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avr: improve the L2/L3 protocol on the SPI interface

This commit is contained in:
Bart Van Der Meerssche 2010-10-16 21:39:35 +02:00
parent 0e2405b496
commit 4d5a3a2a39
1 changed files with 89 additions and 62 deletions
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149
mote/v2/avr/basiciotest.c
View File

@ -19,32 +19,33 @@
//
// $Id$
#include <avr/io.h> // include I/O definitions (port names, pin names, etc)
#include <avr/interrupt.h> // include interrupt support
#include <avr/io.h>
#include <avr/interrupt.h>
#include "uart.h" // include uart function library
#include "uart.h"
#include "spi.h"
#include "ctrl.h"
#define NO_OP_1 1
#define NO_OP_2 2
#define TRANSMIT 4
#define HIGH_HEX 8
#define TO_FROM_UART 16
#define NEW_CTRL_MSG 32
#define START_TX 4
#define TRANSMIT 8
#define HIGH_HEX 16
#define TO_FROM_UART 32
#define NEW_CTRL_MSG 64
#define SPI_END_OF_TX 0x00
#define SPI_END_OF_MESSAGE ':'
#define SPI_END_OF_MESSAGE '.'
#define SPI_FORWARD_TO_UART_PORT 'u'
#define SPI_FORWARD_TO_CTRL_PORT 'l' // 'l'ocal port
volatile uint8_t high_hex;
volatile uint8_t spi_status;
volatile uint8_t spi_status, high_hex;
// hex to binary/byte decoding
uint8_t htob(uint16_t hex) {
uint8_t htob(uint16_t hex)
{
uint8_t low_hex = (uint8_t) hex;
uint8_t high_hex = (uint8_t) (hex >> 8);
uint8_t byte;
@ -56,7 +57,8 @@ uint8_t htob(uint16_t hex) {
}
// binary/byte to hex encoding
uint16_t btoh(uint8_t byte) {
uint16_t btoh(uint8_t byte)
{
uint8_t low_nibble = (byte & 0x0F);
uint8_t high_nibble = (byte & 0xF0) >> 4;
uint16_t hex;
@ -68,8 +70,10 @@ uint16_t btoh(uint8_t byte) {
}
SIGNAL(SPI_STC_vect) {
uint8_t spi_rx, spi_tx, uart_tx;
ISR(SPI_STC_vect)
{
uint8_t spi_rx, rx, tx;
uint16_t spi_tx;
// the SPI is double-buffered, requiring two NO_OPs when switching from Tx to Rx
if (spi_status & (NO_OP_1 | NO_OP_2)) {
@ -77,38 +81,58 @@ SIGNAL(SPI_STC_vect) {
return;
}
// do we have to transmit the first byte?
if (spi_status & START_TX) {
received_from_spi(SPI_FORWARD_TO_CTRL_PORT);
spi_status &= ~START_TX;
return;
}
// are we in Tx mode?
if (spi_status & TRANSMIT) {
if (spi_status & TO_FROM_UART) {
if (spi_status & HIGH_HEX) {
received_from_spi(high_hex);
spi_status &= ~HIGH_HEX;
return;
}
else {
if (ctrlGetFromTxBuffer(&spi_tx)) {
received_from_spi(spi_tx);
}
else {
if (spi_status & TO_FROM_UART) {
if (!uartReceiveByte(&tx)) {
received_from_spi(SPI_END_OF_TX);
spi_status &= ~TRANSMIT;
spi_status |= NO_OP_2;
uartAddToTxBuffer('r'); //debugging
return;
}
}
else {
if (ctrlGetFromTxBuffer(&tx)) {
if (tx == SPI_END_OF_MESSAGE) {
received_from_spi(tx);
return;
}
}
else {
received_from_spi(SPI_FORWARD_TO_UART_PORT);
spi_status |= TO_FROM_UART;
return;
}
}
spi_tx = btoh(tx);
high_hex = (uint8_t)spi_tx;
spi_status |= HIGH_HEX;
received_from_spi((uint8_t)(spi_tx >> 8));
return;
}
// we're in Rx mode
switch (spi_rx = received_from_spi(0x00)) {
case SPI_END_OF_TX:
spi_status |= TRANSMIT;
spi_status |= TRANSMIT | START_TX;
spi_status &= ~(HIGH_HEX | TO_FROM_UART);
uartAddToTxBuffer('t'); //debugging
break;
case SPI_END_OF_MESSAGE:
if (spi_status & TO_FROM_UART) {
spi_status &= ~TO_FROM_UART;
}
else {
if (!(spi_status & TO_FROM_UART)) {
ctrlAddToRxBuffer(spi_rx);
spi_status |= NEW_CTRL_MSG;
}
@ -120,57 +144,60 @@ SIGNAL(SPI_STC_vect) {
spi_status &= ~TO_FROM_UART;
break;
default:
//check whether the incoming hex-encoded stream needs to be forwarded to the UART port
if (spi_status & TO_FROM_UART) {
if (spi_status & HIGH_HEX) {
uart_tx = htob(((uint16_t)high_hex << 8) + spi_rx);
uartAddToTxBuffer(uart_tx);
if (spi_status & HIGH_HEX) {
rx = htob(((uint16_t)high_hex << 8) + spi_rx);
if (spi_status & TO_FROM_UART) {
uartAddToTxBuffer(rx);
}
else {
high_hex = spi_rx;
ctrlAddToRxBuffer(rx);
}
// toggle to the HEX bit in spi_status
spi_status ^= HIGH_HEX;
}
else {
// forward to CTRL_RX buffer
ctrlAddToRxBuffer(spi_rx);
high_hex = spi_rx;
}
// toggle the HEX bit in spi_status
spi_status ^= HIGH_HEX;
}
}
int main(void) {
ISR(TIMER1_COMPA_vect)
{
/* void */
}
int main(void)
{
// Configure PD5=DE as output pin with low as default
DDRD |= (1<<DDD5);
// Timer1 clock prescaler set to 1 => fTOV1 = 3686.4kHz / 65536 = 56.25Hz (DS p.134)
TCCR1B |= (1<<CS10);
// Increase sampling frequency to 2kHz (= 667Hz per channel) with an error of 0.01% (DS p.122)
OCR1A = 0x0732;
// Timer1 set to CTC mode (DS p.133)
TCCR1B |= 1<<WGM12;
// Enable output compare match interrupt for timer1 (DS p.136)
TIMSK1 |= (1<<OCIE1A);
#if DBG > 0
// Set PB1=OC1A as output pin
DDRB |= (1<<DDB1);
// Toggle pin OC1A=PB1 on compare match
TCCR1A |= 1<<COM1A0;
#endif
// initialize the CTRL buffers
ctrlInit();
// initialize the UART buffers with a default UART baud rate of 4800
// initialize the UART hardware and buffers
uartInit();
// initialize the SPI in slave mode
setup_spi(SPI_MODE_0, SPI_MSB, SPI_INTERRUPT, SPI_SLAVE);
uint8_t data;
uint16_t send;
for(;;) {
if (uartReceiveByte(&data)) {
// check the HEX bit in spi_status
if (spi_status & HIGH_HEX) {
// loopback on the UART itf
send = btoh(htob(((uint16_t)high_hex << 8) + data));
uartAddToTxBuffer((uint8_t)(send >> 8));
uartAddToTxBuffer((uint8_t)(send));
}
else {
high_hex = data;
}
// toggle to the HEX bit in spi_status
spi_status ^= HIGH_HEX;
}
if (spi_status & NEW_CTRL_MSG) {
ctrlLoop();
ctrlRxToTxLoop();
spi_status &= ~NEW_CTRL_MSG;
}
}