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load_cell.c
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Sat, Aug 24, 20:16

load_cell.c
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#include "load_cell.h"
#include "sbcp_mdv.h"
#include <pps.h>
#include <string.h>
#include "timer.h"
#include "pindefs.h"
struct load_cell {
int torque;
lc_error_flags flags;
};
load_cell lcs[3];
load_cell * lc1 = &(lcs[0]);
load_cell * lc2 = &(lcs[1]);
load_cell * lc3 = &(lcs[2]);
/**
* Th state machine states for Magnetic encoders reception
*/
typedef enum DMA_SPI_LC_state {
DMA_SPI_LC_IDLE, ///< No reading is beeing performed.
DMA_SPI_LC_WRITING_RESET,
DMA_SPI_LC_WAITING_500us,
DMA_SPI_LC_WAITING_TO_WRITE_SETTINGS,
DMA_SPI_LC_WRITING_SETTINGS,
DMA_SPI_LC_WRITING_INSTRUCTION_2,
DMA_SPI_LC_WRITING_INSTRUCTION_3,
DMA_SPI_LC_WAITING_FOR_READOUT,
DMA_SPI_LC_READING_DEVICES, ///< We are actually reading the data from the devices
DMA_SPI_LC_DATA_READY_TO_BE_PROCESSED ///< We have finish to read the data, and we need to process it to extract atual data in the spi_main function
}DMA_SPI_LC_state;
struct DMA_SPI_LC_data {
gpio spi_cs;
gpio spi_sync;
gpio spi_mosi;
gpio spi_miso;
gpio spi_clk;
DMA_SPI_LC_state state;
};
volatile struct DMA_SPI_LC_data dma_spi_lc;
typedef struct DMA_SPI_LC_read_value{
unsigned char DATA[3];
unsigned char STATUS;
} DMA_SPI_LC_read_value;
#define CIRCULAR_BUFFER_SIZE 3
volatile unsigned char circular_buffer_ready = 0;
volatile unsigned char circular_buffer_index = 0;
volatile DMA_SPI_LC_read_value circular_buffer[CIRCULAR_BUFFER_SIZE];
unsigned char dma_spi_lc_tx_buffer[16] __attribute__((space(dma)));
volatile unsigned char dma_spi_lc_rx_buffer[16] __attribute__((space(dma)));
#define dma_spi_lc_start() do{\
gpio_clear(dma_spi_lc.spi_cs);\
}while(0)
#define dma_spi_lc_stop() do{\
gpio_set(dma_spi_lc.spi_cs);\
}while(0)
#define dma_spi_lc_write() do{\
dma_spi_lc_stop();\
dma_spi_lc_start();\
DMA4CONbits.CHEN = 1;\
DMA3CONbits.CHEN = 1;\
DMA4REQbits.FORCE = 1;\
}while(0)
void init_load_cell(load_cell * e){
e->torque = 0;
e->flags = LC_F_ONBOARD_PROCESSING_UNFINISHED;
}
void init_load_cells(){
TRISBbits.TRISB0 = 0; //RB0 in output
//Peripheral Pin Select
//PPSUnLock;
__builtin_write_OSCCONL(OSCCON & 0xbf);
PPSOutput(0, OUT_PIN_PPS_RP25); // no output on rp5
IN_FN_PPS_SDI2 = 0;// no input on rp2
IN_FN_PPS_SCK2 = 0;// no input on rp5
IN_FN_PPS_SS2 = 0;// no input on rp23
OUT_PIN_PPS_RP2 = 0;
OUT_PIN_PPS_RP5 = 0;
OUT_PIN_PPS_RP23 = 0;
OUT_PIN_PPS_RP24 = 0;
OUT_PIN_PPS_RP25 = 0;
PPSOutput(OUT_FN_PPS_SDO2, OUT_PIN_PPS_RP23); // MOSI to rp23
PPSOutput(OUT_FN_PPS_SS2, OUT_PIN_PPS_RP2); // chip select to rp2
PPSOutput(OUT_FN_PPS_SCK2, OUT_PIN_PPS_RP5); // clock out to rp5
PPSInput(PPS_SDI2, PPS_RP25);// MISO to rp25
//PPSLock;
//__builtin_write_OSCCONL(OSCCON | 0x40);
dma_spi_lc.spi_mosi = gpio_create(GPIO_PORT_C,GPIO_PIN_7,GPIO_OUTPUT);
gpio_clear(dma_spi_lc.spi_mosi);
dma_spi_lc.spi_miso = gpio_create(GPIO_PORT_C,GPIO_PIN_9,GPIO_INPUT);
gpio_set(dma_spi_lc.spi_miso);
dma_spi_lc.spi_clk = gpio_create(GPIO_PORT_B,GPIO_PIN_5,GPIO_OUTPUT);
gpio_set(dma_spi_lc.spi_clk);
dma_spi_lc.spi_sync = gpio_create(GPIO_PORT_C,GPIO_PIN_8,GPIO_OUTPUT);
gpio_set(dma_spi_lc.spi_sync);
dma_spi_lc.spi_cs = gpio_create(GPIO_PORT_B,GPIO_PIN_2,GPIO_OUTPUT);
gpio_set(dma_spi_lc.spi_cs);
dma_spi_lc.state = DMA_SPI_LC_IDLE;
/************************************
SPI2-MODULE
************************************/
SPI2STATbits.SPIEN = 0; //Disable SPI 2 module during configuration
//SPI 1 is for magentic encoders :
IEC2bits.SPI2IE = 0; //disable interrupt. This is needed because we use DMA
IFS2bits.SPI2IF = 0; //clear the interrupt flag.
IPC8bits.SPI2IP = 0b000;
SPI2CON1bits.MSTEN = 1; //enable master mode
SPI2STATbits.SPIROV = 0; // clear overflow flag
SPI2CON1bits.DISSCK = 0; //Use the clock
SPI2CON1bits.DISSDO = 0; //Disable data output. This is not needed by the application, no pin are routed
SPI2CON1bits.MODE16 = 0; //Transmit bytes. Rx buffer is in byte, but we don't care because we are transmitting an even number of byte
SPI2CON1bits.CKE = 0; //data valid on rising edge
SPI2CON1bits.CKP = 1; //clock idle state is at high level
SPI2CON1bits.SMP = 0; //0=data is sampled at middle of clock time
SPI2CON1bits.SSEN = 0; //disable chip select bit (we do this ourselves)
SPI2CON2bits.FRMEN = 0; //Frame support
//Choose a clock frequency of 625 kHz, max accepted by AS5045 is 1Mhz
//TODO: set frequency
SPI2CON1bits.SPRE = 0b000; //Select a secondary prescaler of 1:1
SPI2CON1bits.PPRE = 0b10 ; //select a primary prescaler of 64:1
IEC2bits.SPI2IE = 0; //enable interrupt.
SPI2STATbits.SPIEN = 1; //Enable SPI 2 module
/************************************
DMA3-MODULE
************************************/
IEC2bits.DMA3IE = 0;
IFS2bits.DMA3IF = 0;
IPC9bits.DMA3IP = 0b001; //low priority, but needs to be higher than DMA4IP
DMA3CONbits.CHEN = 0;
DMA3CONbits.SIZE = 1;
DMA3CONbits.DIR = 0;//read, don't send
DMA3CONbits.HALF = 0;
DMA3CONbits.NULLW = 0;
DMA3CONbits.AMODE = 0b00;// Register indirect with posincrement
DMA3CONbits.MODE = 0b00;// continuous, No Ping Pong
DMA3STA = __builtin_dmaoffset(dma_spi_lc_rx_buffer);
DMA3PAD = (volatile unsigned int) & SPI2BUF;
DMA3REQbits.IRQSEL = 0b0100001; //SPI2
DMA3CNT = 0;
IEC2bits.DMA3IE = 1;
/************************************
DMA4-MODULE
************************************/
IEC2bits.DMA4IE = 0;
IFS2bits.DMA4IF = 0;
IPC11bits.DMA4IP = 0b000; //low priority
DMA4CONbits.CHEN = 0;
DMA4CONbits.SIZE = 1; //send per byte
DMA4CONbits.DIR = 1; //send, don't read
DMA4CONbits.HALF = 0; //only one buffer
DMA4CONbits.NULLW = 0;
DMA4CONbits.AMODE = 0b00;// Register indirect with post-increment
DMA4CONbits.MODE = 0b01;// 0b01 One - shot, No Ping Pong
DMA4REQbits.IRQSEL = 0b0100001; //SPI2
DMA4CNT = 0; //number of bytes to send
DMA4STA = __builtin_dmaoffset(dma_spi_lc_tx_buffer); //transmission buffer
DMA4PAD = (volatile unsigned int) & SPI2BUF;
IEC2bits.DMA4IE = 0; //we don't need this interrupt, we use the interupt when everything is received
/************************************
CN19-MODULE
***e*********************************/
CNEN2bits.CN19IE = 1;
CNPU2bits.CN19PUE = 0;
IFS1bits.CNIF = 0;
IEC1bits.CNIE = 0; //don't enable it yet
init_load_cell(&(lcs[0]));
init_load_cell(&(lcs[1]));
init_load_cell(&(lcs[2]));
load_cell_reset();
}
inline void set_lc_torque(load_cell lc, unsigned int value, int adr) {
lc.flags = LC_F_OK;
lc.torque = value;
sbcp_me_reg(adr,LCX_VALUE).i = (long)value - (long)0x7fff;
sbcp_mark_new_low_latency_data_available();
}
#define NUMARGS(...) (sizeof((char[]){__VA_ARGS__})/sizeof(char))
#define spi_write_bytes(...) do{\
memcpy(dma_spi_lc_tx_buffer, (char [NUMARGS(__VA_ARGS__)]) {__VA_ARGS__}, NUMARGS(__VA_ARGS__)*sizeof(char));\
DMA3CNT = NUMARGS(__VA_ARGS__)-1;\
DMA4CNT = NUMARGS(__VA_ARGS__)-1;\
dma_spi_lc_write();\
}while(0)
#define spi_led_on() spi_write_bytes(0x28,0x31)
#define spi_led_off() spi_write_bytes(0x28,0x30)
#define spi_led_blink() spi_write_bytes(0x28,0x30|BLINK)
#define spi_settings 0b00001000,0b00011000,0b00100000,0b00000001, /*write to mode register (24 bits)*/\
0b00010000,0b00000000,0b00000111,0b11010111, /*write to configuration register (24 bits) */ \
0b00101000,0b01000000 /* write to GPOCON register (8 bits) close the Bridge power-down switch*/
int lc_error_count=0;
int reset_counter;
volatile short start_reading = 0;
void load_cell_process(){
int v;
int index;
DMA_SPI_LC_read_value value;
unsigned short p;
if(start_reading){
start_reading=0;
dma_spi_lc.state = DMA_SPI_LC_READING_DEVICES;
spi_write_bytes(0x58,0x00,0x00,0x00,0x00); // read 4 bytes
}
if(circular_buffer_ready){
for(index = 0; index<CIRCULAR_BUFFER_SIZE; index++){
IEC2bits.DMA3IE = 0;//disable writing to circular buffer while reading from it, without losing interrupts.
value = circular_buffer[index]; //copy to remove race conditions with interupt
IEC2bits.DMA3IE = 1;
// step 1: check parity
v = value.DATA[0] ^ value.DATA[1] ^ value.DATA[2];
v = (v ^ v>>4) & 0x0f;
p = (0x6996 >> v) & 1; //Look-up table
if(value.DATA[0] == 0 && value.DATA[1] == 0 && value.DATA[2] == 0 && value.STATUS == 0){//while strictly speaking, this is a correct packet, it is more likely something is going wrong
lc_error_count++;
}
if(p != (value.STATUS & 0b00010000)>>4){
lc_error_count++;
}else if(value.STATUS & 0b11100000){ //RDY, ERR, NOREF
lc_error_count++;
}else {
switch(value.STATUS & 0b00001111){
case 0:
set_lc_torque(lcs[0], (value.DATA[0]<<8) | (value.DATA[1]),MDV_LC_AXIS_1);
break;
case 1:
set_lc_torque(lcs[1], (value.DATA[0]<<8) | (value.DATA[1]),MDV_LC_AXIS_2);
break;
case 2:
set_lc_torque(lcs[2], (value.DATA[0]<<8) | (value.DATA[1]),MDV_LC_AXIS_3);
break;
default:
lc_error_count++;
}
}
}
if(lc_error_count>100){
if(dma_spi_lc.state == DMA_SPI_LC_WAITING_FOR_READOUT
|| dma_spi_lc.state == DMA_SPI_LC_READING_DEVICES){
lc_error_count=0;
load_cell_reset();
}
}
}
}
void load_cell_reset(){
IEC1bits.CNIE = 0;
circular_buffer_ready = 0;
reset_counter = 0;
start_reading=0;
dma_spi_lc.state = DMA_SPI_LC_WRITING_RESET;
spi_write_bytes(0xff,0xff,0xff,0xff,0xff);
}
void load_cell_start_reading(){
if(dma_spi_lc.state == DMA_SPI_LC_IDLE){
//start reading
dma_spi_lc.state = DMA_SPI_LC_WAITING_FOR_READOUT;
IEC1bits.CNIE = 1;
LATBbits.LATB0 = 1;
}
if(dma_spi_lc.state == DMA_SPI_LC_WAITING_TO_WRITE_SETTINGS){
if(reset_counter == 0){ //you need to wait at least 500us to start writing the settings. We wait for an additional 1ms so we are sure we waited long enough.
reset_counter++;
}else{
dma_spi_lc.state = DMA_SPI_LC_WRITING_SETTINGS;
spi_write_bytes(spi_settings);
}
}
}
/*******************************************************************************
*
* Interrupt
*
******************************************************************************/
/**
* Interrupt when the DMA finished reading all the bytes
*/
void __attribute__((__interrupt__ , no_auto_psv)) _DMA3Interrupt(){
switch(dma_spi_lc.state){
case DMA_SPI_LC_WRITING_RESET:
dma_spi_lc.state = DMA_SPI_LC_WAITING_TO_WRITE_SETTINGS;
break;
case DMA_SPI_LC_WRITING_SETTINGS:
spi_led_on();
dma_spi_lc.state = DMA_SPI_LC_WRITING_INSTRUCTION_2; //todo,
break;
case DMA_SPI_LC_WRITING_INSTRUCTION_2:
dma_spi_lc.state = DMA_SPI_LC_IDLE; //todo,
break;
case DMA_SPI_LC_WRITING_INSTRUCTION_3:
dma_spi_lc.state = DMA_SPI_LC_IDLE; //todo,
break;
case DMA_SPI_LC_READING_DEVICES:
dma_spi_lc.state = DMA_SPI_LC_WAITING_FOR_READOUT;
circular_buffer[circular_buffer_index].DATA[0] = dma_spi_lc_rx_buffer[1];
circular_buffer[circular_buffer_index].DATA[1] = dma_spi_lc_rx_buffer[2];
circular_buffer[circular_buffer_index].DATA[2] = dma_spi_lc_rx_buffer[3];
circular_buffer[circular_buffer_index].STATUS = dma_spi_lc_rx_buffer[4];
circular_buffer_index++;
if(circular_buffer_index >= CIRCULAR_BUFFER_SIZE){
circular_buffer_index = 0;
circular_buffer_ready = 1;
}
IEC1bits.CNIE = 1;// re-enable the read interrupt after communication is done
LATBbits.LATB0 = 0;
break;
default:
dma_spi_lc.state = DMA_SPI_LC_IDLE; //todo,
break;
}
//gpio_set(dma_spi_lc.spi_mosi);//Idle high
IFS2bits.DMA3IF = 0;//clear the interrupt flag
}
/**
* Interrupt when the DMA finished its writing of all the bytes
*/
void __attribute__((__interrupt__ , no_auto_psv)) _DMA4Interrupt(){
//clear the interruption flag
//DMA4CONbits.CHEN = 0;
//dma_spi_lc.state = DMA_SPI_LC_IDLE;
//dma_spi_lc_stop();
IFS2bits.DMA4IF = 0;
}
/**
* Interrupt when the SPI 2 finished writing and reading a byte
*/
void __attribute__((__interrupt__, no_auto_psv)) _SPI2Interrupt(void)
{
//SPI2STATbits.SPIROV = 0;
IFS2bits.SPI2IF = 0; // Clear the SPI1 Interrupt Flag
//SPI1BUF=0; // send next byte, not necassary if NULLW set
}
void __attribute__((__interrupt__ , no_auto_psv)) _CNInterrupt(){
if(dma_spi_lc.state == DMA_SPI_LC_WAITING_FOR_READOUT){
if(gpio_read(dma_spi_lc.spi_miso) == 0){
IEC1bits.CNIE = 0;// disable this interrupt during communication
start_reading = 1;
}
}
IFS1bits.CNIF = 0;
}
int lc_get_torque(load_cell * e){
return e->torque;
}
lc_error_flags lc_get_error(load_cell * e){
return e->flags;
}
void lc_load_persistent_sbcp_settings(){
}

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