Currently I am trying to create a program that will output an analog signal to an LED using the LTC1661 chip with the PIC18F97J60.
The dac ltc1661 chip is connected to my board with the ports:
RC3 for SCK1
RC5 for SDO1
with the data pin being connected to my 8bit SPIBUF buffer.
Here is my code, its outputting to the led but I can't seem to make the led gradually increase in bright ness, its just a sudden on and off.
Any help would be appreciated.
#include "amt.h"
#include <p18f97j60.h>
int main(void) {
TRISCbits.RC3 = 0;
TRISCbits.RC5 = 0;
TRISCbits.RC7 = 0;
SSP1CON1 = 0b00100010; // Enable SPI, CKP=0, Master, Fosc/64
SSP1STATbits.CKE = 1; // CKE=1, (rising edge for shift register)
char temp;
while(1) {
//SSP1BUF = 0x00;
PORTCbits.RC7 = 0;
SSP1BUF = 0x98;
while(PIR1bits.SSPIF==0);
SSP1BUF = 0x00;
while(PIR1bits.SSPIF==0);
PORTCbits.RC7 = 1;
PORTCbits.RC7 = 0;
SSP1BUF = 0x98;
while(PIR1bits.SSPIF==0);
SSP1BUF = 0x04;
while(PIR1bits.SSPIF==0);
PORTCbits.RC7 = 1;
}
}
Related
I am using a PIC 18F46K22 in SPI master mode to communicate with a Waveshare 1.54" ePaper Module. The FOSC frequency is 8Mhz internal and SPI configuration is FOSC/4. So when I check the output on logic-analyzer some output bits are differ from expected. And there is some deviation in SCL.
#include <xc.h>
#include "config.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "main.h"
//#define _XTAL_FREQ 8000000
#define SPI1_DUMMY_DATA 0x0
#define SPI_RX_IN_PROGRESS 0x0
#define MY_BUFFER_SIZE 25
extern UBYTE EPD_Init(const unsigned char* lut);
unsigned char myWriteBuffer[100]="Hi I'm master..";
uint8_t myReadBuffer[100];
uint8_t total;
uint8_t temp;
uint8_t my_data = 0x58;
void UART_Init(void)
{
//69
SPBRG2 = 69;
TXSTA2bits.BRGH = 1;
BAUDCON2bits.BRG16 = 1; // Divisor at 8 bit
TRISDbits.TRISD6 = 0;
TRISDbits.TRISD7 = 1;
RCSTA2bits.SPEN = 1; // Enable serial port
TXSTA2bits.SYNC = 0; // Async operation
TXSTA2bits.TX9 = 0; // No tx of 9th bit
RCSTA2bits.RX9 = 0; // No rx of 9th bit
TXSTA2bits.TXEN = 1; // Enable transmitter
RCSTA2bits.CREN = 1; // Enable receiver
}
void UART_Putch(unsigned char bt)
{
while (!PIR3bits.TX2IF); // hold the program till TX buffer is free
TXREG2 = bt; //Load the transmitter buffer with the received value
}
void UART_Print(unsigned const char *ptr)
{
while (*ptr != 0)
{
UART_Putch(*ptr++);
}
}
unsigned char UART_getch() {
unsigned char temp;
if (RCSTA2bits.OERR) // check for Error
{
RCSTA2bits.CREN = 0; //If error -> Reset
//__delay_ms(10);
RCSTA2bits.CREN = 1; //If error -> Reset
}
while (!PIR3bits.RC2IF); // hold the program till RX buffer is free
temp = RCREG2;
return temp; //receive the value and send it to main function
}
void main()
{
ANSELA = 0;
ANSELB = 0;
ANSELC = 0;
ANSELD = 0;
TRISBbits.TRISB0 = 0; //RST Pin OUTPUT
TRISBbits.TRISB1 = 0; //DC Pin OUTPUT
TRISBbits.TRISB2 = 0; //CS Pin OUTPUT
TRISBbits.RB3 = 1; //BUSY Pin INPUT
// int i;
TRISD =0;/* PORT initialize as output */
EPD_RST_PIN = 0;
EPD_DC_PIN = 0;
//OSCCON = 0x72; /* Use internal osc. frequency 16 MHz */
OSCCONbits.SCS = 0b10; //Frequency & PLL SETUP
OSCCONbits.IRCF = 0b110; //8 MHz
while (!OSCCONbits.HFIOFS);
OSCTUNEbits.PLLEN = 0; //PLL disable
UART_Init();
SPI_Init_Master(); /* Initialize SPI communication as a master */
if(EPD_Init(lut_full_update) != 0) {
UART_Print("e-Paper init failed\r\n");
while(1);
}
UART_Print("e-Paper init\r\n");
for(uint8_t i = 0; i < 10; i++){
__delay_ms(10);
}
EPD_Clear();
UART_Print("e-Paper cleared\r\n");
for(uint8_t i = 0; i < 10; i++){
__delay_ms(50);
}
while(1)
{
// total = 0;
// //do
// //{
// LATAbits.LATA5=0;
// //total = SPI1_Exchange8bitBuffer(SPI1_DUMMY_DATA, MY_BUFFER_SIZE, &myReadBuffer[total]);
// total = SPI1_Exchange8bit(my_data);
//
// LATAbits.LATA5=1;
// __delay_ms(500);
// __delay_ms(500);
// // Do something else...
//
// //} while(total < MY_BUFFER_SIZE);
// //while(1);
//
// EPD_Clear();
//
// __delay_ms(500);
}
}
void SPI_Init_Master()
{
/* PORT definition for SPI pins*/
TRISCbits.TRISC4 = 1; /* RB0 as input(SDI) */
TRISCbits.TRISC3 = 0; /* RB1 as output(SCK) */
// TRISBbits.TRISB2 = 0; /* RA5 as a output(SS') */
TRISCbits.TRISC5 = 0; /* RC7 as output(SDO) */
/* To initialize SPI Communication configure following Register*/
EPD_CS_PIN = 1;
SSP1STAT=0x00; /* Data change on rising edge of clk , BF=0*/
SSP1CON1=0x20; /* Slave mode,Serial enable, idle state high for clk */
PIR1bits.SSP1IF=0;
/* Disable the ADC channel which are on for multiplexed pin
when used as an input */
ADCON0=0; /* This is for de-multiplexed the SCL
and SDI from analog pins*/
ADCON1=0x0F; /* This makes all pins as digital I/O */
}
uint8_t SPI1_Exchange8bit(uint8_t data)
{
// Clear the Write Collision flag, to allow writing
SSP1CON1bits.WCOL = 0;
SSP1BUF = data;
while(SSP1STATbits.BF == SPI_RX_IN_PROGRESS)
{
}
return (SSP1BUF);
}
uint8_t SPI1_Exchange8bitBuffer(uint8_t *dataIn, uint8_t bufLen, uint8_t *dataOut)
{
uint8_t bytesWritten = 0;
if(bufLen != 0)
{
if(dataIn != NULL)
{
while(bytesWritten < bufLen)
{
if(dataOut == NULL)
{
SPI1_Exchange8bit(dataIn[bytesWritten]);
}
else
{
dataOut[bytesWritten] = SPI1_Exchange8bit(dataIn[bytesWritten]);
}
bytesWritten++;
}
}
else
{
if(dataOut != NULL)
{
while(bytesWritten < bufLen )
{
temp = SPI1_Exchange8bit(SPI1_DUMMY_DATA);
if(temp!=SPI1_DUMMY_DATA)
{
UART_Putch(temp); //uart print
dataOut[bytesWritten] = temp;
bytesWritten++;
}
__delay_ms(5);
}
}
}
}
return bytesWritten;
}
Compare your logic analyser SCK and MOSI timing with that specified for the part at https://www.waveshare.com/wiki/1.54inch_e-Paper_Module:
Note that the MOSI (SDIN) state must be stable on the rising edge of SCK (SCLK). In your case the MOSI transitions are synchronous with the rising edge, and you have a clock transition before the MOSI has the correct D7=0 state. SPI timing is defined by both clock polarity and clock phase - giving four possible clock modes. Compare the Waveshare timing diagram with the 18F46K22 datasheet:
The Waveshare diagram suggests that either CKP=1/CKE=0, or CKP=0/CKE=1 may be used, you have:
SSP1STAT=0x00 ;
SSP1CON1=0x20 ;
Which is CKP=0/CKE=0 (which correlates with your logic analyser trace).
You need on of either:
SSP1STAT=0x20 ; // CKE=1
SSP1CON1=0x20 ; // CKP=0
or
SSP1STAT=0x00 ; // CKE=0
SSP1CON1=0x30 ; // CKP=1
Since idle state (controlled by CKP) of SCK is a don't-care, I suggest leaving that as-is and using the first suggestion - that seems more intuitive somehow.
Note also that your logic analyser must also be set to the same phase/polarity clock mode in order for its presentation of the data to be correct.
I've attached an image showing my oscilloscope readout which is from the code below. Context: I have a Pi and a PIC which need to communicate through UART connection. I've implemented my own flow control which can be seen in the image attached [RTS = Yellow Trace, CTS = Blue Trace, Rx = Green Trace]. The code runs through and is caught in the final switch case statement which turns on an LED. But when i debug the code, no values (well the only value which is read is zero) are read in. At first i thought that i'd configured my PIC clock wrong (which is used to derive the baud rate), but i don't think this is the case. Second i through the FIFO buffer was full of zeros only and considering that i'm sending only four packets of information to the PIC, and my FIFO is 4 registers deep that this was the reason why non of the information was appearing. So i executed a code which removes the dummy bytes but this did not work.
All that is received:
0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0><0> etc
I got the right settings selected: baud rate: 9600 data bits: 8 parity: none stop bits: 1
If anyone is willing to spend some time looking at my code, can you see any obvious errors?
https://i.stack.imgur.com/aQoAL.jpg
Minimum Reproducible Example
# include <xc.h>
# include <math.h>
# include <stdio.h>
# include <stdio.h>
//Configuration Bits
#pragma config FNOSC = FRCPLL // Internal Fast RC Oscillator (8MHz)
#pragma config FPLLIDIV = DIV_2 // Divide FRC before PLL (Now 4MHz)
#pragma config FPLLMUL = MUL_20 // PLL Multiply (Now 80MHz)
#pragma config FPLLODIV = DIV_2 // Divide After PLL (Now 40MHz)
#pragma config FPBDIV = DIV_1 // Pheripheral Bus Clock (At 40KHz)
#pragma config FWDTEN = OFF // Watchdog Timer Disabled
#pragma config ICESEL = ICS_PGx2 // ICE/ICD Comm Channel Select
#pragma config JTAGEN = OFF // Disable JTAG
#pragma config FSOSCEN = OFF // Disable Secondary Oscillator
//*****************************UART Functions***********************************
void UART_Config (void) // Baude Rate of 9600, 8-Bit Data , 1 Stop Bit
{
U1MODEbits.BRGH = 0;
U1BRG = 259; //U1BRG = (40M/ (16 * 9.6k))) - 1
U1MODEbits.SIDL = 0; // Continue operation in SLEEP mode
U1MODEbits.IREN = 0; // IrDA is disabled
U1MODEbits.RTSMD = 0; // U1RTS pin is in Flow Control mode
U1MODEbits.UEN = 0b00; // U1TX, U1RX are enabled
U1MODEbits.WAKE = 1; // Wake-up enabled
U1MODEbits.LPBACK = 0; // Loopback mode is disabled
U1MODEbits.RXINV = 0; // U1RX IDLE state is '1'
U1MODEbits.PDSEL = 0b00; // 8-bit data, no parity
U1MODEbits.STSEL = 0; // 1 stop bit
U1STAbits.UTXINV = 0; // U1TX IDLE state is '1'
U1MODEbits.ON = 1; // UART1 is enabled
U1STAbits.URXEN = 1; // UART1 receiver is enabled
U1STAbits.UTXEN = 1; // UART1 transmitter is enabled
}
void Send_UART_Data(unsigned int c) // PIC Sending Data for Pi to Read
{
U1STAbits.UTXEN = 1; // Make sure transmitter is enabled
// while(CTS) // Optional CTS (Clear to Send) use
while(U1STAbits.UTXBF); // Wait while buffer is full
U1TXREG = c; // Transmit character
}
int Read_UART_Data (void) // PIC Reading Sent Data from Pi
{
int c;
while(!U1STAbits.URXDA) // Wait for information to be received
c = (int)U1RXREG; // Convert Character to Value
return c;
}
ADC_To_UART (unsigned int ADC)
{
unsigned int temp_A = 0x00;
unsigned int temp_B = 0x00;
// Splitting a 10 Bit Word Into 2 Bytes [aa aaaa aabb]
// Start Bit = 1 , Stop Bit = 0
// UART Transmission Pattern [1 aaaa aaaa 0 0000 00 bb]
temp_A = ADC >> 2; // MSB(8 Bits) ~ ADC[9:2] [aaaa aaaa]
temp_B = ADC & 0x003; // LSB(2 Bits) ~ ADC[1:0] [0000 00bb]
Send_UART_Data(temp_A);
Send_UART_Data(temp_B);
}
[enter image description here][1]
//*********************Enumerated Variable Declaration**************************
//Program Flow Control
enum Comm_State {Phase1A, Phase1B, Phase1C, Phase1D, Phase1E, Phase2A, Phase2B, Phase2C, Phase2D, Phase2E, Phase2F, Phase2G};
//******************************************************************************
//********************************MAIN******************************************
int main( )
{
//***************************Configuration**********************************
// I/O Definitions
#define UART_TRIS_RX TRISBbits.TRISB13 // UART RX - Reciever Pin (PPS)
#define UART_TRIS_TX TRISBbits.TRISB15 // UART TX - Transmission Pin (PPS)
#define UART_TRIS_CTS_PIC TRISAbits.TRISA4 // UART CTS_1 - Clear to Send - Output [CTS PIC]
#define UART_TRIS_RTS_PIC TRISBbits.TRISB4 // UART RTS_1 - Ready to Send - Output [RTS PIC]
#define UART_TRIS_CTS_PI TRISAbits.TRISA3 // UART CTS_2 - Clear to Send - Input [CTS PI]
#define UART_TRIS_RTS_PI TRISAbits.TRISA2 // UART_RTS_2 - Ready to Send - Input [RTS PI]
#define SPI_TRIS_SCK TRISBbits.TRISB14 // SPI SCK - Serial Clock Pin (PPS?)
#define SPI_TRIS_SDO TRISBbits.TRISB6 // SPI SDO - Serial Data Out Pin (PPS?)
#define SPI_TRIS_CS_1 TRISBbits.TRISB8 // SPI CS1 - DAC 2 Chip Select Pin (PPS?)
#define SPI_TRIS_CS_2 TRISBbits.TRISB7 // SPI CS2 - DAC 1 Chip Select Pin (PPS?)
#define AN4_TRIS TRISBbits.TRISB2 // Analogue Read 3
#define AN3_TRIS TRISBbits.TRISB1 // Analogue Read 2
#define AN2_TRIS TRISBbits.TRISB0 // Analogue Read 1
#define V_REF_TRIS_Plus TRISAbits.TRISA0 // Analogue V_REF(+) (Forms VRange)
#define V_REF_TRIS_Minus TRISAbits.TRISA1 // Analogue V_REF(-) (Forms VRange)
#define Reg_Enable_TRIS_D TRISBbits.TRISB9 // Regulator Digital Control (Output)
#define Reg_Enable_TRIS_M TRISBbits.TRISB12 // Regulator Button (Input)
// Port Input/Output Configuration [TRISB]
TRISB = 0x1004; // All of PortB set as Outputs Except for RB12 (Reg Enable) and RB2 (Input -> Analogue Input (Voltage)) (Port B) = (0000 ... 0100)
TRISA = 0x0003; // Set up A0 [Pin 2] and A1 [Pin 3] as V_REF(+) and V_REF(-) Respectively (Port B) = (0000 ... 0011)
UART_TRIS_RX = 1; // UART Receiver ~ Input
UART_TRIS_TX = 0; // UART Transmission ~ Output
UART_TRIS_CTS_PIC = 0; // UART "CTS_PIC" ~ Output
UART_TRIS_RTS_PIC = 0; // UART "RTS_PIC" ~ Output
UART_TRIS_CTS_PI = 1; // UART "CTS_PI" ~ Input
UART_TRIS_RTS_PI = 1; // UART "RTS_PI" ~ Input
SPI_TRIS_SCK = 0; // SPI Clock ~ Output
SPI_TRIS_SDO = 0; // SPI Data Output ~ Output
SPI_TRIS_CS_1 = 0; // SPI Chip Select 1 ~ Output
SPI_TRIS_CS_2 = 0; // SPI Chip Select 2 ~ Output
AN4_TRIS = 1; // Analogue Read In ~ Input
AN3_TRIS = 1; // Analogue Read In ~ Input
AN2_TRIS = 1; // Analogue Read In ~ Input
V_REF_TRIS_Plus = 1; // V_Ref(+) ~ Input
V_REF_TRIS_Minus = 1; // V_Ref(-) Differential Measurements ~ Input
Reg_Enable_TRIS_D = 0; // Regulator Digital Control (Output)
Reg_Enable_TRIS_M = 1; // Regulator Switch Control (Input)
// Peripheral Pin Select Configurations
U1RXR = 0x0011; // UART PPS Mapping
RPB15R = 0x0001; // UART PPS Mapping
// Analogue Pin Configurations
ANSELB = 0x0028; // RB0 RB1 RB2 = AN2 AN3 AN4 [0001 1100]
ANSELA = 0x0000; // Set all Analogue Inputs of Port A Off
//**************Sub-System Configurations*********************************//
// UART Control Configure
UART_Config(); //UART Control Configure
#define PIC_CTS LATAbits.LATA4 // Output Set Definition [1]
#define PIC_RTS LATBbits.LATB4 // Output Set Definition [2]
#define PI_CTS PORTAbits.RA3 // Input Read Definition [2]
#define PI_RTS PORTAbits.RA2 // Input Read Definition [1]
// Analogue Control Configure
ADC_Config(); // Configure ADC
AD1CON1SET = 0x8000; // Enable ADC
//***************Variable Declarations************************************//
enum Comm_State Communication_State = Phase1A; //Controller Variable
unsigned int temp1 = 0;
unsigned int Comms_Flag_1 = 0;
unsigned int ConFlag = 1;
unsigned int i = 1;
unsigned int UART_ADC_CV_1 = 0;
unsigned int UART_ADC_CV_2 = 0;
unsigned int ADC_CV = 0;
unsigned int UART_ADC_CC_1 = 0;
unsigned int UART_ADC_CC_2 = 0;
unsigned int ADC_CC = 0;
unsigned int DAC_CV = 0;
float I_CC = 0;
float V_CV = 0;
//***************Program Flow - Switch State Controlled*******************//
while(1)
{
switch (Communication_State)
{
case Phase1A: // Check For Pi Ready to Send CV ADC Value
//PIC_CTS = 0;
//Pic_Refresh();
PIC_RTS = 0;
PIC_CTS = 1;
if (PI_RTS == 1)
{
PIC_CTS = 0;
Communication_State = Phase1B;
}
break;
case Phase1B: // Receive CV ~ 12 Bit ADC Value [Two Data Packets with 0.01 Second Delay]
ConFlag = 1;
i = 1;
while (ConFlag == 1)
{
if (PI_RTS == 1 && i == 1)
{
UART_ADC_CV_1 = Read_UART_Data(); //Data Packet 1 Returned - MSB(Bit 15) to Bit 8
i++;
}
else if (PI_RTS == 1 && i == 2)
{
UART_ADC_CV_2 = Read_UART_Data(); //Data Packet 2 Returned - Bit (7)) to LSB(Bit 0)
}
else
{
ConFlag = 0;
}
}
Communication_State = Phase1C;
break;
case Phase1C: // Check for CC Value
delay(); //Ensure that Pi_RTS has gone low after sending last Transmission (Prevents Code from Running Away)
PIC_CTS = 1;
if (PI_RTS == 1)
{
PIC_CTS = 0;
Communication_State = Phase1D;
}
break;
case Phase1D: // Receive CC Value [Two Data Packets with 0.01 Second Delay]
ConFlag = 1;
i = 1;
while (ConFlag == 1)
{
if (PI_RTS == 1 && i == 1)
{
UART_ADC_CC_1 = Read_UART_Data(); //Data Packet 1 Returned - MSB(Bit 15) to Bit 8
i++;
}
else if (PI_RTS == 1 && i == 2)
{
UART_ADC_CC_2 = Read_UART_Data(); //Data Packet 2 Returned - Bit (7)) to LSB(Bit 0)
}
else
{
ConFlag = 0;
}
}
Communication_State = Phase1E;
break;
case Phase1E: // Calculations
// CV Calculations
temp1 = UART_ADC_CV_1 << 8;
ADC_CV = temp1 + UART_ADC_CV_2;
V_CV = ADC_CV * (4.096/4096);
DAC_CV = ADC_CV | 4096;
Comms_Flag_1 = SPI_Transfer(DAC_CV ,1); // Data Transmitted to DAC 1, Upon Transmission LED Turns Green (No Acknowledgement)
// CC Calculations
temp1 = UART_ADC_CC_1 << 8;
ADC_CC = temp1 + UART_ADC_CC_2;
I_CC = ADC_CC * (4.096/4096);
Communication_State = Phase2A;
break;
case Phase2A:
while(1)
{
LATBbits.LATB5 = 1;
}
break;
}
}
return 1;
}
In Read_UART_Data, you have:
while(!U1STAbits.URXDA)
c = (int)U1RXREG;
I think you're missing a semicolon because this is actually:
while (!U1STAbits.URXDA)
c = (int) U1RXREG;
This means that c is set only when the UART receiver is not ready.
What I think you meant is:
while (!U1STAbits.URXDA);
c = (int) U1RXREG;
I'm able to receive with the following code, but unfortunately, nothing is sent back. What am I doing wrong?
#include <pic18f25k80.h>
#include "config.h"
#include <usart.h>
int i = 0;
unsigned char MessageBuffer[200];
void main() {
OSCCONbits.IRCF = 0b110; // 8MHz
TRISB6 = 0; // TX set as output
TRISB7 = 0; // RX set as output
// Clear TX interrupt
// Set RX interrupt
// 8-bit Asynch. mode
// BRGH = 1 = high baud mode
// 51 = ((8MHz/baud)/16)-1 with baud = 9600
Open2USART(USART_TX_INT_OFF & USART_RX_INT_ON & USART_ASYNCH_MODE
& USART_EIGHT_BIT & USART_BRGH_HIGH, 51 );
RC2IF = 0; // reset RX2 flag
RC2IP = 0; // not high priority
RC2IE = 1; // Eneble RX2 interrupt
INTCONbits.PEIE = 1; // enable peripheral interrupts
INTCONbits.GIE = 1; // enable interrupts
RCSTA2bits.SPEN = 1; // enable USART
while(1){
}
}
void interrupt ISR () {
if(PIR3bits.RC2IF == 1) {
if(i<200) { // buffer size
MessageBuffer[i] = Read2USART(); // read byte from RX reg
if (MessageBuffer[i] == 0x0D) { // check for return key
puts2USART(MessageBuffer);
for(;i>0;i--)
MessageBuffer[i] = 0x00; // clear array
i=0;
return;
}
i++;
RC2IF = 0; // clear RX flag
} else {
puts2USART(MessageBuffer);
for(;i>0;i--)
MessageBuffer[i] = 0x00; // clear array
i = 0;
return;
}
}
}
I'm transmitting the 0x41 hex code, I checked with the scope and see that is is being received. And according to the code I have, an echo of the received data should be sent back. When I check the TX pin, nothing is happening.
Add USART_CONT_RX to Open2USART to enable continuous receive.
Also, it's a good idea to do the minimum necessary in the interrupt service routine. Consider something like:
void interrupt ISR () {
char data;
if(PIR3bits.RC2IF == 1) {
data = Read2USART(); // always read byte from RX reg (clears RC2IF)
if(i<200) { // buffer size
MessageBuffer[i] = data; // read byte from RX reg
i++;
}
else{
// flag buffer full error
}
}
}
and doing the rest of what you are doing in the while(1) loop.
Good afternoon,
I've configured my RX interrupt using the following simple function.
char c;
void __attribute__((interrupt, no_auto_psv)) _U1RXInterrupt( void )
{
IFS0bits.U1RXIF = 0; // Clear RX Interrupt flag
c = U1RXREG;
}
The problem is, UART transmits fine, but the interrupt service routine is never entered when it gets sent a character. I can trace with a scope that the character is actually sent without issues, but the interrupt does not get triggered.
The device used for communication is TTL-232R-3v3. The device is running at 3.3V
The actual model number of the dspic33 is p33FJ128MC802
The programming environment is Mplab 8 and the compiled is XC16
Is there a missing setting to perhaps enable the interrupt? What could be missing?
Thanks,
Here is the UART initialization code.
U1MODEbits.UARTEN = 0; // Bit15 TX, RX DISABLED, ENABLE at end of func
U1MODEbits.USIDL = 0; // Bit13 Continue in Idle
U1MODEbits.IREN = 0; // Bit12 No IR translation
U1MODEbits.RTSMD = 0; // Bit11 Simplex Mode
U1MODEbits.UEN = 0; // Bits8,9 TX,RX enabled, CTS,RTS not
U1MODEbits.WAKE = 0; // Bit7 No Wake up (since we don't sleep here)
U1MODEbits.LPBACK = 0; // Bit6 No Loop Back
U1MODEbits.ABAUD = 0; // Bit5 No Autobaud (would require sending '55')
U1MODEbits.URXINV = 0; // Bit4 IdleState = 1 (for dsPIC)
U1MODEbits.BRGH = 0; // Bit3 16 clocks per bit period
U1MODEbits.PDSEL = 0; // Bits1,2 8bit, No Parity
U1MODEbits.STSEL = 0; // Bit0 One Stop Bit
// U1BRG = (Fcy / (16 * BaudRate)) - 1
// U1BRG = (36850000 / (16 * 9600)) - 1
// U1BRG = 238.908854 //Round to 239
U1BRG = 239;
U1STAbits.UTXISEL1 = 0; //Bit15 Int when Char is transferred (1/2 config!)
U1STAbits.UTXINV = 0; //Bit14 N/A, IRDA config
U1STAbits.UTXISEL0 = 0; //Bit13 Other half of Bit15
U1STAbits.UTXBRK = 0; //Bit11 Disabled
U1STAbits.UTXEN = 0; //Bit10 TX pins controlled by periph
U1STAbits.UTXBF = 0; //Bit9 *Read Only Bit*
U1STAbits.TRMT = 0; //Bit8 *Read Only bit*
U1STAbits.URXISEL = 0; //Bits6,7 Int. on character recieved
U1STAbits.ADDEN = 0; //Bit5 Address Detect Disabled
U1STAbits.RIDLE = 0; //Bit4 *Read Only Bit*
U1STAbits.PERR = 0; //Bit3 *Read Only Bit*
U1STAbits.FERR = 0; //Bit2 *Read Only Bit*
U1STAbits.OERR = 0; //Bit1 *Read Only Bit*
U1STAbits.URXDA = 0; //Bit0 *Read Only Bit*
RPINR18bits.U1RXR = 0b00010;//7; //RX is Pin RP2
RPOR1bits.RP3R = 0b00011; //TX is pin RP3
U1MODEbits.UARTEN = 1; // And turn the peripheral on
U1STAbits.UTXEN = 1;
Check if the pin has additional functionality. Typically this is AD (analog pin). Make sure you turn off all analog, via the ADP or ANSEL registers (type and number varies depending on exact chip) E.g. I have this routine (I use both 33F and 33E and a high and low pincount one of both, hence the ifdefs)
void analogoff(void){
#if defined(__dsPIC33F__)
ADPCFG =0xFFFF;
AD1PCFGH=0xFFFF;
AD1PCFGL=0xFFFF;
#endif
#if defined(__dsPIC33E__)
#if !defined(__dsPIC33EP256MU806__)
ANSELA=0;
#endif
ANSELB=0;
ANSELC=0;
ANSELD=0;
ANSELE=0;
ANSELG=0;
#endif
}
Also, make absolutely sure the oscillator and thus the part's speed is correct, though if TX has the correct baudrate (scope!) that is probably ok.
My uart1 init:
U1BRG = brgval;
U1MODE = 0x8000; // Reset UART to 8-n-1, alt pins, and enable lowspeed (=bit 3)
U1MODEbits.USIDL =0; // disable module when device is idle.
U1MODEbits.IREN =0; // IRDA disable
U1MODEbits.RTSMD =0; // flow control mode (1= simplex mode)
U1MODEbits.UEN =0; // RTS en CTS controlled by PORTlatches
U1MODEbits.WAKE =0; // no wakeup enabled;
U1MODEbits.LPBACK=0; // loopback disabled
U1MODEbits.ABAUD =0; // no autobaud
#if !defined(__PIC24F__)
U1MODEbits.URXINV =0; // RXINV inversion RX. (0= idle = '1')
#endif
U1MODEbits.BRGH =1; // high speed.
U1MODEbits.PDSEL =0; // 8 bit no parity
U1MODEbits.STSEL =0; // 1 stopbit.
U1STA = 0x0440;
U1STAbits.URXISEL0=0;// Reset status register and enable TX & RX.
U1STAbits.URXISEL1=0; // rx interrupt on a char.
_U1RXIF=0; // Clear UART RX Interrupt Flag
_U1RXIE = 1; // Interruption active pour la reception
_U1RXIP=2;
_U1TXIP=2;
_U1TXIF=0;
_U1TXIE=0; // only enabled when actually sending
U1MODEbits.UARTEN=1;
How can I send the string "MY STRING" from a master pic to a slave?
I'm using MicroC RS-485 library example:
http://www.mikroe.com/download/eng/documents/compilers/mikroc/pro/pic/help/rs-485_library.htm
Im trying to send string from master to slave: and seting dat[7] = "my string"; expecting dat[7] on slave with my string but im geting empty value...
Original code in the link bottom.
Master
char dat[10]; // buffer for receving/sending messages
char i,j;
sbit rs485_rxtx_pin at RC2_bit; // set transcieve pin
sbit rs485_rxtx_pin_direction at TRISC2_bit; // set transcieve pin direction
// Interrupt routine
void interrupt() {
RS485Master_Receive(dat);
}
void main(){
long cnt = 0;
ANSEL = 0; // Configure AN pins as digital I/O
ANSELH = 0;
C1ON_bit = 0; // Disable comparators
C2ON_bit = 0;
PORTB = 0;
PORTD = 0;
TRISB = 0;
TRISD = 0;
UART1_Init(9600); // initialize UART1 module
Delay_ms(100);
RS485Master_Init(); // initialize MCU as Master
dat[0] = 0xAA;
dat[1] = 0xF0;
dat[2] = 0x0F;
dat[4] = 0; // ensure that message received flag is 0
dat[5] = 0; // ensure that error flag is 0
dat[6] = 0;
dat[7] = "MY STRING";
RS485Master_Send(dat,1,160);
RCIE_bit = 1; // enable interrupt on UART1 receive
TXIE_bit = 0; // disable interrupt on UART1 transmit
PEIE_bit = 1; // enable peripheral interrupts
GIE_bit = 1; // enable all interrupts
while (1){
// upon completed valid message receiving
// data[4] is set to 255
cnt++;
if (dat[5]) { // if an error detected, signal it
PORTD = 0xAA; // by setting portd to 0xAA
}
if (dat[4]) { // if message received successfully
cnt = 0;
dat[4] = 0; // clear message received flag
j = dat[3];
for (i = 1; i <= dat[3]; i++) { // show data on PORTB
PORTB = dat[i-1];
} // increment received dat[0]
dat[0] = dat[0]+1; // send back to master
Delay_ms(1);
RS485Master_Send(dat,1,160);
}
if (cnt > 100000) {
PORTD ++;
cnt = 0;
RS485Master_Send(dat,1,160);
if (PORTD > 10) // if sending failed 10 times
RS485Master_Send(dat,1,50); // send message on broadcast address
}
}
}
Slave:
char dat[9]; // buffer for receving/sending messages
char i,j;
sbit rs485_rxtx_pin at RC2_bit; // set transcieve pin
sbit rs485_rxtx_pin_direction at TRISC2_bit; // set transcieve pin direction
// Interrupt routine
void interrupt() {
RS485Slave_Receive(dat);
}
void main() {
ANSEL = 0; // Configure AN pins as digital I/O
ANSELH = 0;
C1ON_bit = 0; // Disable comparators
C2ON_bit = 0;
PORTB = 0;
PORTD = 0;
TRISB = 0;
TRISD = 0;
PORTA = 0;
TRISA = 0;
UART1_Init(9600); // initialize UART1 module
Delay_ms(100);
RS485Slave_Init(160); // Intialize MCU as slave, address 160
dat[4] = 0; // ensure that message received flag is 0
dat[5] = 0; // ensure that message received flag is 0
dat[6] = 0; // ensure that error flag is 0
RCIE_bit = 1; // enable interrupt on UART1 receive
TXIE_bit = 0; // disable interrupt on UART1 transmit
PEIE_bit = 1; // enable peripheral interrupts
GIE_bit = 1; // enable all interrupts
while (1) {
if(dat[7]=="MY STRING"){
RCA0_bit = 1;
}
if (dat[5]) { // if an error detected, signal it by
PORTD = 0xAA; // setting portd to 0xAA
dat[5] = 0;
}
if (dat[4]) { // upon completed valid message receive
dat[4] = 0; // data[4] is set to 0xFF
j = dat[3];
for (i = 1; i <= dat[3];i++){
PORTB = dat[i-1];
}
dat[0] = dat[0]+1; // increment received dat[0]
Delay_ms(1);
RS485Slave_Send(dat,1); // and send it back to master
}
}
}
char dat[9]; defines an array of 9 bytes, so dat[7] = "MY STRING"; will only store a truncated address not the actual string. memcpy can be used to copy strings from one buffer to another.
see: http://www.cplusplus.com/reference/cstring/memcpy/
dat[7]=="MY STRING" will not work as your comparing the 2 byte address of the string literal "MY STRING" with the single byte stored at dat[7]. If you need to compare strings for differences, strcmp works.
see: http://www.cplusplus.com/reference/cstring/strcmp/