-#include "mbed.h"\r
-\r
-/**\r
- * Mode of operation:\r
- * Devices 1 and 2 synchronize clocks using serial messages.\r
- *\r
- * 1. Each serial message timestamped using the hardware timer capture\r
- * registers in both the sender and receiver.\r
- * 2. The sender transmits the send timestamp during the next time-sync\r
- * message.\r
- * 3. The receiver then compares the senders timestamp with it's own\r
- * timestamp for the corresponding messages and calculates an offset.\r
- * 4. The offset is used to compensate the receivers local clock.\r
- *\r
- * Time synchronization is performed in both directions.\r
- */\r
-\r
-/***********************\r
- * Message Definitions *\r
- ***********************/\r
-\r
-#define MSG_HEADER 0x1234\r
-\r
-typedef enum {\r
- MSG_ID_SYNC, // Time synchronization\r
- MSG_ID_EVENT, // Event occurred\r
-} msgid_t;\r
-\r
-typedef struct {\r
- uint32_t seconds; // Seconds since 1970 (without leap seconds)\r
- uint32_t nanosec; // Nanoseconds since 'seconds'\r
-} ntime_t;\r
-\r
-typedef struct {\r
- uint16_t header; // Message Header\r
- uint16_t mesgid; // Message ID\r
- uint16_t length; // Body length\r
- uint16_t cksum; // Body checksum\r
-} header_t;\r
-\r
-typedef struct {\r
- uint16_t seq; // Current sequence counter\r
- uint16_t prev; // Sequence of previous message\r
- ntime_t time; // Time of previous message\r
-} sync_msg_t;\r
-\r
-typedef struct {\r
- uint16_t device; // Device ID\r
- uint16_t event; // Event ID\r
- ntime_t time; // Timestamp\r
-} event_msg_t;\r
-\r
-/*******************\r
- * Timer functions *\r
- *******************/\r
-\r
-/**\r
- * Generate time stamp for an async event:\r
- * time: drift compensated wall-clock time\r
- * stamp: event timestamp from Timer/PWM Module\r
- */\r
-void time_stamp(ntime_t *time, uint32_t stamp)\r
-{\r
- // todo\r
-}\r
-\r
-/**\r
- * Compensate the Real-Time-Clock oscillator for\r
- * temperature and drift errors. Called at 1Hz and\r
- * synchronous to the RTC 1Hz output.\r
- */\r
-void time_rtc_comp(void)\r
-{\r
- // todo\r
-}\r
-\r
-/**\r
- * Synchronize the timer internal state with updates\r
- * from an external time sync message.\r
- * ours: our internal timestamp for the event\r
- * ref: reference timestamp from the other device\r
- */\r
-void time_ext_sync(ntime_t *ours, ntime_t *ref)\r
-{\r
- // todo\r
-}\r
-\r
-/************************\r
- * Serial I/O functions *\r
- ************************/\r
-\r
-/**\r
- * Output time sync message\r
- */\r
-void serial_send_sync(void)\r
-{\r
-}\r
-\r
-/**\r
- * Output external event received message\r
- * event: id of the received event\r
- * time: compensated timestamp of the event\r
- */\r
-void serial_send_event(uint16_t event, ntime_t *time)\r
-{\r
-}\r
-\r
-/**\r
- * Process serial receive messages\r
- */\r
-void serial_receive(void)\r
-{\r
-}\r
-\r
-/********************\r
- * Data definitions *\r
- ********************/\r
-\r
-// LEDs\r
-DigitalOut led1(LED1);\r
-DigitalOut led2(LED2);\r
-\r
-// UARTs tx rx\r
-Serial uart0(USBTX, USBRX);\r
-Serial uart1(PTE0, PTE1);\r
-Serial uart2(PTE16, PTE17);\r
-\r
-/********\r
- * Main *\r
- ********/\r
-\r
-void test_uart(void)\r
-{\r
- char xmt[32] = "hello, world";\r
- char rcv[32] = {};\r
-\r
- printf("start\r\n");\r
- for (int i = 0; xmt[i]; i++) {\r
- uart1.putc(xmt[i]);\r
- rcv[i] = uart2.getc();\r
- }\r
- printf("xmt: %s\r\n", xmt);\r
- printf("rcv: %s\r\n", rcv);\r
-}\r
-\r
-void test_leds(void)\r
-{\r
- led1 = 1; led2 = 0; wait(0.1);\r
- led1 = 0; led2 = 1; wait(0.1);\r
-}\r
-\r
-int main(int argc, char **argv)\r
-{\r
- uart0.baud(115200);\r
- uart1.baud(115200);\r
- uart2.baud(115200);\r
-\r
- test_uart();\r
- test_leds();\r
-\r
- while (1) {\r
- printf("tick\r\n");\r
- test_leds();\r
- }\r
-}\r
+#include "messages.h"
+
+#include "mbed.h"
+#include "serial_irq.h"
+#include "serial_dma.h"
+#include "timer_dma.h"
+
+/**
+ * Mode of operation:
+ * Devices 1 and 2 synchronize clocks using serial messages.
+ *
+ * 1. Each serial message timestamped using the hardware timer capture
+ * registers in both the sender and receiver.
+ * 2. The sender transmits the send timestamp during the next time-sync
+ * message.
+ * 3. The receiver then compares the senders timestamp with it's own
+ * timestamp for the corresponding messages and calculates an offset.
+ * 4. The offset is used to compensate the receivers local clock.
+ *
+ * Time synchronization is performed in both directions.
+ */
+
+/*******************
+ * Timer functions *
+ *******************/
+
+#define NSEC_PER_SEC 1000000000ULL
+
+uint64_t time_last_local; // timestamp at last time sync
+uint64_t time_last_world; // offset at last time sync
+
+/**
+ * Generate time stamp for an async event:
+ * time: drift compensated wall-clock time
+ * stamp: event timestamp from PIT Module
+ */
+uint64_t time_to_world(uint64_t local)
+{
+ uint64_t elapsed = local - time_last_local;
+ return time_last_world + elapsed;
+}
+
+uint64_t time_to_local(uint64_t world)
+{
+ uint64_t elapsed = world - time_last_world;
+ return time_last_local + elapsed;
+}
+
+/**
+ * Synchronize the timer internal state with updates
+ * from an external time sync message.
+ * local: our internal timestamp for the event
+ * world: reference timestamp from the other device
+ */
+void time_ext_init(uint64_t local, uint64_t world)
+{
+ sirq_printf("initialize clocks: %d -> %d\r\n",
+ (int)(local/NSEC_PER_SEC),
+ (int)(world/NSEC_PER_SEC));
+
+ time_last_local = local;
+ time_last_world = world;
+}
+
+/**
+ * Synchronize the timer internal state with updates
+ * from an external time sync message.
+ * local: our internal timestamp for the event
+ * world: reference timestamp from the other device
+ */
+void time_ext_sync(uint64_t local, uint64_t world)
+{
+ uint64_t guess = time_to_world(local);
+
+ time_last_local = local;
+ time_last_world = (guess/2) + (world/2);
+ //time_last_world = (guess * 3 / 4) + (world * 1 / 4);
+ //time_last_world =
+ // (guess - ( guess / 2)) +
+ // (world - (world - world / 2));
+ //time_last_world =
+ // (guess - (guess - guess / 4)) +
+ // (world - ( world / 4));
+
+ world = time_last_world;
+
+//#ifdef VERBOSE
+#if 0
+ uint64_t error = world > guess ? world - guess :
+ guess > world ? guess - world : 0;
+ int ahead = guess > world;
+ sirq_printf("syncing clocks: %6d=%d.%04u -> %d.%04u (err: %s%ld.%09lu)\r\n",
+ (int)((local / NSEC_PER_SEC)),
+ (int)((guess / NSEC_PER_SEC)),
+ (int)((guess % NSEC_PER_SEC)/(NSEC_PER_SEC/10000)),
+ (int)((world / NSEC_PER_SEC)),
+ (int)((world % NSEC_PER_SEC)/(NSEC_PER_SEC/10000)),
+ ahead ? "-" : " ",
+ (int32_t )(error / (int64_t)NSEC_PER_SEC),
+ (uint32_t)(error % (int64_t)NSEC_PER_SEC));
+#endif
+//#endif
+}
+
+void time_printf(const char *label, uint64_t local)
+{
+ uint64_t world = time_to_world(local);
+ sirq_printf("%s -- %d.%09u -> %d.%09u\r\n",
+ label,
+ (int)(local / NSEC_PER_SEC),
+ (int)(local % NSEC_PER_SEC),
+ (int)(world / NSEC_PER_SEC),
+ (int)(world % NSEC_PER_SEC));
+}
+
+/*********************
+ * Signal generation *
+ *********************/
+
+// for 50 Mhz clock 50/1000 = 1/20 (PLL/2)
+
+// for 48 Mhz clock 48/1000 = 6/125 (FLL)
+// for 24 Mhz clock, 24/1000 = 3/125
+// for 12 Mhz clock, 12/1000 = 3/250
+// for 6 Mhz clock, 6/1000 = 3/500
+// for 3 Mhz clock, 3/1000 = 3/1000
+
+#define EMIT_PS 1
+
+//#if EMIT_PS == 0
+//#define EMIT_CLOCKS(nsec) ((uint16_t)((nsec) / 20))
+//#define EMIT_NSEC(clocks) ((uint16_t)((clocks) * 20))
+
+#if EMIT_PS == 0
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 6 / 125))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 125 / 6))
+#elif EMIT_PS == 1
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 3 / 125))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 125 / 3))
+#elif EMIT_PS == 2
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 3 / 250))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 250 / 3))
+#elif EMIT_PS == 3
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 3 / 500))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 500 / 3))
+#elif EMIT_PS == 4
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 3 / 1000))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 1000 / 3))
+#endif
+
+static uint32_t *emit_pcr = 0; // transmit pin name
+
+static uint64_t emit_start = 0; // transmit start time (world time)
+static uint64_t emit_period = 0; // transmit period
+static uint64_t emit_due = 0; // next transmit (world time)
+
+static uint32_t emit_slack = 0; // how far ahead we need to schedule, in us
+static uint32_t emit_worst = 0; // worst-case latency in task table
+
+void emit_init(int alt, PinName pin, PinMode mode)
+{
+ // Find pin
+ emit_pcr = (uint32_t*)(PORTA_BASE + pin);
+
+ // Enable clocks
+ SIM->SCGC6 |= SIM_SCGC6_TPM1_MASK;
+ SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1);
+
+ // Reset PLL Source
+ //SIM->SOPT2 &= ~SIM_SOPT2_PLLFLLSEL_MASK;
+
+ // Debug print on SOPT2
+ // -- mbed may set PLLFLL when configuring UART0
+ // SOPT2: u0src=1 tpmsrc=1 USBSRC PLL/2 clkos=0 rtcos
+ sirq_printf("SOPT2: u0src=%d tpmsrc=%d %s %s clkos=%d %s\r\n",
+ (SIM->SOPT2 & SIM_SOPT2_UART0SRC_MASK) >> SIM_SOPT2_UART0SRC_SHIFT,
+ (SIM->SOPT2 & SIM_SOPT2_TPMSRC_MASK) >> SIM_SOPT2_TPMSRC_SHIFT,
+ (SIM->SOPT2 & SIM_SOPT2_UART0SRC_MASK) ? "USBSRC" : "usbsrc",
+ (SIM->SOPT2 & SIM_SOPT2_PLLFLLSEL_MASK) ? "PLL/2" : "FLL",
+ (SIM->SOPT2 & SIM_SOPT2_CLKOUTSEL_MASK) >> SIM_SOPT2_CLKOUTSEL_SHIFT,
+ (SIM->SOPT2 & SIM_SOPT2_RTCCLKOUTSEL_MASK) ? "RTCOS" : "rtcos");
+
+ // Set pin mode
+ emit_pcr[0] = PORT_PCR_ISF_MASK
+ | PORT_PCR_MUX(alt)
+ | mode;
+
+ // Setup Timer/PWM Module
+ TPM1->SC = TPM_SC_TOF_MASK;
+ TPM1->CNT = TPM_CNT_COUNT(0);
+ TPM1->MOD = TPM_MOD_MOD(0xFFFF);
+
+ TPM1->CONTROLS[0].CnSC = TPM_CnSC_CHF_MASK // clear flag
+ | TPM_CnSC_MSB_MASK // set output highon match,
+ | TPM_CnSC_ELSB_MASK // cleared on overflow
+ | TPM_CnSC_ELSA_MASK; // ..
+
+ TPM1->STATUS = TPM_STATUS_CH0F_MASK
+ | TPM_STATUS_TOF_MASK;
+
+ TPM1->CONF = TPM_CONF_CSOO_MASK;
+}
+
+void emit_enable(uint64_t start, uint64_t period)
+{
+ const int slack_clocks = 0x4000; // tune based on emit_worst
+
+ emit_start = start;
+ emit_period = period;
+ emit_due = start + period;
+
+ emit_slack = EMIT_NSEC(slack_clocks);
+
+ time_printf("emit scheduled", emit_due);
+}
+
+void emit_schedule(uint64_t when)
+{
+ uint64_t local = time_to_local(when) * 3 / 125;
+ uint32_t width = EMIT_CLOCKS(10000);
+
+ // Disable timer
+ TPM1->SC = TPM_SC_TOF_MASK;
+
+ __disable_irq();
+
+ uint64_t now = ((uint64_t)~PIT->LTMR64H << 32)
+ | ((uint64_t)~PIT->LTMR64L);
+ uint32_t delta = local - now;
+ uint32_t start = delta >> (EMIT_PS-1); // convert to clocks
+ uint32_t stop = start + width; // end time
+
+ // Set transmit time
+ TPM1->CONTROLS[0].CnV = start;
+ TPM1->MOD = TPM_MOD_MOD(stop);
+
+ // Start the timer
+ TPM1->SC = TPM_SC_TOF_MASK
+ | TPM_SC_PS(EMIT_PS)
+ | TPM_SC_CMOD(1);
+
+ __enable_irq();
+
+ // Test
+ //int64_t cnv = TPM1->CONTROLS[0].CnV;
+ //int64_t mod = TPM1->MOD;
+ //int64_t due = local - tdma_time();
+ //sirq_printf("%6d -- cnv=%04x mod=%04x due=%04x start=%04x\r\n",
+ // (int)(cnv - EMIT_CLOCKS(due)),
+ // (int)cnv, (int)mod,
+ // (int)EMIT_CLOCKS(due), EMIT_CLOCKS(start));
+
+ // Clock testing
+ //uint32_t test_tpm0 = TPM1->CNT;
+ //uint32_t test_pit0 = ~PIT->CHANNEL[0].CVAL;
+ //for (int i = 0; i < 100; i++)
+ // asm("nop");
+ //uint32_t test_tpm1 = TPM1->CNT;
+ //uint32_t test_pit1 = ~PIT->CHANNEL[0].CVAL;
+
+ //uint32_t test_tpm = test_tpm1 - test_tpm0;
+ //uint32_t test_pit = test_pit1 - test_pit0;
+ //sirq_printf("pit/tpm: %d - tpm=%08x/%08x=%d pit=%08x/%08x=%d\r\n",
+ // test_tpm - test_pit,
+ // test_tpm0, test_tpm1, test_tpm,
+ // test_pit0, test_pit1, test_pit);
+
+ // Debug output
+ //time_printf("emitting event", when);
+}
+
+void emit_transmit(uint64_t local, uint64_t world)
+{
+ static uint64_t prev = 0;
+
+ // Record how how much time we have to reschedule
+ if (prev && (local-prev) > emit_worst)
+ emit_worst = (local-prev);
+ prev = local;
+
+ // Schedule task if needed
+ if (emit_due && emit_period &&
+ world+emit_slack > emit_due) {
+ emit_schedule(emit_due);
+ emit_due += emit_period;
+ }
+}
+
+/************************
+ * Serial I/O functions *
+ ************************/
+
+typedef struct {
+ int index;
+ int state;
+ uint8_t buffer[256];
+} parser_t;
+
+static uint32_t serial_device_id = 0;
+
+const uint64_t serial_sync_delay = NSEC_PER_SEC / 100;
+static uint64_t serial_sync_due = 0;
+
+static tdma_t *serial_tdma_rcv = NULL;
+static tdma_t *serial_tdma_xmt = NULL;
+
+/**
+ * Convert world to local time
+ */
+uint64_t serial_read_time(ntime_t time)
+{
+ return ((uint64_t)time.seconds) * NSEC_PER_SEC
+ + ((uint64_t)time.nanosec);
+}
+
+ntime_t serial_write_time(uint64_t time)
+{
+ ntime_t buf = {};
+ buf.seconds = time / NSEC_PER_SEC;
+ buf.nanosec = time % NSEC_PER_SEC;
+ return buf;
+}
+
+int serial_time_stamp(tdma_t *port, uint64_t *local, uint64_t *world,
+ const char *msg)
+{
+ int valid = tdma_stamp(port, local);
+ *world = time_to_world(*local);
+
+ if (!valid)
+ sirq_printf("%s -- missing\r\n", msg);
+ //else
+ // time_printf(msg, current);
+
+ return valid;
+}
+
+/**
+ * Output initialization message init message
+ */
+void serial_send_init(uint16_t device, uint64_t local)
+{
+}
+
+/**
+ * Output time sync message
+ */
+void serial_send_sync(sirq_t *port, uint64_t now)
+{
+ if (serial_sync_due == 0 || now < serial_sync_due)
+ return; // not ready
+
+ // Message data
+ header_t head;
+ sync_msg_t body;
+
+ // Write header
+ head.header = MSG_HEADER;
+ head.msgid = MSG_ID_SYNC;
+ head.length = sizeof(body);
+ head.cksum = 0; // todo
+
+ tdma_stop(serial_tdma_rcv, 0);
+ tdma_start(serial_tdma_xmt);
+
+ sirq_write(port, &head, sizeof(head));
+
+ tdma_stop(serial_tdma_xmt, 100);
+ tdma_start(serial_tdma_rcv);
+
+ // Save transmit time
+ uint64_t local = 0, world = 0;
+ serial_time_stamp(serial_tdma_xmt, &local, &world,
+ "sync time transmit");
+
+ // Debug output
+ //sirq_printf("sync time transmit\r\n");
+ //time_printf(" local", local);
+ //time_printf(" world", world);
+
+ // Write body with updated time and send
+ body.time = serial_write_time(world);
+
+ sirq_write(port, &body, sizeof(body));
+
+ // Queue next transmit time
+ serial_sync_due = 0;
+}
+
+/**
+ * Output external event received message
+ * event: id of the received event
+ * time: compensated timestamp of the event
+ */
+void serial_send_event(sirq_t *port, uint16_t event, uint64_t local)
+{
+ //time_printf("event received", local);
+
+ // Convert timestamp
+ uint64_t world = time_to_world(local);
+ ntime_t ltime = serial_write_time(local);
+ ntime_t wtime = serial_write_time(world);
+
+ // Message data
+ header_t head = {};
+ event_msg_t body = {};
+
+ // Transmit sync message
+ head.header = MSG_HEADER;
+ head.msgid = MSG_ID_EVENT;
+ head.length = sizeof(body);
+ head.cksum = 0; // todo
+
+ body.device = serial_device_id;
+ body.event = event;
+ body.world = wtime;
+ body.local = ltime;
+
+ // Transmit message to BBB
+ sirq_write(port, &head, sizeof(head));
+ sirq_write(port, &body, sizeof(body));
+}
+
+/**
+ * Handle init message
+ */
+void serial_handle_init(init_msg_t *msg)
+{
+ sirq_printf("initialize: %s %s %s %s %s\r\n",
+ msg->valid & MSG_VALID_DEVICE ? "DEV" : "dev",
+ msg->valid & MSG_VALID_START ? "START" : "start",
+ msg->valid & MSG_VALID_PERIOD ? "PERIOD" : "period",
+ msg->valid & MSG_VALID_WORLD ? "WORLD" : "world",
+ msg->valid & MSG_VALID_SYNC ? "SYNC" : "sync");
+ sirq_printf(" dev -- %d\r\n", msg->device);
+ time_printf(" start ", serial_read_time(msg->start));
+ time_printf(" period", serial_read_time(msg->period));
+ time_printf(" world ", serial_read_time(msg->world));
+
+ if (msg->valid & MSG_VALID_DEVICE)
+ serial_device_id = msg->device;
+
+ if (msg->valid & MSG_VALID_START ||
+ msg->valid & MSG_VALID_PERIOD) {
+ uint64_t start = serial_read_time(msg->start);
+ uint64_t period = serial_read_time(msg->period);
+ emit_enable(start, period);
+ }
+
+ if (msg->valid & MSG_VALID_WORLD) {
+ uint64_t world = serial_read_time(msg->world);
+ uint64_t local = tdma_time();
+ time_ext_init(local, world);
+ }
+
+ if (msg->valid & MSG_VALID_SYNC)
+ serial_sync_due = tdma_time() + serial_sync_delay;
+}
+
+/**
+ * Handle sync message
+ */
+void serial_handle_sync(sync_msg_t *msg)
+{
+ // Read receive timestamp
+ uint64_t local = 0, world = 0;
+ serial_time_stamp(serial_tdma_rcv, &local, &world,
+ "sync time receive ");
+ tdma_stop(serial_tdma_rcv, 0);
+
+ // Lookup reference time from message
+ uint64_t reference = serial_read_time(msg->time);
+
+ // Debug output
+ //sirq_printf("sync time receive\r\n");
+ //time_printf(" local", local);
+ //time_printf(" world", world);
+ //time_printf(" ref ", reference);
+
+ // Synchronize the clocks
+ time_ext_sync(local, reference);
+
+ // Queue transmit to other board
+ serial_sync_due = tdma_time() + serial_sync_delay;
+}
+
+/**
+ * Handle event message
+ */
+void serial_handle_event(event_msg_t *msg)
+{
+}
+
+/**
+ * Deliver message
+ */
+void serial_deliver(int msgid, void *body)
+{
+ switch (msgid) {
+ case MSG_ID_INIT:
+ //sirq_printf("received init msg\r\n");
+ serial_handle_init((init_msg_t*)body);
+ break;
+ case MSG_ID_SYNC:
+ //sirq_printf("received sync msg\r\n");
+ serial_handle_sync((sync_msg_t*)body);
+ break;
+ case MSG_ID_EVENT:
+ //sirq_printf("received event msg\r\n");
+ serial_handle_event((event_msg_t*)body);
+ break;
+ }
+}
+
+/**
+ * Process serial receive messages
+ */
+void serial_receive(parser_t *parser, int byte)
+{
+ //sirq_printf("serial_receive - %02x\r\n", byte);
+
+ // Lookup pointers
+ header_t *head = (header_t*)parser->buffer;
+ void *body = (void*)(head+1);
+ const int max_length = sizeof(parser->buffer)-sizeof(header_t);
+
+ // Process uart messages
+ parser->buffer[parser->index++] = byte;
+ switch (parser->state) {
+ case 0: // Search
+ if (parser->index == sizeof(uint16_t)) {
+ if (head->header == MSG_HEADER) {
+ parser->state = 1;
+ } else {
+ parser->buffer[0] = parser->buffer[1];
+ parser->index = 1;
+ }
+ }
+ break;
+ case 1: // Header
+ if (parser->index == sizeof(header_t)) {
+ if (head->length <= max_length &&
+ head->msgid <= MSG_MAX_ID) {
+ parser->state = 2;
+ } else {
+ parser->index = 0;
+ parser->state = 0;
+ }
+ }
+ break;
+ case 2: // Data
+ if (parser->index == (int)sizeof(header_t)+head->length) {
+ serial_deliver(head->msgid, body);
+ parser->index = 0;
+ parser->state = 0;
+ }
+ break;
+ }
+}
+
+/********************
+ * Data definitions *
+ ********************/
+
+// LEDs
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+
+// Message Parsers
+parser_t parser_dbg;
+parser_t parser_bbb;
+parser_t parser_mbed;
+
+// Serial IRQ
+sirq_t *sirq_dbg;
+sirq_t *sirq_bbb;
+sirq_t *sirq_mbed;
+
+// Timer DMA
+tdma_t *tdma_evt;
+tdma_t *tdma_rcv;
+tdma_t *tdma_xmt;
+
+/*********
+ * Tasks *
+ *********/
+
+void task_serial(uint64_t local, uint64_t world)
+{
+ while (sirq_ready(sirq_dbg)) {
+ //sirq_printf("serial recv - dbg\r\n");
+ serial_receive(&parser_dbg, sirq_getc(sirq_dbg));
+ }
+
+ while (sirq_ready(sirq_bbb)) {
+ //sirq_printf("serial recv - bbb\r\n");
+ serial_receive(&parser_bbb, sirq_getc(sirq_bbb));
+ }
+
+ while (sirq_ready(sirq_mbed)) {
+ //sirq_printf("serial recv - mbed\r\n");
+ serial_receive(&parser_mbed, sirq_getc(sirq_mbed));
+ }
+}
+
+void task_events(uint64_t local, uint64_t world)
+{
+ uint64_t event = 0;
+
+#ifdef VERBOSE
+ if (tdma_stamp(tdma_evt, &event)) {
+ sirq_printf("event received - evt\r\n");
+ if (tdma_stamp(tdma_rcv, &event))
+ sirq_printf("event received - rcv\r\n");
+ if (tdma_stamp(tdma_xmt, &event))
+ sirq_printf("event received - xmt\r\n");
+#endif
+
+ if (tdma_stamp(tdma_evt, &event))
+ serial_send_event(sirq_bbb, 0, event);
+ tdma_stop(tdma_evt, 0);
+ tdma_start(tdma_evt);
+}
+
+void task_sync(uint64_t local, uint64_t world)
+{
+ serial_send_sync(sirq_mbed, local);
+}
+
+void task_leds(uint64_t local, uint64_t world)
+{
+ static uint32_t which = 0;
+ led1 = (which == 0);
+ led2 = (which == 1);
+ which ^= 1;
+}
+
+void task_emit(uint64_t local, uint64_t world)
+{
+ emit_transmit(local, world);
+}
+
+void task_debug(uint64_t local, uint64_t world)
+{
+ //tdma_debug(tdma_rcv);
+ //tdma_debug(tdma_xmt);
+
+ //sirq_debug(sirq_mbed);
+
+ //serial_send_event(sirq_bbb, 1, local);
+
+#ifdef VERBOSE
+ sirq_printf("background - %6u.%02u -> %u.%02u\r\n",
+ (uint32_t)(local / NSEC_PER_SEC),
+ (uint32_t)(local % NSEC_PER_SEC / 10000000),
+ (uint32_t)(world / NSEC_PER_SEC),
+ (uint32_t)(world % NSEC_PER_SEC / 10000000));
+#endif
+}
+
+/********
+ * Main *
+ ********/
+
+#define N_ELEM(x) (sizeof(x) / sizeof((x)[0]))
+
+extern void test_main(void);
+extern serial_t stdio_uart;
+
+static struct {
+ void (*task)(uint64_t, uint64_t);
+ uint64_t period;
+ uint64_t due;
+} tasks[] = {
+ { task_serial, 0 }, // always
+ { task_events, 0 }, // always -- testing
+ { task_sync, 0 }, // always
+ { task_emit, 0 }, // always
+ { task_leds, 100000000 }, // 10hz
+ { task_debug, 1000000000 }, // 1hz
+};
+
+void background(void)
+{
+ // Debugging
+ uint64_t local = tdma_time();
+ uint64_t world = time_to_world(local);
+
+ // Run the scheduler
+ for (unsigned i = 0; i < N_ELEM(tasks); i++) {
+ if (local >= tasks[i].due) {
+ tasks[i].task(local, world);
+ tasks[i].due += tasks[i].period;
+ }
+ }
+}
+
+int main(int argc, char **argv)
+{
+ tdma_init();
+
+ //pin = 1;
+
+ // Open serial ports
+ sirq_dbg = sirq_open(SIRQ_UART0, USBTX, USBRX, 115200); // to pc
+ sirq_bbb = sirq_open(SIRQ_UART1, PTE0, PTE1, 115200); // to bbb
+ sirq_mbed = sirq_open(SIRQ_UART2, PTD3, PTD2, 115200); // to mbed
+
+ // Setup timers
+ tdma_evt = tdma_open(TDMA_CHAN0, 3, PTC9, PullDown); // async event
+
+ // mbed time sync
+ tdma_rcv = tdma_open(TDMA_CHAN2, 3, PTD2, PullUp); // time sync rcv
+ tdma_xmt = tdma_open(TDMA_CHAN3, 3, PTD3, PullUp); // time sync xmt
+
+ // host time sync
+ //tdma_rcv = tdma_open(TDMA_CHAN2, 2, USBRX, PullUp); // time sync rcv
+ //tdma_xmt = tdma_open(TDMA_CHAN3, 2, USBTX, PullUp); // time sync xmt
+
+ // start timers
+ tdma_start(tdma_evt);
+ tdma_start(tdma_rcv);
+ tdma_start(tdma_xmt);
+
+ // Serial timestamping
+ serial_tdma_rcv = tdma_rcv;
+ serial_tdma_xmt = tdma_xmt;
+
+ // Setup event generation
+ emit_init(3, PTE20, PullDown);
+
+ // Run background loop
+ while (true)
+ background();
+
+ // Run tests
+ //test_main();
+
+ return 0;
+}