16 februarie 2018

APRS via LoRa - Links

Cateva instrumente utile pentru LoRa.
-O librarie simplificata pentru Semtech SX127x: https://goo.gl/IeEiC1 Spre deosebire de librariile RadioHead, asta este mai versatila
-O librarie pentru conversia in BAse64: https://github.com/boseji/rBASE64


10 februarie 2018

CSR8635 Bluetooth Audio Module

I put here the informations about the pinouts of the CSR8635 BT audio module because it's hard to get it and I need it at different moments.


The CSR8635 QFN  is a single-chip Bluetooth 4.0  audio ROM device which targets mid-range stereo speakers and headsets.

It was launched by Cambridge Science Park but later on the company was aquired by Qualcomm.




05 februarie 2018

APRS via LoRa III

Se punea problema de a modifica valorile interfetei radio cu valori "custom" folosind libraria RadioMaster:

Solutia:

  const RH_RF95::ModemConfig custom1 =  { 
            RH_RF95_BW_20_8KHZ | RH_RF95_CODING_RATE_4_5,
            RH_RF95_SPREADING_FACTOR_256CPS 
            };
            
  rf95.setModemRegisters(&custom1);

01 februarie 2018

APRS via LoRa II

Am finalizat partea de baliza si partea de receptie si afisare a pozitiei relative (la Target Call).

O baliza RAW este de forma:
$LRPRS,YO3HJV-15,01,02,2018,12,03,56,44.423229,26.111504,3100,29,97390000,415 *

Unitatea de receptie furnizeaza pe serial info de forma:

RX Packet String is : 
$LRPRS,YO3HJV-15,01,02,2018,12,03,56,44.423229,26.111504,3100,29,97390000,415 *

Last Packet RSSI = -40

Preamble = $LRPRS
Target Callsign = YO3HJV-15
Last RX Date = 01/02/2018
Last RX Time: 12:03:56
Last Received Lat = 44.423225
         GPS  Lat = 44.423149
Last Received Long = 26.111503
         GPS  Long = 26.111181
Last Distance to Call m: 27.18  m
Last Distance to Call Km: 0.03  Km
Last Course to Call: [ENE]
70.00  degrees
Last Known Altitude = 31.00
Last Known Speed = 0.3
Last Known Course = 97.39
Battery = 4.15

Location: 44.423145,26.111177  Date/Time: 1/2/2018 10:04:02.00
Location: 44.423145,26.111177  Date/Time: 1/2/2018 10:04:02.00
Location: 44.423149,26.111175  Date/Time: 1/2/2018 10:04:03.00
Location: 44.423149,26.111175  Date/Time: 1/2/2018 10:04:03.00


In partea de inceput este sinteza informatiilor obtinute din primirea unui packet $LRPRS comparate cu informatia de la GPS-ul receptorului.
In partea de jos este un flow continuu de date de la GPS-ul receptorului.

La receptie, se verifica preambulul apoi se procedeaza la extragerea informatiei din sirul CSV.

-$LRPRS- pachet de pozitie
-$LRMSG-pachet cu mesaj
-$LRTLM-pachet exclusiv cu telemetrie


Variantele de modulatie LoRa:

                 rf95.setModemConfig(RH_RF95::Bw125Cr45Sf128);    ///< Bw = 125 kHz, Cr = 4/5, Sf = 128chips/symbol, CRC on. Default medium range
                      // rf95.setModemConfig(RH_RF95::Bw500Cr45Sf128);     ///< Bw = 500 kHz, Cr = 4/5, Sf = 128chips/symbol, CRC on. Fast+short range
                      //  rf95.setModemConfig(RH_RF95::Bw31_25Cr48Sf512);   ///< Bw = 31.25 kHz, Cr = 4/8, Sf = 512chips/symbol, CRC on. Slow+long range

                      //  rf95.setModemConfig(RH_RF95::Bw125Cr48Sf4096);    ///< Bw = 125 kHz, Cr = 4/8, Sf = 4096chips/symbol, CRC on. Slow+long range









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