andras/ad-astra
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schmelczerandras 2020-04-19 12:48:06 +02:00
commit 26a0fd884f
173 changed files with 157458 additions and 1 deletions
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49
space_game/SpaceGame/src/driver/uart/receive.c Normal file
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#include <stdbool.h>
#include <avr/interrupt.h>
#include "receive.h"
#include "bitwise.h"
#include "../../hardware_access/hardware_access.h"
static struct {
uint16_t message;
uint8_t bitPosition; // goes from 0 to 9
bool previousValue;
uint8_t previousTimestamp;
OnCommandReceived onCommandReceived;
} uartReceive = {
.previousValue = true
};
void initializeUartReceive(OnCommandReceived onCommandReceived) {
setBit(PORTB, RECEIVE_PIN); // setup pull-up
setBit(PCMSK, RECEIVE_PIN); // enable interrupt on pin
uartReceive.onCommandReceived = onCommandReceived;
}
void handlePinChangeForUartReceive() {
bool currentValue = getBit(PINB, RECEIVE_PIN);
if (uartReceive.previousValue != currentValue) {
uint8_t elapsedBitCount = (getTimeSince(uartReceive.previousTimestamp) + BIT_TIME / 2) / BIT_TIME;
uartReceive.message >>= elapsedBitCount;
uartReceive.bitPosition += elapsedBitCount;
if (uartReceive.bitPosition == 9) {
uartReceive.onCommandReceived((uint8_t)(uartReceive.message));
uartReceive.bitPosition = 0;
}
if (uartReceive.previousValue == true && currentValue == false) {
if (uartReceive.bitPosition != elapsedBitCount) {
uartReceive.message |= (uint8_t)(0xFF << (8 - elapsedBitCount));
} else {
uartReceive.bitPosition = 0;
}
}
uartReceive.previousTimestamp = getTimestampFromFastTimer();
uartReceive.previousValue = currentValue;
}
}