diff options
Diffstat (limited to 'src/drivers/ao_cc1120.c')
| -rw-r--r-- | src/drivers/ao_cc1120.c | 69 |
1 files changed, 56 insertions, 13 deletions
diff --git a/src/drivers/ao_cc1120.c b/src/drivers/ao_cc1120.c index 1b907940..3ea8b704 100644 --- a/src/drivers/ao_cc1120.c +++ b/src/drivers/ao_cc1120.c @@ -290,15 +290,32 @@ ao_radio_idle(void) } /* - * Packet deviation is 20.5kHz + * Packet deviation * * fdev = fosc >> 24 * (256 + dev_m) << dev_e * + * Deviation for 38400 baud should be 20.5kHz: + * * 32e6Hz / (2 ** 24) * (256 + 80) * (2 ** 5) = 20508Hz + * + * Deviation for 9600 baud should be 5.125kHz: + * + * 32e6Hz / (2 ** 24) * (256 + 80) * (2 ** 3) = 5127Hz + * + * Deviation for 2400 baud should be 1.28125kHz, but cc1111 and + * cc115l can't do that, so we'll use 1.5kHz instead: + * + * 32e6Hz / (2 ** 24) * (256 + 137) * (2 ** 1) = 1499Hz */ -#define PACKET_DEV_E 5 -#define PACKET_DEV_M 80 +#define PACKET_DEV_M_384 80 +#define PACKET_DEV_E_384 5 + +#define PACKET_DEV_M_96 80 +#define PACKET_DEV_E_96 3 + +#define PACKET_DEV_M_24 137 +#define PACKET_DEV_E_24 1 /* * For our packet data @@ -307,41 +324,55 @@ ao_radio_idle(void) * Rdata = -------------------------------------- * fosc * 2 ** 39 * + * Given the bit period of the baseband, T, the bandwidth of the + * baseband signal is B = 1/(2T). The overall bandwidth of the + * modulated signal is then Channel bandwidth = 2Δf + 2B. + * + * 38400 -- 2 * 20500 + 38400 = 79.4 kHz + * 9600 -- 2 * 5.125 + 9600 = 19.9 kHz + * 2400 -- 2 * 1.5 + 2400 = 5.4 khz + * * Symbol rate 38400 Baud: * * DATARATE_M = 239914 * DATARATE_E = 9 - * CHANBW = 74.42 (round to 100) + * CHANBW = 79.4 (round to 100) * * Symbol rate 9600 Baud: * * DATARATE_M = 239914 * DATARATE_E = 7 - * CHANBW = 58.58 (round to 62.5) + * CHANBW = 19.9 (round to 20) * * Symbol rate 2400 Baud: * * DATARATE_M = 239914 * DATARATE_E = 5 - * CHANBW = 47.61 (round to 50) + * CHANBW = 5.0 (round to 8.0) */ #define PACKET_DRATE_M 239914 #define PACKET_DRATE_E_384 9 -#define PACKET_CHAN_BW_384 0x02 /* 200 / 2 = 100 */ + +/* 200 / 2 = 100 */ +#define PACKET_CHAN_BW_384 ((0 << CC1120_CHAN_BW_CHFILT_BYPASS) | \ + (CC1120_CHAN_BW_ADC_CIC_DECFACT_20 << CC1120_CHAN_BW_ADC_CIC_DECFACT) | \ + (2 << CC1120_CHAN_BW_BB_CIC_DECFACT)) #define PACKET_DRATE_E_96 7 -#define PACKET_CHAN_BW_96 0x42 /* 125 / 2 = 62.5 */ +/* 200 / 10 = 20 */ +#define PACKET_CHAN_BW_96 ((0 << CC1120_CHAN_BW_CHFILT_BYPASS) | \ + (CC1120_CHAN_BW_ADC_CIC_DECFACT_20 << CC1120_CHAN_BW_ADC_CIC_DECFACT) | \ + (10 << CC1120_CHAN_BW_BB_CIC_DECFACT)) #define PACKET_DRATE_E_24 5 -#define PACKET_CHAN_BW_24 0x04 /* 200 / 4 = 50 */ +/* 200 / 25 = 8 */ +#define PACKET_CHAN_BW_24 ((0 << CC1120_CHAN_BW_CHFILT_BYPASS) | \ + (CC1120_CHAN_BW_ADC_CIC_DECFACT_20 << CC1120_CHAN_BW_ADC_CIC_DECFACT) | \ + (25 << CC1120_CHAN_BW_BB_CIC_DECFACT)) static const uint16_t packet_setup[] = { - CC1120_DEVIATION_M, PACKET_DEV_M, - CC1120_MODCFG_DEV_E, ((CC1120_MODCFG_DEV_E_MODEM_MODE_NORMAL << CC1120_MODCFG_DEV_E_MODEM_MODE) | - (CC1120_MODCFG_DEV_E_MOD_FORMAT_2_GFSK << CC1120_MODCFG_DEV_E_MOD_FORMAT) | - (PACKET_DEV_E << CC1120_MODCFG_DEV_E_DEV_E)), CC1120_DRATE1, ((PACKET_DRATE_M >> 8) & 0xff), CC1120_DRATE0, ((PACKET_DRATE_M >> 0) & 0xff), CC1120_PKT_CFG2, ((CC1120_PKT_CFG2_CCA_MODE_ALWAYS_CLEAR << CC1120_PKT_CFG2_CCA_MODE) | @@ -361,6 +392,10 @@ static const uint16_t packet_setup[] = { }; static const uint16_t packet_setup_384[] = { + CC1120_DEVIATION_M, PACKET_DEV_M_384, + CC1120_MODCFG_DEV_E, ((CC1120_MODCFG_DEV_E_MODEM_MODE_NORMAL << CC1120_MODCFG_DEV_E_MODEM_MODE) | + (CC1120_MODCFG_DEV_E_MOD_FORMAT_2_GFSK << CC1120_MODCFG_DEV_E_MOD_FORMAT) | + (PACKET_DEV_E_384 << CC1120_MODCFG_DEV_E_DEV_E)), CC1120_DRATE2, ((PACKET_DRATE_E_384 << CC1120_DRATE2_DATARATE_E) | (((PACKET_DRATE_M >> 16) & CC1120_DRATE2_DATARATE_M_19_16_MASK) << CC1120_DRATE2_DATARATE_M_19_16)), CC1120_CHAN_BW, PACKET_CHAN_BW_384, @@ -368,6 +403,10 @@ static const uint16_t packet_setup_384[] = { }; static const uint16_t packet_setup_96[] = { + CC1120_DEVIATION_M, PACKET_DEV_M_96, + CC1120_MODCFG_DEV_E, ((CC1120_MODCFG_DEV_E_MODEM_MODE_NORMAL << CC1120_MODCFG_DEV_E_MODEM_MODE) | + (CC1120_MODCFG_DEV_E_MOD_FORMAT_2_GFSK << CC1120_MODCFG_DEV_E_MOD_FORMAT) | + (PACKET_DEV_E_96 << CC1120_MODCFG_DEV_E_DEV_E)), CC1120_DRATE2, ((PACKET_DRATE_E_96 << CC1120_DRATE2_DATARATE_E) | (((PACKET_DRATE_M >> 16) & CC1120_DRATE2_DATARATE_M_19_16_MASK) << CC1120_DRATE2_DATARATE_M_19_16)), CC1120_CHAN_BW, PACKET_CHAN_BW_96, @@ -375,6 +414,10 @@ static const uint16_t packet_setup_96[] = { }; static const uint16_t packet_setup_24[] = { + CC1120_DEVIATION_M, PACKET_DEV_M_24, + CC1120_MODCFG_DEV_E, ((CC1120_MODCFG_DEV_E_MODEM_MODE_NORMAL << CC1120_MODCFG_DEV_E_MODEM_MODE) | + (CC1120_MODCFG_DEV_E_MOD_FORMAT_2_GFSK << CC1120_MODCFG_DEV_E_MOD_FORMAT) | + (PACKET_DEV_E_24 << CC1120_MODCFG_DEV_E_DEV_E)), CC1120_DRATE2, ((PACKET_DRATE_E_24 << CC1120_DRATE2_DATARATE_E) | (((PACKET_DRATE_M >> 16) & CC1120_DRATE2_DATARATE_M_19_16_MASK) << CC1120_DRATE2_DATARATE_M_19_16)), CC1120_CHAN_BW, PACKET_CHAN_BW_24, |