wayne roberts
Driver library for SX1272/SX1276 transceivers
Dependents: LORA_RX LORA_TX WindConcentrator hid_test ... more
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.
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
- LoRa modulation basics (dropbox PDF)
- OpenLoRa forum
Diff: sx127x_lora.h
- Revision:
- 18:0ecb6adb7c0b
- Parent:
- 17:59279bc8cdab
- Child:
- 19:1ee6ef1ab73f
--- a/sx127x_lora.h Wed May 27 22:42:30 2015 +0000
+++ b/sx127x_lora.h Tue Jun 02 01:25:47 2015 +0000
@@ -42,8 +42,10 @@
#define REG_LR_TEST33 0x33 // invert IQ
#define REG_LR_CAD_PEAK_TO_NOISE_RATIO 0x34
#define REG_LR_CAD_MIN_PEAK 0x35
+#define REG_LR_SX1276_AUTO_DRIFT 0x36
#define REG_LR_DETECTION_THRESHOLD 0x37
#define REG_LR_SYNC_BYTE 0x39 // default 0x12 (value of 0x21 will isolate network)
+#define REG_LR_GAIN_DRIFT 0x3a
#define REG_LR_DRIFT_INVERT 0x3b
typedef union {
@@ -151,6 +153,23 @@
} RegTest33_t;
typedef union {
+ struct { // sx1276 register 0x36
+ uint8_t freq_to_time_drift_auto : 1; // 0 manual control of 0x3a register
+ uint8_t sd_max_freq_deviation_auto : 1; // 1 manual control of 0x3b[3:1]
+ uint8_t reserved : 6; //
+ } bits;
+ uint8_t octet;
+} RegAutoDrift_t;
+
+typedef union {
+ struct { // sx127x register 0x3a
+ uint8_t freq_to_time_drift : 6; // 0,1,2,3,4,5 manual control of 0x3a register
+ uint8_t preamble_timing_gain : 1; // 6,7
+ } bits;
+ uint8_t octet;
+} RegGainDrift_t;
+
+typedef union {
struct { // sx127x register 0x3b
uint8_t coarse_sync : 1; // 0 must be set to 1
uint8_t fine_sync : 1; // 1 must be clr to 0