This is an Arduino library for LoRa Communication using the radio transceiver chips SX1262 and SX1268.
Ai-Thinker offers several LoRa modules.
You can get these on AliExpress and eBay.
| Model | Type | Interface/Core | Chip | Frequency | Foot-Pattern | IPEX-Antena | LoRa-WAN |
|---|---|---|---|---|---|---|---|
| Ra-01 | Tranceiver | SPI | SX1278 | 410-525Mhz | SMD16 | No | No |
| Ra-02 | Tranceiver | SPI | SX1278 | 410-525Mhz | SMD16 | Yes | No |
| Ra-01H | Tranceiver | SPI | SX1276 | 803-930Mhz | SMD16 | No | No |
| Ra-01S | Tranceiver | SPI | SX1268 | 410-525Mhz | SMD16 | No | No |
| Ra-01SH | Tranceiver | SPI | SX1262 | 803-930Mhz | SMD16 | Yes | No |
| Ra-01SC | Tranceiver | SPI | LLCC68 | 410-525Mhz | SMD16 | Yes | No |
| Ra-06 | MCU | ARM Cortex M0+ | SX1278 | 410-525Mhz | SMD20 | Yes | No |
| Ra-07 | MCU | ARM Cortex M0+ | ASR6501 | 410-525Mhz | SMD18 | No | Yes |
| Ra-07H | MCU | ARM Cortex M0+ | ASR6501 | 803-930Mhz | SMD18 | No | Yes |
| Ra-08 | MCU | ARM Cortex M4 | ASR6601 | 410-525Mhz | SMD18 | No | Yes |
| Ra-08H | MCU | ARM Cortex M4 | ASR6601 | 803-930Mhz | SMD18 | No | Yes |
LoRa modules with SX1262/1268 have several options.
-
Using TCXO(Temperature-Compensated Crystal Oscillator)
SX1262/1268 can use the TCXO.
If the TCXO is used, the XTB pin is not connected.
However, the 6th pin (DIO3) of the SX1262/1268 can be used to power the TCXO.
Explanation for TXCO and antenna control is here.
Ra-01S / Ra-01SH does not use TCXO. -
Power supply modes
SX1262/1268 has two power supply modes.
One is that only LDO used in all modes.
Another is that DC_DC+LDO used for STBY_XOSC,FS, RX and TX modes.
Explanation for LDO and DCDC selection is here.
Ra-01S / Ra-01SH use only LDO in all modes. -
RF-Switching
In general, use DIO2 to switch the RF-Switch.
However, some tranceiver use an external gpio to switch the RF-Switch.
Ra-01S / Ra-01SH use the SC70-6 integrated load switch to switch between RFO and RFI.
Ra-01S / Ra-01SH use DIO2 to control this.
DIO2 = 1, CTRL = 0, RFC to RF1 Tx Mode.
DIO2 = 0, CTRL = 1, RFC to R21 Rx Mode.
You need to look at the schematic to set these options properly, but it's very esoteric.
The default settings for this library are for Ra-01S / Ra-01SH.
When using other than Ra-01S / Ra-01SH, you need to set them appropriately.
I created this library based on this.
With this library, Ra-01S / Ra-01SH doesn't work.
Ra-01SC uses LLCC68.
Ra-01SC is compatible with Ra-01S.
However, there are the following restrictions:
- BW is either 125KHz, 250KHz or 500Khz.
- When BW is 125KHz, SF is in the range of 5-9.
- When BW is 250KHz, SF is in the range of 5-10.
- When BW is 500KHz, SF is in the range of 5-11.
-
RA-01S
https://docs.ai-thinker.com/_media/lora/docs/ra-01s_specification.pdf -
RA-01SH
https://docs.ai-thinker.com/_media/lora/docs/ra-01sh_specification.pdf -
RA-01SC(Chinese)
https://img.iceasy.com/product/product/files/202108/8a8a8a1a7aec7b55017b2ef70a370953.pdf
RA-0x(SMD16) has the same foot pattern as ESP12.
Therefore, a pitch conversion PCB for ESP12 can be used.
Download this repo as zip. Then in the Arduino IDE go to Sketch->Add library->add .zip library.
| Ra-01S/SH | UNO | MEGA | ESP8266 | |
|---|---|---|---|---|
| VCC | -- | 3.3V(*1) | 3.3V | 3.3V |
| GND | -- | GND | GND | GND |
| SCK | -- | D13(*2) | D52(*2) | IO14 |
| MISO | -- | D12 | D50 | IO12 |
| MOSI | -- | D11(*2) | D51(*2) | IO13 |
| NSS | -- | D5(*2) | D5(*2) | IO2 |
| RST | -- | D6(*2) | D6(*2) | IO0 |
| BUSY | -- | D7(*2) | D7(*2) | IO16 |
| TXEN | -- | N/C | N/C | N/C |
| RXEN | -- | N/C | N/C | N/C |
(*1)
UNO's 3.3V output can only supply 50mA.
In addition, the output current capacity of UNO-compatible devices is smaller than that of official products.
So this module may not work normally when supplied from the on-board 3v3.
(*2)
SX126x is not 5V tolerant.
You need level shift from 5V to 3.3V.
I used this for a level shift.
EBYTE offers several LoRa modules.
You can get these on AliExpress and eBay.
| Model | Interface | Chip | Frequency | Power | Foot-Patten | IPEX-Antena | LoRa-WAN |
|---|---|---|---|---|---|---|---|
| E22-400M22S | SPI | SX1268 | 433/470Mhz | 160mW | Standard | Yes | No |
| E22-400M30S | SPI | SX1268 | 433/470Mhz | 1000mW | Standard | Yes | No |
| E22-400MM22S | SPI | SX1268 | 433/470Mhz | 160mW | Small | No | No |
| E22-900M22S | SPI | SX1262 | 868/915Mhz | 160mW | Standard | Yes | No |
| E22-900M30S | SPI | SX1262 | 868/915Mhz | 1000mW | Standard | Yes | No |
| E22-900MM22S | SPI | SX1262 | 868/915Mhz | 160mW | Small | No | No |
With this change it work.
/*
SX126x lora(5, //Port-Pin Output: SPI select
6, //Port-Pin Output: Reset
7 //Port-Pin Input: Busy
);
int16_t ret = lora.begin(RF_FREQUENCY, //frequency in Hz
TX_OUTPUT_POWER); //tx power in dBm
*/
SX126x lora(5, //Port-Pin Output: SPI select
6, //Port-Pin Output: Reset
7 //Port-Pin Input: Busy
8 //Port-Pin Output: TXEN
9 //Port-Pin Output: RXEN
);
int16_t ret = lora.begin(RF_FREQUENCY, //frequency in Hz
TX_OUTPUT_POWER, //tx power in dBm
3.3, //use TCXO
true); //use TCXO
Two additional wires are required.
| EBYTE | UNO | MEGA | ESP8266 | |
|---|---|---|---|---|
| TXEN | -- | 8(*3) | 8(*3) | D4 |
| RXEN | -- | 9(*3) | 9(*3) | D5 |
(*3)
SX126x is not 5V tolerant.
You need level shift from 5V to 3.3V.
The pitch conversion base is here.
SX1262 and LLCC68 are compatible, but for some reason they don't work.
| Model | Interface | Chip | Frequency | Power | Foot-Patten | IPEX-Antena | LoRa-WAN |
|---|---|---|---|---|---|---|---|
| E220-400M22S | SPI | LLCC68 | 433/470Mhz | 160mW | Standard | Yes | No |
| E220-400M30S | SPI | LLCC68 | 433/470Mhz | 1000mW | Standard | Yes | No |
| E220-900M22S | SPI | LLCC68 | 868/915Mhz | 160mW | Standard | Yes | No |
| E220-900M30S | SPI | LLCC68 | 868/915Mhz | 1000mW | Standard | Yes | No |
This library can communicate with RadioLib.
RadioLib require DIO1 connected in order to works.
// Set frequency: 866Mhz
// Set bandwidth(BW): 125Khz
// Set Spreading Factor(SF): 7
// Set Error Cording Rate(CR): 4/5
// Set SyncWord: 0x1424(Private Network)
// Set Power: 10dBm
// Set Preamble Length: 8
// Configure the radio to NOT use a TCXO controlled by DIO3
// Set regulator mode: DC-DC
int state = radio.begin(866.0, 125.0, 7, 5, RADIOLIB_SX126X_SYNC_WORD_PRIVATE, 10, 8, 0.0, false);
- The SX126x chip implements FSK, but FSK is not supported in this library.
- Interrupts is not supported in this library.
This will be helpful.
$ git clone https://github.com/nopnop2002/Arduino-LoRa-Ra01S
$ cd Arduino-LoRa-Ra01S/example/Ra01S-RX/
$ pio init -b d1_mini
$ cp Ra01S-RX.ino src/
$ vi src/Ra01S-RX.ino
Disable AtMega
Enable ESP8266
$ vi platform.ini
[env:d1_mini]
platform = espressif8266
board = d1_mini
framework = arduino
lib_deps = https://github.com/nopnop2002/Arduino-LoRa-Ra01S --> Add this line
$ pio run -t upload && pio device monitor -b 115200
