2 * Copyright Droids Corporation
3 * Olivier Matz <zer0@droids-corp.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Revision : $Id: ax12_user.c,v 1.2 2009-04-07 20:03:48 zer0 Exp $
24 #include <aversive/list.h>
25 #include <aversive/error.h>
31 #include <clock_time.h>
36 #include <control_system_manager.h>
37 #include <blocking_detection_manager.h>
41 #include <parse_string.h>
42 #include <parse_num.h>
47 * Cmdline interface for AX12. Use the PC to command a daisy-chain of
48 * AX12 actuators with a nice command line interface.
50 * The circuit should be as following:
53 * | uart3|------->--- PC (baudrate=57600)
57 * | uart0|---->---+-- AX12 (baudrate 115200)
61 * Note that RX and TX pins of UART1 are connected together to provide
62 * a half-duplex UART emulation.
66 #define UART_AX12_NUM 0
68 #define AX12_TIMEOUT 5000UL /* in us */
70 /********************************* AX12 commands */
73 * We use synchronous access (not interrupt driven) to the hardware
74 * UART, because we have to be sure that the transmission/reception is
75 * really finished when we return from the functions.
77 * We don't use the CM-5 circuit as described in the AX12
78 * documentation, we simply connect TX and RX and use TXEN + RXEN +
79 * DDR to manage the port directions.
82 static volatile uint8_t ax12_state = AX12_STATE_READ;
83 extern volatile struct cirbuf g_tx_fifo[]; /* uart fifo */
84 static volatile uint8_t ax12_nsent = 0;
86 /* Called by ax12 module to send a character on serial line. Count the
87 * number of transmitted bytes. It will be used in ax12_recv_char() to
88 * drop the bytes that we transmitted. */
89 static int8_t ax12_send_char(uint8_t c)
91 uart_send(UART_AX12_NUM, c);
101 /* called by uart module when the character has been written in
102 * UDR. It does not mean that the byte is physically transmitted. */
103 static void ax12_send_callback(char c)
105 if (ax12_state == AX12_STATE_READ) {
106 /* disable TX when last byte is pushed. */
107 if (CIRBUF_IS_EMPTY(&g_tx_fifo[UART_AX12_NUM]))
108 UCSRxB &= ~(1<<TXEN);
112 /* Called by ax12 module when we want to receive a char. Note that we
113 * also receive the bytes we sent ! So we need to drop them. */
114 static int16_t ax12_recv_char(void)
116 microseconds t = time_get_us2();
119 c = uart_recv_nowait(UART_AX12_NUM);
127 if ((time_get_us2() - t) > AX12_TIMEOUT)
133 /* called by ax12 module when we want to switch serial line. As we
134 * work in interruption mode, this function can be called to switch
135 * back in read mode even if the bytes are not really transmitted on
136 * the line. That's why in this case we do nothing, we will fall back
137 * in read mode in any case when xmit is finished -- see in
138 * ax12_send_callback() -- */
139 static void ax12_switch_uart(uint8_t state)
143 if (state == AX12_STATE_WRITE) {
146 while (uart_recv_nowait(UART_AX12_NUM) != -1);
148 ax12_state = AX12_STATE_WRITE;
153 if (CIRBUF_IS_EMPTY(&g_tx_fifo[UART_AX12_NUM]))
154 UCSRxB &= ~(1<<TXEN);
155 ax12_state = AX12_STATE_READ;
161 void ax12_user_init(void)
164 AX12_init(&gen.ax12);
165 AX12_set_hardware_send(&gen.ax12, ax12_send_char);
166 AX12_set_hardware_recv(&gen.ax12, ax12_recv_char);
167 AX12_set_hardware_switch(&gen.ax12, ax12_switch_uart);
168 uart_register_tx_event(UART_AX12_NUM, ax12_send_callback);