-
+--
+-- * Raspberry Pi BLDC/PMSM motor control design for RPi-MI-1 board *
+-- SPI connected multichannel current ADC read and averaging
+--
+-- (c) 2015 Martin Prudek <prudemar@fel.cvut.cz>
+-- Czech Technical University in Prague
+--
+-- Project supervision and original project idea
+-- idea by Pavel Pisa <pisa@cmp.felk.cvut.cz>
+--
+-- Related RPi-MI-1 hardware is designed by Petr Porazil,
+-- PiKRON Ltd <http://www.pikron.com>
+--
+-- license: GNU LGPL and GPLv3+
+--
library ieee;
use ieee.std_logic_1164.all;
entity adc_reader is
port (
- clk: in std_logic; --input clk
- adc_reset: in std_logic;
+ clk: in std_logic; --synchronous master clk
+ divided_clk : in std_logic; --divided clk - value suitable to sourcing voltage
+ adc_reset: in std_logic; --synchronous reset on rising edge
+
adc_miso: in std_logic; --spi master in slave out
- adc_channels: out std_logic_vector (35 downto 0); --consistent data of 3 channels
adc_sclk: out std_logic; --spi clk
adc_scs: out std_logic; --spi slave select
- adc_mosi: out std_logic --spi master out slave in
+ adc_mosi: out std_logic; --spi master out slave in
+
+ adc_channels: out std_logic_vector (71 downto 0); --consistent data of 3 channels
+ measur_count: out std_logic_vector(8 downto 0) --number of accumulated measurments
);
end adc_reader;
type channel_type is (ch0, ch1, ch2);
signal adc_data: std_logic_vector(11 downto 0);
- signal adc_rst_old : std_logic_vector(1 downto 0);
+ signal adc_rst_prev : std_logic;
signal adc_address: std_logic_vector(2 downto 0);
+ signal cumul_data: std_logic_vector(71 downto 0); --unconsistent data, containing different amounts of measurments
+ signal prepared_data: std_logic_vector(71 downto 0); --consistent data, waiting for clk sync to propagate to output
+ signal m_count_sig: std_logic_vector(8 downto 0); --measurments count waiting for clk to propagate to output
+ signal first_pass: std_logic;
+ signal div_clk_prev: std_logic;
begin
process
- variable data_ready : std_logic;
variable channel: channel_type;
variable reset_re: std_logic:='0';
variable reset_count: std_logic_vector (3 downto 0);
wait until (clk'event and clk='1');
--rising edge detection of reset signal
- adc_rst_old(0)<=adc_reset;
- adc_rst_old(1)<=adc_rst_old(0);
-
- if (adc_rst_old="01") then
+ adc_rst_prev<=adc_reset;
+ if (adc_rst_prev='0') and (adc_reset='1') then
reset_re:='1';
end if;
+ --rising edge detection of divided clk signal
+ div_clk_prev<=divided_clk;
+ if (divided_clk='1') and (div_clk_prev='0') then
+
case state is
when reset=>
reset_re:='0'; --clear reset flag
adc_scs<='1'; --active-low SS
adc_sclk<='0'; --lower clock
- data_ready:='0'; --mark data as unprepared
+ first_pass<='1'; --mark data as unprepared
channel:=ch0; --prepare channel0
+ adc_data<=(others=>'0'); --null working data
+ cumul_data<=(others=>'0'); --null working data
+ prepared_data<=(others=>'0'); --null the output
+ adc_channels<=(others=>'0'); --null the output
+ measur_count<=(others=>'0'); --null the count
+ m_count_sig<=(others=>'0'); --null the count
adc_address<="001"; --set its address
reset_count:="0000";
state<=rst_wait;
state<=r7;
when r7=> --7th rising edge, data ready
adc_sclk<='1';
- if (data_ready='1') then
+ if (first_pass='0') then
+ --add the current current to sum and shift the register
+ cumul_data(71 downto 0)<=
+ std_logic_vector(unsigned(cumul_data(47 downto 24))
+ +unsigned(adc_data(11 downto 0)))
+ & cumul_data(23 downto 0)
+ & cumul_data(71 downto 48);
+ end if;
+ state<=f8;
+ when f8=> --8th falling edge
+ adc_sclk<='0';
+ adc_mosi<='0'; --PD0
+ if (first_pass='0') then
case channel is
when ch0=>
- adc_channels(35 downto 24)<=adc_data(11 downto 0);
adc_address<="101"; --ch1 address
- channel:=ch1;
+ channel:=ch1; --next channel code
when ch1=>
- adc_channels(23 downto 12)<=adc_data(11 downto 0);
adc_address<="010"; --ch2 address
- channel:=ch2;
+ channel:=ch2; --next channel code
when ch2=>
- adc_channels(11 downto 0)<=adc_data(11 downto 0);
+ --data order schould be: ch2 downto ch0 downto ch1
+ prepared_data(71 downto 0)<=cumul_data(71 downto 0);
+ m_count_sig<=std_logic_vector(unsigned(m_count_sig)+1);
adc_address<="001"; --ch0 address
- channel:=ch0;
+ channel:=ch0; --next channel code
end case;
end if;
- data_ready:='1';
- state<=f8;
- when f8=> --8th falling edge
- adc_sclk<='0';
- adc_mosi<='0'; --PD0
state<=r8;
- when r8=> --8th rising edge (adc gets PD0)
+ when r8=> --8th rising edge (adc gets PD0), we propagate our results to output
adc_sclk<='1';
+ adc_channels <= prepared_data; --data
+ measur_count <= m_count_sig; --count of measurments
+ first_pass<='0'; --data in next cycle are usable
state<=f9;
when f9=> --9th falling edge busy state between conversion (we write nothing)
adc_sclk<='0';
when f10=> --10th falling edge
adc_sclk<='0';
state<=r10;
- when r10=> --10th rising edge (we read 1. bit of conversion)
+ when r10=> --10th rising edge (we read 1. bit of new conversion)
adc_sclk<='1';
adc_data(11)<=adc_miso;
state<=f11;
state<=f1;
end if;
end case;
+
+ end if;
+
end process;