SEMTECH SX1261 Long Range Low Power Sub-GHz Transceiver User Guide

SEMTECH SX1261 Long Range Low Power Sub-GHz Transceiver

Contents of Delivery

The Development Kit for a SX1261 or SX1262 transceiver is delivered with the following contents:

• 2 SX126xMB1xAS RF modules including a microcontroller ST Nucleo MBED board and a touch screen
• 2 connection cables Mini-USB / USB
• 2 868/915 MHz antennas
• 2 Mini-USB cables
• 2 touch screen styluses
• 1 Read-Me Note

Before powering the kit, make sure to assemble the three parts shown in the image below:

When you assemble the parts, make sure that they are correctly oriented, as shown below:

First Use

Connect the SX1261/SX1262 Development Kit

1. Plug the mini-USB / USB cable into the mini-USB socket of the SX1261/SX1262 Development Kit
2. Plug the mini-USB / USB cable into the USB socket of your PC

The SX1261/SX1262 Development Kit will power on and connect to your PC. The type of device (SX1261 or SX1262) is automatically detected by the kit.

Welcome Display

The welcome screen with the top menu is visible upon power-on. You can access the following test modes:

• DEMO Ping Pong
  This performs a bidirectional range test between a pair of radio units.

• DEMO PER
  This performs a unidirectional packet error rate test between user-defined Master and Slave units.

Additionally, you can access the Radio Test Modes , which provide access to the basic operating modes of the radio. The Radio Settings allow you to modify the communication and modem settings used in the demos.
The Utilities menu provides information about the peripherals and version of the installed firmware.

How to Navigate with the Touch Screen

On the touch screen of the kit the following conventions are adopted:

• Menus, functions and configuration of settings are indicated in
• Data that cannot be modified is indicated in
• Result data from tests are indicated in

Check and Upload the Firmware File

Before using the SX1261/SX1262 Development Kit, make sure to have the latest firmware:

• Go to the Utilities section 7
• Check the Firmware Version
• If it is not the latest version, download the firmware from www.semtech.com and save it to your PC
  The firmware can then be uploaded to the SX1261/SX1262 Development Kit.

To upload the firmware file:

• Connect the SX1261/SX1262 Development Kit as explained in Section 2
• Allow your computer to display the kit as an extra device
• Drag and drop the .bin file that has been provided to you or that has been downloaded from the Semtech website
• The kit will initialize and eventually ask you to calibrate the screen, simply follow the on-screen instructions

Ping Pong Demo

A Ping Pong Test is a bidirectional test between a pair of SX1261/SX1262 kits. One kit needs to be configured as the Ping Pong Master and the other kit as the Ping Pong Slave. Communication is initiated by the Master whose packet is received by the Slave from which the PER may be calculated.
In response to this packet the Slave sends an acknowledgement, which also contains statistical information about the link calculated by the Slave. The Master, upon receiving this response, will then display both the PER for the Master to Slave and the Slave to Master packet exchanges.

Press on Demo Ping Pong from the Welcome Display to access this test. You can change the radio settings from this menu:

• Press SETTINGS to adjust the same radio settings on the Master and the Slave units. See Section 6 for more details on the radio settings.

Before starting the test:

• Place the Slave unit into the desired position
• Place the Master unit into the desired position

Press SLAVE to toggle a unit to MASTER and vice-versa

To start the Ping Pong test:

Press START first on the Slave unit then on the Master Unit

• Both units will exchange data until you press STOP on either unit.
  The reception and transmission of data are indicated by LEDs on each unit.

• The result of the test is displayed on the screen of the Master unit:

  • Rx OK: number of packets completely received
  • Rx KO: number of packets not completely received
  • Rx PSR: Percentage Packet Success Rate for the last packet exchange
  • Rx PER: Percentage Packet Error Rate for the last packet exchange
  • Last RSSI: Received Signal Strength Indication [dBm]
  • Last SNR: Signal to Noise Ratio for the last packet exchange [dB]

PER Demo

A Packet Error Rate (PER) test is a unidirectional test where one kit is configured as a Master and the other as a Slave. In this case the Master will assume the role of transmitter and the Slave that of receiver. The aggregate PER of the packets received by the Slave, expressed as a percentage, is calculated and displayed on the receiver (Slave). Given that this is a unidirectional test, the packet error rate is not displayed on the transmitter (Master).

Press on Demo PER from the Welcome Display to access this test. You can change the radio settings from this menu:

• Press SETTINGS to adjust the same radio settings on the Master and the Slave units. See Section 6 for more details on the radio settings.

Before starting the test:

• Place the Slave unit into the desired position
• Place the Master unit into the desired position

Press SLAVE to toggle the unit to MASTER and vice-versa

To start the PER test:

Press START first on the Slave unit then on the Master Unit

• Both units will exchange data until you press STOP on either unit.
  The reception and transmission of data are indicated by LEDs on each unit.

• The result of the Demo is displayed on the screen of the Slave unit:

  • Rx OK: number of packets completely received
  • Rx KO: number of packets not completely received
  • Rx PSR: Percentage Packet Success Rate for the last packet exchange
  • Rx PER: Percentage Packet Error Rate for the last packet exchange
  • Last RSSI: Received Signal Strength Indication [dBm]
  • Last SNR: Signal to Noise Ratio for the last packet exchange [dB]

Radio Test Modes

The Radio Test Modes menu allows you to select certain preset test modes. These test modes permit the test of consumption of the radio in the respective modes, additionally that can be of use to test the specification claims of the datasheet or various modem performances without the need to create custom firmware.

Radio Settings

The radio settings available depend upon the modulation, denoted Mod in the sub-menu Radio Settings. For each modem, you can modify the modulation and power parameters. Registered settings are proper to each modulation.

LORA Modulation

The radio settings available for LORA modulation are:

• Frequency (Freq) as described in Section 6.3
• Payload (PL): the size of the payload between 1 and 64 bytes
• Transmission Power (Tx Pow): in steps of 1 dBm
  • from -17 dBm to +15 dBm for the SX1261
  • from -10 dBm to +22 dBm for the SX1262
• Param 1: Spreading Factor between SF5 and SF12
• Param 2: BandWidth (BW) from 7 kHz to 500 kHz
• Param 3 : Coding Rate (CR) of the Forward Error Correction applied to the packet of either CR 4/5, 4/6, 4/7 or 4/8
• Param 4: Packet type of either Variable length or Fixed length

GFSK Modulation

The radio settings available for GFSK modulation are:

• Frequency (Freq) as described in Section 6.3

• Payload (PL): size of the payload between 1 and 64 bytes

• Transmission Power (Tx Pow): in steps of 1 dBm

  • from -17 dBm to +15 dBm for the SX1261
  • from -10 dBm to +22 dBm for the SX1262

• Param 1: Bitrate from 0.1 kbps to250 kbps

• Param 2: Frequency deviation (Fd) between 5 and 150 kHz.
  This must be set realistically in accordance with the bitrate

• Param 3: Tx Modulation Filtering (Gaussian, RC, RRC) with BT from 0.3 to 1

• Payload: BandWidth (BW) from 4.8 kHz to 467 kHz

Note:
Certain settings will appear in red if they are not compatible and cannot be handled by the radio. Refer to the SX1261/2 Data Sheet to see the relationship details between bitrate, frequency deviation and bandwidth.

Frequency Setting

In this menu you can set the frequency for each modulation:

• Select the frequency Step that you wish to tune: from 1 Hz to 10 MHz
• With – and + change the value of the step of your tuned frequency
• The resulting frequency in displayed in Freq
• Additionally you can select one of the three Preset frequencies by simply pressing the desired frequency value.

Utilities

In this menu you can reset the SX1261/SX1262 Development Kit to its factory settings:

Press on Fact. Reset

The Utilities section is also useful to check the Firmware Version You can modify:

• the RxBoost mode: On (True) or Off (False)
• the power regulation mode (DC Reg): either DCDC or LDO
• the Packets limit: Infinite, 100, 200, 500 or 1000

Revision History

illustrations

Update of the LoRA and GFSK Modulation settings

Important Notice

Information relating to this product and the application or design described herein is believed to be reliable, however such information is provided as a guide only and Semtech assumes no liability for any errors in this document, or for the application or design described herein. Semtech reserves the right to make changes to the product or this document at any time without notice. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. Semtech warrants performance of its products to the specifications applicable at the time of sale, and all sales are made in accordance with Semtech’s standard terms and conditions of sale.

SEMTECH PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS, OR IN NUCLEAR APPLICATIONS IN WHICH THE FAILURE COULD BE REASONABLY EXPECTED TO RESULT IN PERSONAL INJURY, LOSS OF LIFE OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. INCLUSION OF SEMTECH PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE UNDERTAKEN SOLELY AT THE CUSTOMER’S OWN RISK. Should a customer purchase or use Semtech products for any such unauthorized application, the customer shall indemnify and hold Semtech and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs damages and attorney fees which could arise.

The Semtech name and logo are registered trademarks of the Semtech Corporation. All other trademarks and trade names mentioned may be marks and names of Semtech or their respective companies. Semtech reserves the right to make changes to, or discontinue any products described in this document without further notice. Semtech makes no warranty, representation or guarantee, express or implied, regarding the suitability of its products for any particular purpose. All rights reserved.
© Semtech 2018

Contact Information

Semtech Corporation
Wireless & Sensing Products
200 Flynn Road, Camarillo, CA 93012
E-mail: [email protected]
Phone: 805-498-2111, Fax: 805-498-3804 www.semtech.com

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