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Start supporting antenna diversity
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Unconditionally enable the antenna diversity circuit onboard Si1060.
It should then automatically pick the better antenna (out of two
options) for reception of each packet.

Use the signal strength evaluation obtained at last packet reception
to choose the antenna used for transmission (this latter behavior is
implemented solely in software).
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@povik
povik committed Nov 16, 2021
1 parent 2aee335 commit 435091a
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Showing 2 changed files with 90 additions and 47 deletions.
4 changes: 2 additions & 2 deletions Firmware/radio/at.c
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Original file line number Diff line number Diff line change
Expand Up @@ -585,7 +585,7 @@ at_plus(void)
}
return;
#endif //BOARD_rfd900a / BOARD_rfd900p
#ifdef RFD900_DIVERSITY
#if defined RFD900_DIVERSITY || defined BOARD_ism01a
case 'A':
if (at_cmd[4] != '=')
{
Expand All @@ -601,7 +601,7 @@ at_plus(void)
}
at_ok();
return;
#endif // RFD900_DIVERSITY
#endif // RFD900_DIVERSITY / BOARD_ism01a
}
at_error();
}
133 changes: 88 additions & 45 deletions Firmware/radio/radio_446x.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -117,6 +117,9 @@ __pdata struct radio_settings settings;
static bool software_reset(void);
static void set_frequency_registers(__pdata uint32_t base_freq, __pdata uint32_t freq_spacing);

enum DIVERSITY_Enum diversity_saved;
static void radio_set_diversity_gpio(enum DIVERSITY_Enum state);

#define TX_FIFO_THRESHOLD 0x40
#define RX_FIFO_THRESHOLD 0x40

Expand Down Expand Up @@ -328,6 +331,7 @@ radio_transmit_simple(uint8_t length, __xdata uint8_t * __pdata buf, __pdata uin
__pdata uint16_t tstart;
__data uint8_t n, len_remaining;
uint8_t chip_status, ph_status, tx_space;
int16_t ant1, ant2;

tstart = timer2_tick();

Expand All @@ -338,6 +342,17 @@ radio_transmit_simple(uint8_t length, __xdata uint8_t * __pdata buf, __pdata uin

EX0_RESTORE;

if (diversity_saved == DIVERSITY_ENABLED) {
cmd_get_modem_status(0xff);
get_modem_status_reply(
_skip, _skip, _skip, _skip, ant1, ant2, _skip
);
if (ant2 > ant1)
radio_set_diversity_gpio(DIVERSITY_ANT2);
else
radio_set_diversity_gpio(DIVERSITY_ANT1);
}

cmd_get_int_status_clear_all();
wait_for_cts();

Expand Down Expand Up @@ -393,6 +408,7 @@ radio_transmit_simple(uint8_t length, __xdata uint8_t * __pdata buf, __pdata uin
}

if (ph_status & PH_STATUS_PACKET_SENT) {
radio_set_diversity_gpio(diversity_saved);
return true;
}
}
Expand All @@ -408,6 +424,10 @@ radio_transmit_simple(uint8_t length, __xdata uint8_t * __pdata buf, __pdata uin
cmd_change_state(STATE_READY);
wait_for_cts();

if (diversity_saved == DIVERSITY_ENABLED) {
radio_set_diversity_gpio(diversity_saved);
}

/* here we assume we are out of TX state, so that the FIFO reset is safe to do */
cmd_fifo_info(0x03);
wait_for_cts();
Expand Down Expand Up @@ -551,8 +571,25 @@ check_part(void) __reentrant
return part == 0x4463;
}

static void radio_gpio_init()
// initialise the radio hardware
//
bool
radio_initialise(void)
{
/* TODO: check timing */
SDN = 1;
delay_msec(1);
SDN = 0;
delay_msec(6);

wait_for_cts();

cmd_power_up(0x1, 0x0, 30000000);
wait_for_cts();

if (!check_part())
return false;

cmd_set_property4(GROUP_FRR_CTL, 0x0,
10, /* FRR A = latched RSSI */
7, /* FRR B = INT_CHIP_STATUS */
Expand Down Expand Up @@ -580,39 +617,6 @@ static void radio_gpio_init()
cmd_set_property1(GROUP_GLOBAL, 0x01, 0x48);
wait_for_cts();

cmd_gpio_pin_cfg(
0x40 | GPIO_0_CONFIG,
0x40 | GPIO_1_CONFIG,
0x40 | 8, // 2: CTS
0x40 | 33, // GPIO4: RX state
39, // nIRQ
0, // SDO
2
);
wait_for_cts();
}

// initialise the radio hardware
//
bool
radio_initialise(void)
{
/* TODO: check timing */
SDN = 1;
delay_msec(1);
SDN = 0;
delay_msec(6);

wait_for_cts();

cmd_power_up(0x1, 0x0, 30000000);
wait_for_cts();

if (!check_part())
return false;

radio_gpio_init();

return true;
}

Expand Down Expand Up @@ -816,7 +820,7 @@ radio_configure(__pdata uint8_t air_rate)
cmd_fifo_info(0x03);
wait_for_cts();

radio_gpio_init();
radio_set_diversity(DIVERSITY_ENABLED);

return true;
}
Expand Down Expand Up @@ -1002,19 +1006,58 @@ radio_temperature(void)
return 0;
}

/// Turn off radio diversity
///
#define GPIO_DRIVE0 2
#define GPIO_DRIVE1 3
#define GPIO_RX_RAW_DATA 21
#define GPIO_PKT_TRACE 29
#define GPIO_ANT_1_SW 22
#define GPIO_ANT_2_SW 23
#define GPIO_VALID_PREAMBLE 24
#define GPIO_TX_STATE 32
#define GPIO_RX_STATE 33

static void
radio_set_diversity_gpio(enum DIVERSITY_Enum state)
{
if (state != DIVERSITY_ANT2) {
cmd_gpio_pin_cfg(
0x40 | GPIO_ANT_1_SW,
0x40 | GPIO_ANT_2_SW,
0x40 | GPIO_RX_STATE,
0x40 | GPIO_TX_STATE,
39, // nIRQ
0, // SDO
2 << 5
);
} else {
cmd_gpio_pin_cfg(
0x40 | GPIO_ANT_2_SW,
0x40 | GPIO_ANT_1_SW,
0x40 | GPIO_RX_STATE,
0x40 | GPIO_TX_STATE,
39, // nIRQ
0, // SDO
2 << 5
);
}
wait_for_cts();
}

void
radio_set_diversity(enum DIVERSITY_Enum state)
{
switch (state) {
case DIVERSITY_ENABLED:
case DIVERSITY_ANT2:
case DIVERSITY_DISABLED:
case DIVERSITY_ANT1:
default:
break;
}
EX0_SAVE_DISABLE;
/* evaluate strength on both antennas, no bias towards first antenna */
cmd_set_property2(
GROUP_MODEM, 0x48,
0x1, // value for ANT_DIV_MODE
0x8 | (state == DIVERSITY_ENABLED) << 2
);
wait_for_cts();

radio_set_diversity_gpio(state);
diversity_saved = state;
EX0_RESTORE;
}

/*
Expand Down

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