flm01/mote/v2/avr/basiciotest.c

207 lines
4.9 KiB
C

//
// basiciotest.c : test code for the io and buffer ops of the UART and SPI ports
//
// Copyright (c) 2010 flukso.net
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#include <avr/io.h>
#include <avr/interrupt.h>
#include "uart.h"
#include "spi.h"
#include "ctrl.h"
#define NO_OP_1 1
#define NO_OP_2 2
#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_FORWARD_TO_UART_PORT 'u'
#define SPI_FORWARD_TO_CTRL_PORT 'l' // 'l'ocal port
volatile uint8_t spi_status, high_hex;
// hex to binary/byte decoding
uint8_t htob(uint16_t hex)
{
uint8_t low_hex = (uint8_t) hex;
uint8_t high_hex = (uint8_t) (hex >> 8);
uint8_t byte;
byte = (high_hex > 0x40) ? (high_hex & 0x0F) + 9 : high_hex & 0x0F;
byte = byte << 4;
byte |= (low_hex > 0x40) ? (low_hex & 0x0F) + 9 : low_hex & 0x0F;
return byte;
}
// binary/byte to hex encoding
uint16_t btoh(uint8_t byte)
{
uint8_t low_nibble = (byte & 0x0F);
uint8_t high_nibble = (byte & 0xF0) >> 4;
uint16_t hex;
hex = (high_nibble > 0x09) ? high_nibble - 9 + 0x60 : high_nibble + 0x30;
hex = hex << 8;
hex |= (low_nibble > 0x09) ? low_nibble - 9 + 0x60 : low_nibble + 0x30;
return hex;
}
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)) {
spi_status--;
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 & HIGH_HEX) {
received_from_spi(high_hex);
spi_status &= ~HIGH_HEX;
return;
}
if (spi_status & TO_FROM_UART) {
if (!uartReceiveByte(&tx)) {
received_from_spi(SPI_END_OF_TX);
spi_status &= ~TRANSMIT;
spi_status |= NO_OP_2;
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 | START_TX;
spi_status &= ~(HIGH_HEX | TO_FROM_UART);
break;
case SPI_END_OF_MESSAGE:
if (!(spi_status & TO_FROM_UART)) {
ctrlAddToRxBuffer(spi_rx);
spi_status |= NEW_CTRL_MSG;
}
break;
case SPI_FORWARD_TO_UART_PORT:
spi_status |= TO_FROM_UART;
break;
case SPI_FORWARD_TO_CTRL_PORT:
spi_status &= ~TO_FROM_UART;
break;
default:
if (spi_status & HIGH_HEX) {
rx = htob(((uint16_t)high_hex << 8) + spi_rx);
if (spi_status & TO_FROM_UART) {
uartAddToTxBuffer(rx);
}
else {
ctrlAddToRxBuffer(rx);
}
}
else {
high_hex = spi_rx;
}
// toggle the HEX bit in spi_status
spi_status ^= HIGH_HEX;
}
}
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 hardware and buffers
uartInit();
// initialize the SPI in slave mode
setup_spi(SPI_MODE_0, SPI_MSB, SPI_INTERRUPT, SPI_SLAVE);
for(;;) {
if (spi_status & NEW_CTRL_MSG) {
ctrlRxToTxLoop();
spi_status &= ~NEW_CTRL_MSG;
}
}
return 0;
}