2c_SDA : INOUT STD_LOGIC;
i2c_SCL : INOUT STD_LOGIC;
leds : out std_LOGIC_VECTOR(7 downto 0)
);
end entity mpu6050_2;
architecture struc of mpu6050_2 is
component i2c_master is
GENERIC(
input_clk : INTEGER := 50_000_000;
bus_clk : INTEGER := 400_000);
PORT(
clk : IN STD_LOGIC;
reset_n : IN STD_LOGIC;
ena : IN STD_LOGIC;
addr : IN STD_LOGIC_VECTOR(6 DOWNTO 0);
rw : IN STD_LOGIC;
data_wr : IN STD_LOGIC_VECTOR(7 DOWNTO 0);
busy : OUT STD_LOGIC;
data_rd : OUT STD_LOGIC_VECTOR(7 DOWNTO 0);
ack_error : BUFFER STD_LOGIC;
sda : INOUT STD_LOGIC;
scl : INOUT STD_LOGIC);
end component ;
type machine is (config1, config2, gyroH, gyroL);
signal state : machine:= config1; --current state
signal SDA_int : std_LOGIC;
signal SCL_int : std_LOGIC;
signal i2c_ena : std_LOGIC;
signal i2c_busy : std_LOGIC;
signal busy_prev : std_LOGIC;
signal i2c_rw : std_LOGIC;
signal i2c_data_wr : STD_LOGIC_VECTOR(7 DOWNTO 0);
signal gyro_data : std_LOGIC_VECTOR(15 downto 0);
signal i2c_data_rd : std_LOGIC_VECTOR (7 downto 0);
signal i2c_addr : STD_LOGIC_VECTOR(6 DOWNTO 0);
begin
process(areset, clk_50)
VARIABLE busy_cnt : INTEGER := 0; --keeps track of i2c busy signals during transaction
begin
if areset = '0' then
busy_cnt := 0;
i2c_ena <= '0';
state <= config1;
elsif rising_edge(clk_50) then
case state is
when config1 =>
busy_prev <= i2c_busy;
if (busy_prev = '0' and i2c_busy = '1') then
busy_cnt := busy_cnt + 1;
end if;
case busy_cnt is
when 0 =>
i2c_ena <= '1';
i2c_addr <= "1101000"; --MPU6050 adress
i2c_rw <= '0'; --write
i2c_data_wr <= x"6B"; -- hex6B powermanagement
when 1 =>
i2c_rw <= '0'; --write
i2c_data_wr <= "00000000"; -- ON with internal clock
when 2 =>
i2c_ena <= '0';
if(i2c_busy = '0') then
busy_cnt := 0;
state <= config2;
end if;
when others => NULL;
end case;
when config2 =>
busy_prev <= i2c_busy;
if (busy_prev = '0' and i2c_busy = '1') then
busy_cnt := busy_cnt + 1;
end if;
case busy_cnt is
when 0 =>
i2c_ena <= '1';
i2c_addr <= "1101000"; --MPU6050 adress
i2c_rw <= '0'; --write
i2c_data_wr <= x"1B"; -- Gyro config
when 1 =>
i2c_rw <= '0'; --write
i2c_data_wr <= "00000000"; -- 250 degree/sec, no self test
when 2 =>
i2c_ena <= '0';
if(i2c_busy = '0') then
busy_cnt := 0;
state <= gyroH;
end if;
when others => NULL;
end case;
when gyroH =>
busy_prev <= i2c_busy;
if (busy_prev = '0' and i2c_busy = '1') then
busy_cnt := busy_cnt + 1;
end if;
case busy_cnt is
when 0 =>
i2c_ena <= '1';
i2c_addr <= "1101000"; --MPU6050 adress
i2c_rw <= '0'; --write
i2c_data_wr <= x"43"; -- hex43 GYRO_OUT[15:8]
when 1 =>
i2c_rw <= '1'; --read
when 2 =>
i2c_ena <= '0';
if(i2c_busy = '0') then
gyro_data(15 downto 8) <= i2c_data_rd;
busy_cnt := 0;
state <= gyroL;
end if;
when others => NULL;
end case;
when gyroL =>
busy_prev <= i2c_busy;
if (busy_prev = '0' and i2c_busy = '1') then
busy_cnt := busy_cnt + 1;
end if;
case busy_cnt is
when 0 =>
i2c_ena <= '1';
i2c_addr <= "1101000"; --MPU6050 adress
i2c_rw <= '0'; --write
i2c_data_wr <= x"44"; -- hex44 GYRO_OUT[7:0]
when 1 =>
i2c_rw <= '1'; --read
when 2 =>
i2c_ena <= '0';
if(i2c_busy = '0') then
gyro_data(7 downto 0) <= i2c_data_rd;
busy_cnt := 0;
state <= gyroH;
end if;
when others => NULL;
end case;
end case;
end if;
end process;
u0: i2c_master
port map(clk => clk_50, reset_n => areset, ena => i2c_ena, addr => i2c_addr, rw => i2c_rw, data_wr => i2c_data_wr, busy => i2c_busy, data_rd => i2c_data_rd
, sda => SDA_int, scl => SCL_int);
leds(7) <= gyro_data(0); --D4
leds(6) <= gyro_data(1); -- D5
leds(5) <= gyro_data(4); -- D6
leds(4) <= gyro_data(7); -- D7
leds(3) <= gyro_data(8); -- D8
leds(2) <= gyro_data(11); -- D9
leds(1) <= gyro_data(13); -- D10
leds(0) <= gyro_data(15); -- D11
i2c_SDA <= SDA_int;
i2c_SCL <= SCL_int;
end struc;
Result: all the leds dont change status despite if i rotate the MPU6050. So no communication. Can anyone help me what i'm doing wrong?
