wayne roberts / SX127x

Driver library for SX1272/SX1276 transceivers

Dependents:   LORA_RX LORA_TX WindConcentrator hid_test ... more

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Driver library for SX1272 and SX1276 radio transceivers.

This device uses CSS modulation to provide much improved link budget. The RF hardware is same as in FSK devices, just with added LoRa spread-spectrum modem.

This library provides functions to configure radio chip and transmit & receive packets.

Using This Library

Library function service_radio() must be called continuously from main loop, to service interrupts from radio.

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Board Specific implementation

FunctionPointer for rf_switch callback allows the program to implement control of RF switch unique to their board. Example options are:

  • SKY13373 for external power amplifier implementation. Requires two DigitalOut pins.
  • SKY13350 using PA_BOOST. requires two DigitalOut pins.
  • PE4259-63: controlled directly by radio chip, no software function needed. However, in the case of SX1276MB1xAS, the RXTX pin on IO2 should be driven by this callback function when R16 is installed (without R15) on this shield board.

Some configurations may need to force the use of RFO or PA_BOOST, or a board could offer both options. The rf_switch function pointer callback should support the implementation choice on the board.

further reading

Diff: sx127x_lora.h

Revision:
11:4210303ac88d
Parent:
10:7382c260c4b1
Child:
12:bda42457c34a
--- a/sx127x_lora.h	Fri Feb 27 22:50:18 2015 +0000
+++ b/sx127x_lora.h	Tue Mar 17 20:06:45 2015 +0000
@@ -40,7 +40,10 @@
 #define REG_LR_TEST31                               0x31    // if_freq_auto, ...
 #define REG_LR_TEST32                               0x32    // 
 #define REG_LR_TEST33                               0x33
+#define REG_LR_CAD_PEAK_TO_NOISE_RATIO              0x34
+#define REG_LR_CAD_MIN_PEAK                         0x35
 #define REG_LR_DETECTION_THRESHOLD                  0x37
+#define REG_LR_SYNC_BYTE                            0x39    // default 0x12 (value of 0x21 will isolate network)
 
 typedef union {
     struct {    // sx127x register 0x12