bool frudp_listen(const uint32_t max_usec)
{
// just busy-wait here for the requested amount of time
volatile uint32_t t_start = systime_usecs();
while (1)
{
enet_process_rx_ring();
volatile uint32_t t = systime_usecs();
if (t - t_start >= max_usec)
break;
}
return true;
}
void delay_ms(uint32_t ms)
{
// todo: care about wraparound
volatile uint32_t t_start = systime_usecs();
while (1)
{
volatile uint32_t t[2];
// poll time twice in case we happen to poll during timer wrap glitch
t[0] = systime_usecs();
t[1] = systime_usecs();
t[0] = t[1] < t[0] ? t[1] : t[0];
if (t[0] > t_start + 1000 * ms)
break;
}
}
void dmxl_tick()
{
volatile uint32_t t = systime_usecs();
bool start_poll = false;
if (t - g_dmxl_last_poll_time > DMXL_POLL_INTERVAL_USEC)
{
//start_poll = true;
//printf("%d dmxl poll\r\n", (int)SYSTIME);
if (g_dmxl_last_poll_time)
g_dmxl_last_poll_time += DMXL_POLL_INTERVAL_USEC;
else
g_dmxl_last_poll_time = t;
}
// process the rx ring
dmxl_chain_t *c = &g_dmxl_chain;
while (c->rx_rpos != c->rx_wpos)
{
dmxl_process_byte(c, c->rxbuf[c->rx_rpos++]);
__disable_irq();
if (c->rx_rpos >= DMXL_CHAIN_RXBUF_LEN)
c->rx_rpos = 0;
__enable_irq();
}
// run the port state machine
switch (c->port_state)
{
case DMXL_PORT_STATE_IDLE:
if (start_poll)
{
USART1->CR1 &= ~USART_CR1_RE;
c->port_state = DMXL_PORT_STATE_POLL_TX_EN;
c->polling_id = c->id_base; // start with first servo
c->t_state = t;
dmxl_stuff_poll_pkt(c);
pin_set_output_state(GPIOB, DMXL_PORTB_TXE_PIN, 1); // assert TXE
}
break;
case DMXL_PORT_STATE_POLL_TX_EN:
if (t - c->t_state > 3)
{
//printf("starting dmxl poll\r\n");
c->tx_byte_idx = 0;
USART1->DR = c->txbuf[0];
c->port_state = DMXL_PORT_STATE_POLL_TX;
c->t_state = systime_usecs();
}
break;
case DMXL_PORT_STATE_POLL_TX:
if ((USART1->SR & USART_SR_TXE) || systime_usecs() - c->t_state > 100)
{
if (c->tx_byte_idx >= c->tx_pkt_len - 1)
{
c->port_state = DMXL_PORT_STATE_POLL_TX_LAST;
c->t_state = systime_usecs();
}
else
USART1->DR = c->txbuf[++c->tx_byte_idx];
}
break;
case DMXL_PORT_STATE_POLL_TX_LAST:
if ((USART1->SR & USART_SR_TC) || systime_usecs() - c->t_state > 100)
{
c->port_state = DMXL_PORT_STATE_POLL_TX_DIS;
c->t_state = systime_usecs();
c->parser_state = DMXL_PARSER_STATE_PREAMBLE_0;
}
break;
case DMXL_PORT_STATE_POLL_TX_DIS:
if (systime_usecs() - c->t_state > 2)
{
pin_set_output_state(GPIOB, DMXL_PORTB_TXE_PIN, 0); // de-assert TXE
c->port_state = DMXL_PORT_STATE_POLL_RX;
c->t_state = systime_usecs();
USART1->CR1 |= USART_CR1_RE;
//printf("%d starting rx\r\n", (int)SYSTIME);
}
break;
case DMXL_PORT_STATE_POLL_RX:
if ((c->parser_state == DMXL_PARSER_STATE_DONE) ||
(systime_usecs() - c->t_state > 1000))
{
// if we haven't heard from it by 1ms, we're toast anyway
//printf("%d exiting rx\r\n", (int)SYSTIME);
// we need to either start polling the next servo, or we're done.
c->polling_id++;
//printf("%d poll complete\r\n", (int)SYSTIME);
if (c->polling_id > c->num_nodes)
c->port_state = DMXL_PORT_STATE_IDLE;
else
c->port_state = DMXL_PORT_STATE_POLL_RX_WAIT;
dmxl_stuff_poll_pkt(c);
USART1->CR1 &= ~USART_CR1_RE;
c->t_state = systime_usecs();
}
break;
case DMXL_PORT_STATE_POLL_RX_WAIT:
if (systime_usecs() - c->t_state > 100)
{
c->port_state = DMXL_PORT_STATE_POLL_TX_EN;
pin_set_output_state(GPIOB, DMXL_PORTB_TXE_PIN, 1); // assert TXE
c->t_state = systime_usecs();
}
break;
default:
g_dmxl_chain.port_state = DMXL_PORT_STATE_IDLE;
}
}
void delay_ms(uint32_t ms)
{
// todo: care about wraparound
volatile uint32_t t_start = systime_usecs();
while (t_start + 1000 * ms > systime_usecs()) { }
}
