LoRa
来自Jack's Lab
(版本间的差异)
(→TX) |
(→Spreading Factor) |
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第4行: | 第4行: | ||
[[文件:Sx1278-spreading-factor.png]] | [[文件:Sx1278-spreading-factor.png]] | ||
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+ | '''Note:''' | ||
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+ | The Spreading Factor must be known in advance on both transmit and receive sides of the link as different spreading factors are orthogonal to each other | ||
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+ | |||
+ | Spreading Factor 6: | ||
+ | |||
+ | * Set Spreading Factor = 6 in Reg_ModemConfig2 | ||
+ | * The head must be set to Implicit mode | ||
+ | * Set the DetectionOptimize of Reg_LoRaDetectOptimize to value '0b101' | ||
+ | * Write 0x0C in the RegDetectionThreshold | ||
<br> | <br> |
2017年10月11日 (三) 19:15的版本
目录 |
1 Key Concepts
1.1 Spreading Factor
Note:
The Spreading Factor must be known in advance on both transmit and receive sides of the link as different spreading factors are orthogonal to each other
Spreading Factor 6:
- Set Spreading Factor = 6 in Reg_ModemConfig2
- The head must be set to Implicit mode
- Set the DetectionOptimize of Reg_LoRaDetectOptimize to value '0b101'
- Write 0x0C in the RegDetectionThreshold
1.2 Coding Rate
1.3 Signal Bandwidth
2 TX
- Static configuration registers can only be accessed in Sleep, Standby or FSTX mode
- The LoRa FIFO can only be filled in Standby mode
- Data TX is initiated by sending TX mode request
- Upon completion the TxDone interrupt is issued and the radio returns to Standby mode
- Following transmission the radio can be manually placed in Sleep mode or the FIFO refilled for subsequent TX operation
LoRa TX data FIFO filling:
- Set Reg_FifoAddrPtr to Reg_FifoTxBaseAddr
- Write PayloadLength bytes to the FIFO (Reg_Fifo)
Reg_Fifo 是 FIFO 的统一读写口,SPI 读写 Reg_Fifo,就会去 FIFO 内部地址为 Reg_FifoAddrPtr 的位置取放数据
TX_Modem 直接去 FIFO 地址为 Reg_FifoTxBaseAddr 的位置,取 PayloadLength 字节的数据
3 Schematics
http://modtronix.com/prod/imod/inair4/inair4_r1_sch.pdf
4 Chip
4.1 SX1278
- http://www.semtech.com/wireless-rf/rf-transceivers/sx1278/
- http://www.semtech.com/images/datasheet/LoraLowEnergyDesign_STD.pdf
- http://www.semtech.com/images/datasheet/LoraDesignGuide_STD.pdf
- http://www.semtech.com/images/datasheet/AN1200.19_SX127x_RefDesign_STD.pdf
- http://www.semtech.com/images/datasheet/an120014-xo-guidance-lora-modulation.pdf
5 Reference
- http://www.semtech.com/wireless-rf/rf-transceivers/
- http://cpham.perso.univ-pau.fr/LORA/RPIgateway.html