Make RDF beacon only run on pad and after landing.

[fw/altos] / src / ao_radio.c

diff --git a/src/ao_radio.c b/src/ao_radio.c
index e4d42c6c32734b2f1542c9ae411c872a0bc3f6ef..76fa3e5dc497eb5f6913ca15e3fce8354cd8b2ff 100644 (file)
--- a/src/ao_radio.c
+++ b/src/ao_radio.c
@@ -223,7 +223,6 @@ static __code uint8_t rdf_setup[] = {
                                 (RDF_DEVIATION_M << RF_DEVIATN_DEVIATION_M_SHIFT)),
 
        /* packet length */
-       RF_PKTLEN_OFF,          RDF_PACKET_LEN,
        RF_PKTCTRL1_OFF,        ((1 << PKTCTRL1_PQT_SHIFT)|
                                 PKTCTRL1_ADR_CHK_NONE),
        RF_PKTCTRL0_OFF,        (RF_PKTCTRL0_PKT_FORMAT_NORMAL|
@@ -324,19 +323,32 @@ __xdata ao_radio_rdf_running;
 __xdata ao_radio_rdf_value = 0x55;
 
 void
-ao_radio_rdf(void)
+ao_radio_rdf(int ms)
 {
        uint8_t i;
+       uint8_t pkt_len;
        ao_mutex_get(&ao_radio_mutex);
        ao_radio_idle();
        ao_radio_rdf_running = 1;
        for (i = 0; i < sizeof (rdf_setup); i += 2)
                RF[rdf_setup[i]] = rdf_setup[i+1];
 
+       /*
+        * Compute the packet length as follows:
+        *
+        * 2000 bps (for a 1kHz tone)
+        * so, for 'ms' milliseconds, we need
+        * 2 * ms bits, or ms / 4 bytes
+        */
+       if (ms > (255 * 4))
+               ms = 255 * 4;
+       pkt_len = ms >> 2;
+       RF[RF_PKTLEN_OFF] = pkt_len;
+
        ao_dma_set_transfer(ao_radio_dma,
                            &ao_radio_rdf_value,
                            &RFDXADDR,
-                           RDF_PACKET_LEN,
+                           pkt_len,
                            DMA_CFG0_WORDSIZE_8 |
                            DMA_CFG0_TMODE_SINGLE |
                            DMA_CFG0_TRIGGER_RADIO,