diff options
Diffstat (limited to 'fw/main.c')
| -rw-r--r-- | fw/main.c | 72 |
1 files changed, 57 insertions, 15 deletions
@@ -15,6 +15,7 @@ #include <unistd.h> #include "transpose.h" +#include "mac.h" /* * Part number: STM32F030F4C6 @@ -104,6 +105,7 @@ volatile union { struct __attribute__((packed)) { struct framebuf fb; uint8_t end[0]; } set_fb_rq; struct __attribute__((packed)) { uint8_t nbits; uint8_t end[0]; } set_nbits_rq; uint8_t byte_data[0]; + uint32_t mac_data; } rx_buf; volatile union { @@ -409,6 +411,7 @@ void uart_config(void) { #define LED_STRETCHING_MS 50 static volatile int error_led_timeout = 0; static volatile int comm_led_timeout = 0; +static volatile int id_led_timeout = 0; void trigger_error_led() { error_led_timeout = LED_STRETCHING_MS; @@ -418,32 +421,67 @@ void trigger_comm_led() { comm_led_timeout = LED_STRETCHING_MS; } +void trigger_id_led() { + id_led_timeout = LED_STRETCHING_MS; +} + /* Error counters for debugging */ static unsigned int overruns = 0; static unsigned int frame_overruns = 0; static unsigned int invalid = 0; +void tx_char(uint8_t c) { + while (!(USART1->ISR & USART_ISR_TC)); + USART1->TDR = c; +} + +void send_frame_formatted(uint8_t *buf, int len) { + uint8_t *p=buf, *q=buf, *end=buf+len; + do { + while (*q && q!=end) + q++; + tx_char(q-p+1); + while (*p && p!=end) + tx_char(*p++); + } while (p != end); + tx_char('\0'); +} + /* This is the higher-level protocol handler for the serial protocol. It gets passed the number of data bytes in this * frame (which may be zero) and returns a pointer to the buffer where the next frame should be stored. */ volatile uint8_t *packet_received(int len) { - static int protocol_state = 0; - /* Use zero-length frames as delimiters to synchronize this protocol layer */ - if (len == 0) { - protocol_state = 0; + static enum { + PROT_EXPECT_FRAME_FIRST_HALF = 0, + PROT_EXPECT_FRAME_SECOND_HALF = 1, + PROT_IGNORE = 2, + } protocol_state = PROT_IGNORE; + /* Use mac frames as delimiters to synchronize this protocol layer */ + trigger_comm_led(); + if (len == 0) { /* Discovery packet */ + if (sys_time < 100 && sys_time_seconds == 0) { /* Only respond during the first 100ms after boot */ + send_frame_formatted((uint8_t*)&device_mac, sizeof(device_mac)); + } + + } else if (len == 4) { /* Address packet */ + if (rx_buf.mac_data == device_mac) { /* we are addressed */ + protocol_state = PROT_EXPECT_FRAME_FIRST_HALF; /* start listening for frame buffer data */ + } else { /* we are not addressed */ + protocol_state = PROT_IGNORE; /* ignore packet */ + } } else if (len == sizeof(rx_buf.set_fb_rq)/2) { - if (protocol_state == 0) { /* First of two half-framebuffer data frames */ - protocol_state = 1; + if (protocol_state == PROT_EXPECT_FRAME_FIRST_HALF) { /* First of two half-framebuffer data frames */ + protocol_state = PROT_EXPECT_FRAME_SECOND_HALF; /* Return second half of receive buffer */ return rx_buf.byte_data + (sizeof(rx_buf.set_fb_rq)/2); - } else if (protocol_state == 1) { /* Second of two half-framebuffer data frames */ + } else if (protocol_state == PROT_EXPECT_FRAME_SECOND_HALF) { /* Second of two half-framebuffer data frames */ /* Kick off buffer transfer. This triggers the main loop to copy data out of the receive buffer and paste it * properly formatted into the frame buffer. */ if (fb_op == FB_WRITE) { fb_op = FB_FORMAT; - trigger_comm_led(); + trigger_id_led(); } else { /* FIXME An overrun happend. What should we do? */ frame_overruns++; @@ -451,14 +489,14 @@ volatile uint8_t *packet_received(int len) { } /* Go to "hang mode" until next zero-length packet. */ - protocol_state = 2; + protocol_state = PROT_IGNORE; } } else { /* FIXME An invalid packet has been received. What should we do? */ invalid++; trigger_error_led(); - protocol_state = 2; /* go into "hang mode" until next zero-length packet */ + protocol_state = PROT_IGNORE; /* go into "hang mode" until next zero-length packet */ } /* By default, return rx_buf.byte_data . This means if an invalid protocol state is reached ("hang mode"), the next @@ -720,10 +758,10 @@ int main(void) { int last_time = 0; while (42) { - /* Crude LED logic. The comm and error LEDs each have a timeout counter that is reset to the LED_STRETCHING_MS - * constant on an event (either a frame received correctly or some uart, framing or protocol error). These - * timeout counters count down in milliseconds and the LEDs are set while they are non-zero. This means a train - * of several very brief events will make the LED lit permanently. + /* Crude LED logic. The comm, id and error LEDs each have a timeout counter that is reset to the + * LED_STRETCHING_MS constant on an event (either a frame received correctly or some uart, framing or protocol + * error). These timeout counters count down in milliseconds and the LEDs are set while they are non-zero. This + * means a train of several very brief events will make the LED lit permanently. */ int time_now = sys_time; /* Latch sys_time here to avoid race conditions */ if (last_time != time_now) { @@ -737,7 +775,11 @@ int main(void) { if (comm_led_timeout < 0) comm_led_timeout = 0; - led_state = (led_state & ~3) | (!!error_led_timeout)<<1 | (!!comm_led_timeout)<<0; + id_led_timeout -= diff; + if (id_led_timeout < 0) + id_led_timeout = 0; + + led_state = (led_state & ~7) | (!!id_led_timeout)<<2 | (!!error_led_timeout)<<1 | (!!comm_led_timeout)<<0; last_time = time_now; } |