This version of the famous Grbl adds values in the work-coordinate-system (WCS) to the probing command. See x2grbl why you might want this.

serial.c 6.4KB

    /* serial.c - Low level functions for sending and recieving bytes via the serial port Part of Grbl v0.9 Copyright (c) 2012-2014 Sungeun K. Jeon Grbl 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 3 of the License, or (at your option) any later version. Grbl 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 Grbl. If not, see <http://www.gnu.org/licenses/>. */ /* This file is based on work from Grbl v0.8, distributed under the terms of the MIT-license. See COPYING for more details. Copyright (c) 2009-2011 Simen Svale Skogsrud Copyright (c) 2011-2012 Sungeun K. Jeon */ #include <avr/interrupt.h> #include "system.h" #include "serial.h" #include "motion_control.h" #include "protocol.h" uint8_t serial_rx_buffer[RX_BUFFER_SIZE]; uint8_t serial_rx_buffer_head = 0; volatile uint8_t serial_rx_buffer_tail = 0; uint8_t serial_tx_buffer[TX_BUFFER_SIZE]; uint8_t serial_tx_buffer_head = 0; volatile uint8_t serial_tx_buffer_tail = 0; #ifdef ENABLE_XONXOFF volatile uint8_t flow_ctrl = XON_SENT; // Flow control state variable #endif // Returns the number of bytes used in the RX serial buffer. uint8_t serial_get_rx_buffer_count() { uint8_t rtail = serial_rx_buffer_tail; // Copy to limit multiple calls to volatile if (serial_rx_buffer_head >= rtail) { return(serial_rx_buffer_head-rtail); } return (RX_BUFFER_SIZE - (rtail-serial_rx_buffer_head)); } // Returns the number of bytes used in the TX serial buffer. // NOTE: Not used except for debugging and ensuring no TX bottlenecks. uint8_t serial_get_tx_buffer_count() { uint8_t ttail = serial_tx_buffer_tail; // Copy to limit multiple calls to volatile if (serial_tx_buffer_head >= ttail) { return(serial_tx_buffer_head-ttail); } return (TX_BUFFER_SIZE - (ttail-serial_tx_buffer_head)); } void serial_init() { // Set baud rate #if BAUD_RATE < 57600 uint16_t UBRR0_value = ((F_CPU / (8L * BAUD_RATE)) - 1)/2 ; UCSR0A &= ~(1 << U2X0); // baud doubler off - Only needed on Uno XXX #else uint16_t UBRR0_value = ((F_CPU / (4L * BAUD_RATE)) - 1)/2; UCSR0A |= (1 << U2X0); // baud doubler on for high baud rates, i.e. 115200 #endif UBRR0H = UBRR0_value >> 8; UBRR0L = UBRR0_value; // enable rx and tx UCSR0B |= 1<<RXEN0; UCSR0B |= 1<<TXEN0; // enable interrupt on complete reception of a byte UCSR0B |= 1<<RXCIE0; // defaults to 8-bit, no parity, 1 stop bit } // Writes one byte to the TX serial buffer. Called by main program. // TODO: Check if we can speed this up for writing strings, rather than single bytes. void serial_write(uint8_t data) { // Calculate next head uint8_t next_head = serial_tx_buffer_head + 1; if (next_head == TX_BUFFER_SIZE) { next_head = 0; } // Wait until there is space in the buffer while (next_head == serial_tx_buffer_tail) { // TODO: Restructure st_prep_buffer() calls to be executed here during a long print. if (sys.execute & EXEC_RESET) { return; } // Only check for abort to avoid an endless loop. } // Store data and advance head serial_tx_buffer[serial_tx_buffer_head] = data; serial_tx_buffer_head = next_head; // Enable Data Register Empty Interrupt to make sure tx-streaming is running UCSR0B |= (1 << UDRIE0); } // Data Register Empty Interrupt handler ISR(SERIAL_UDRE) { uint8_t tail = serial_tx_buffer_tail; // Temporary serial_tx_buffer_tail (to optimize for volatile) #ifdef ENABLE_XONXOFF if (flow_ctrl == SEND_XOFF) { UDR0 = XOFF_CHAR; flow_ctrl = XOFF_SENT; } else if (flow_ctrl == SEND_XON) { UDR0 = XON_CHAR; flow_ctrl = XON_SENT; } else #endif { // Send a byte from the buffer UDR0 = serial_tx_buffer[tail]; // Update tail position tail++; if (tail == TX_BUFFER_SIZE) { tail = 0; } serial_tx_buffer_tail = tail; } // Turn off Data Register Empty Interrupt to stop tx-streaming if this concludes the transfer if (tail == serial_tx_buffer_head) { UCSR0B &= ~(1 << UDRIE0); } } // Fetches the first byte in the serial read buffer. Called by main program. uint8_t serial_read() { uint8_t tail = serial_rx_buffer_tail; // Temporary serial_rx_buffer_tail (to optimize for volatile) if (serial_rx_buffer_head == tail) { return SERIAL_NO_DATA; } else { uint8_t data = serial_rx_buffer[tail]; tail++; if (tail == RX_BUFFER_SIZE) { tail = 0; } serial_rx_buffer_tail = tail; #ifdef ENABLE_XONXOFF if ((serial_get_rx_buffer_count() < RX_BUFFER_LOW) && flow_ctrl == XOFF_SENT) { flow_ctrl = SEND_XON; UCSR0B |= (1 << UDRIE0); // Force TX } #endif return data; } } ISR(SERIAL_RX) { uint8_t data = UDR0; uint8_t next_head; // Pick off runtime command characters directly from the serial stream. These characters are // not passed into the buffer, but these set system state flag bits for runtime execution. switch (data) { case CMD_STATUS_REPORT: bit_true_atomic(sys.execute, EXEC_STATUS_REPORT); break; // Set as true case CMD_CYCLE_START: bit_true_atomic(sys.execute, EXEC_CYCLE_START); break; // Set as true case CMD_FEED_HOLD: bit_true_atomic(sys.execute, EXEC_FEED_HOLD); break; // Set as true case CMD_RESET: mc_reset(); break; // Call motion control reset routine. default: // Write character to buffer next_head = serial_rx_buffer_head + 1; if (next_head == RX_BUFFER_SIZE) { next_head = 0; } // Write data to buffer unless it is full. if (next_head != serial_rx_buffer_tail) { serial_rx_buffer[serial_rx_buffer_head] = data; serial_rx_buffer_head = next_head; #ifdef ENABLE_XONXOFF if ((serial_get_rx_buffer_count() >= RX_BUFFER_FULL) && flow_ctrl == XON_SENT) { flow_ctrl = SEND_XOFF; UCSR0B |= (1 << UDRIE0); // Force TX } #endif } //TODO: else alarm on overflow? } } void serial_reset_read_buffer() { serial_rx_buffer_tail = serial_rx_buffer_head; #ifdef ENABLE_XONXOFF flow_ctrl = XON_SENT; #endif }