Introduction

This training will walk you through setting up the Easy Link Network Processor example, as well as using SmartRF Studio for RF evaluation. When you have completed the training you will be able to set up the TI-RTOS EasyLink AT command Network Processor example to run on supported hardware, e.g. the CC13xx or CC2640R2 LaunchPad.

This training lab is divided into the following tasks:

Task 1: Importing the EasyLink Network Processor Example

Task 2: Using the AT Command Interface to Configure RF Settings

Task 3: Exchanging Data Between Two Devices

Task 4: Exchanging Data Between a Device and SmartRF Studio

Task 5: EasyLink Packet Error Rate (PER) Test

Technical support

For any questions you may have, please have a look at the relevant E2E forums: TI Sub-1 GHz E2E Forum, TI 2.4 GHz Proprietary E2E Forum

Prerequisites

Background

  • Basic knowledge about TI-RTOS and Code Composer Studio
  • Some basic familiarity with embedded programming

Software

In order to start with this excercise you will need to download the correct Software Development Kit (SDK) for your LaunchPad.

For CC13x0:

For CC13x2:

For CC2640R2:

Common software for all devices:

Hardware

  • 2 x CC13xx LaunchPads or 2 x CC2640R2 LaunchPads.

Team Up!

Two LauchPads are required in order to transmit and receive data between them. If in a group, you may work in pairs, and then each student will only need one LaunchPad.

Note

This lab can be performed using either CC1310, CC1350, CC1312, CC1352 or CC2640R2 LaunchPads.
The training material is based on a CC1350 LaunchPad, but for this training the steps and procedures are the same regardless of type of device. If you need to make adjustment based on the device you are using, it will be highlighted during the training.

Group training additional requirements

Make sure to always use your designated frequency, to avoid interfering with other students' operations

Frequency allocation

If you are part of a group training, please ask the instructor for a unique frequency to use during this lab.

For simplicity, it is possible to use a base frequency (2440.0, 915.0, 868.0, 433.0), allocate a running number to each of the students and have each student multiply their number by 100 kHz channel spacing. For example, student #5 would then use 868 + 0.1*5 = 868.5 MHz.

EasyLink API

The RF core has a dedicated driver called the TI-RTOS RF driver. This is used for all interaction with the RF core. The EasyLink API is a simple abstraction layer on top of the RF Driver and is intended as a starting point for customers creating a proprietary protocol or application using the Sub1-GHz or 2.4 GHz frequency band.

EasyLink Examples

The following examples can be found in the resource explorer under the corresponding device SDK. The available examples vary with the device SDK used; see the table below for a summation of the available examples.

Example CC13x0 CC13x2 CC2640R2
rfEasyLinkTx Yes Yes Yes
rfEasyLinkRx Yes Yes Yes
rfEasyLinkEchoTx Yes Yes No
rfEasyLinkEchoRx Yes Yes No
rfEasyLinkNp Yes Yes Yes
rfEasyLinkListenBeforeTalk Yes Yes No
rfWsnConcentrator Yes Yes Yes
rfWsnConcentratorOadServer Yes Yes No
rfWsnNode Yes Yes Yes
rfWsnNodeExtFlashOadClient Yes Yes No
rfWsnNodeIntFlashOadClient Yes No No

OAD = Over the Air Download.

For instructions on using the CC13xx and CC2640R2 MCU SDK examples and the EasyLink API, refer to the CC13xx Prorietary User's Guide.

Note

The EasyLink layer does not support any regional RF conformance such as Listen Before Talk, required for the license-free frequency band. Customers need to add support for the regional conformance features that their product requires under the EasyLink API.

Easylink Alternatives

If you do not wish to use the EasyLink abstraction layer, there is also the option to do simple packet RX/TX using the TI-RTOS RF driver directly. For more info, see SimpleLink Academy lab Proprietary RF - Basic RX and TX.

The API

EasyLink programming is utilized through a set of API function calls, encapsulating the required RF operations.

API

The EasyLink API is documented both online and offline in the Prorietary User's Guide and is briefly presented here for reference:

Generic API function Description
EasyLink_init() Inits and opens the RF driver
EasyLink_transmit() Blocking transmit
EasyLink_transmitAsync() Nonblocking transmit
EasyLink_receive() Blocking receive
EasyLink_receiveAsync() Non-blocking receive
EasyLink_abort() Aborts a non-blocking call
EasyLink_GetIeeeAddr() Gets the IEEE address
EasyLink_EnableRxAddrFilter() Enables/disables RX filtering on the address
EasyLink_SetFreq() Sets the frequency
EasyLink_GetFreq() Gets the frequency
EasyLink_SetRfPwr() Sets the TX power
EasyLink_GetRfPwr() Gets the TX power
EasyLink_getAbsTime() Gets the absolute radio time
EasyLink_setCtrl() Sets advanced configuration options
EasyLink_getCtrl() Gets advanced configuration options

In the EasyLink Network Processor project, the EasyLink API is also exposed via an AT Command Interface such that it can be exercised over serial transport by a host software (running on an PC, MPU or MCU) or manually by using a serial terminal emulator. This manual approach is used and demonstrated in the tasks below.

Task 0: Label your LaunchPads

  1. Label each of your LaunchPads with its XDS Device ID, as described here.

  2. Label one LaunchPad as "A" and the other as "B". These labels will be referred to throughout this lab. It is recommended to use a non-permanent marking for this (e.g. sticky notes), as these labels may only be relevant for this specific lab.

Task 1: Importing the EasyLink Network Processor Example

In this task we will use Code Composer Studio (CCS) to import, build and flash the EasyLink Network Processor example onto the LaunchPad platform.

CCS Alternatives

While the current lab is designed for CCS, it may be useful to note that the various TI-RTOS examples are also compatible with IAR Embedded Workbench ( see TI Processors wiki), with GCC as well as with the Cloud based version of Code Composer Studio.

Import the Example Project

  1. Open CCS 8.2 or later

  2. To open Resource Explorer, click "Browse examples" in the Getting Started pane, or open it from the menu under ViewResource Explorer

    Attention

    Do not open Resource Explorer Classic (if it is an available option). In this lab we will be working with the new Resource Explorer.

  3. If this is the first time running Resource Explorer after installing the SimpleLink SDK, make sure it finds the SDK, and let it import it.

  4. Expand the elements: Software SimpleLink CC13xx SDK - v:x.x.x.xExamplesDevelopment Tools CC13xx LaunchPadEasyLinkrfEasyLinkNpTI-RTOS

    Make sure to import the correct example!

    When browsing the Resource Explorer, make sure to select the SDK that corresponds to the device you are using. This training assumes the CC1350 LaunchPad is used which will be reflected in images and file names.

  5. Select CCS Compiler (i.e. click on CCS Compiler in the folder-tree view on the left). Your view should look similar to this:

  6. Click on Import to IDE icon in top right corner (see image above).

    You have now imported the rfEasyLinkNp example project

    There should now be a new project in the Project Explorer called rfEasyLinkNp_CCxxxx_LAUNCHXL_tirtos_ccs:

    Note

    The TIRTOS kernel is now included as a separate project imported with the example project - In the screen capture above, see the tirtos_builds_CCxxxx_LAUNCHXL_release_ccs project. The TIRTOS kernel project is specific to the board type and compiler and shared by all examples for that Board type / compiler.

Build and flash the Example

  1. Connect one LaunchPad to your PC via USB. This will enumerate two serial COM ports on the PC, one of them will have the word "UART" in its name string - this is referred to as the Application UART.

  2. Connect a PC terminal emulator program (e.g. Tera Term) to the LaunchPad via the Application UART port, using the configuration 115200,8,N,1.

  3. Configure the terminal program to add <LF> character to each incoming and outgoing <CR> character, and disable local echo of outgoing characters

  4. In CCS, Build and download the example by clicking "Debug" (shortcut F11):

  5. Run the example by clicking on the Resume button (F8).

  6. Verify the program operation:

    Watch the terminal program on the PC

    You should now see "EasyLink" and version information being printed to the terminal via UART. The device is now ready to accept AT commands.

  7. Terminate the CCS debug session (by clicking the red square icon)

  8. If working in pairs, or this is already the second LaunchPad that you are programming, skip ahead to Task 2. Otherwise, perform the next steps to program the second LaunchPad.

  9. Disconnect the terminal program from the first LaunchPad

  10. Disconnect the first LaunchPad from the PC

  11. Repeat the procedure above from step 1, using the second LaunchPad this time.

Task 2: Using the AT Command Interface to Configure RF Settings

The AT Command Interface uses ASCII characters, so that a user can easily send and receive the commands through a terminal emulator. Additionally, it makes use of framing characters, to enable a host software to send and receive the AT commands programmatically.

The frame format is shown below:

Start of Frame Command Type Command ID parameters End Of Frame
"AT" "P" or "+" {i} {xxxx} <CR>

<CR> represents Carriage Return, i.e. ASCII character 0x0D. When typing in the commands in a terminal, simply press ENTER to execute.

Avoid using backslash and similar keys as they can be interpreted as command characters.

Keep in mind that the EasyLink API is documented both online and offline in the Prorietary User's Guide. The AT interface documentation can be found inside the README.html file found inside the rfEasyLinkNp example project.

Team work?

If working in pairs, make sure both students use the same RF settings, including the frequency that was allocated to one of you by the instructor.

  1. At this point, you should have a terminal emulator running, already connected to a LaunchPad.

  2. In order to initialize the radio to 2-GFSK 50kbps mode send the following command using the AT interface via the serial port:

    AT+i 0
    

    AT+i – Used to initialize the radio.

    Make sure to select a supported mode

    Depending on the device, different modes are supported. Make sure to select a mode that works for your device. If using the CC2640R2 LaunchPad , you can for example use mode 2, 5 or 6. For this training, it is recommended to use mode 5.

    Arguments of the i/I command

    For CC13xx devices only:

    • 00: 2-GFSK, 50 kbps
    • 01: For 625 bps Long Range Mode
    • 04: For 5kbps SimpleLink Long Range Mode

      For CC2640R2 devices only:

    • 05: For 100kbps 2.4G 2-GFSK Mode
    • 06: For 250kbps 2.4 2-GFKS Mode

      For all devices:

    • 02: For user defined from smartRF_settings.c/h

    Verify the response

    The device shall respond with "OK".

  3. Set the frequency to your (your team's) allocated frequency, by sending the FR command (in the example below, it is used to set the frequency to 871.0MHz)

    ATPFR=871000000
    

    ATPFR: Used to set the communication frequency/channel of the

    radio.

    If you omit this command...

    The default frequency is 868.0 MHz for most examples. Depending on the LaunchPad used, the default center frequency used will be different. For example, the CC2640R2 LaunchPad examples operates at a 2440 MHz center frequency and the CC13xx 433 MHz LaunchPad examples operate at 433 MHz.

  4. Find out what the output power is set to, by sending the following command

    ATPPW?
    

    ATPPW: Used to set/get the radio output power.

    See the response

    The radio shall reply with the configured output power setting, followed by "OK" (without any spaces), e.g. 0013OK.

    Enabling Maximum Transmit Power

    With the default ccfg settings, the Sub-1 GHz transmit power is limited by the DC/DC converter configuration to 12.5 dBm (displayed as 13). See the EasyLink API on how to enable higher transmit power.

    When using CC2640R2, the maximum output power is 5 dBm.

  5. If working in pairs, or you have already completed the above steps for the second LaunchPad, skip ahead to Task 3. Otherwise, perform the next steps:

  6. Connect the second LaunchPad to the PC (leave the first LaunchPad connected)

  7. Open another terminal emulator instance and connect it to the second LaunchPad using its application UART. Use the same UART configuration and terminal configuration as before.

  8. Repeat the procedure starting at step 1 above, this time working with the second LaunchPad.

Task 3: Exchanging Data Between Two Devices

  1. Put the LaunchPad labeled "A" in RX mode:

    AT+RX
    

    AT+RX: Used to set the radio in RX mode.

    Note

    AT+RX initiates reception of a single packet. To receive another packet, issue AT+RX again.

  2. Send some data from the other ("B") LaunchPad:

    AT+TX Hello World!
    

    AT+TX: Used to send data.

    Did it work?

    Look at the terminal of the receiver, and verify you got the text that was sent.

Task 4: Exchanging Data Between a Device and SmartRF Studio

Next we will send packets from a LaunchPad connected to SmartRF Studio to another LaunchPad running the EasyLink NWP (NetWork Processor) example.

  1. As a starting point, you should have LaunchPad "A" connected to a terminal and configured as in Task 2 above (This is probably already the case after completing the tasks above).

  2. Disconnect the terminal emulator from LaunchPad "B" (if currently connected), while keeping this LaunchPad connected to the PC.

  3. Put LaunchPad "A" in RX mode:

    AT+RX
    

    AT+RX: Used to set the radio in RX mode.

  4. Open SmartRF Studio and double-click LaunchPad "B" in the device listing ( identify it by its XDS Device ID), to open up the Device Control Panel. If the required LaunchPad is not shown in the device listing, click on the green arrow next to Refresh list.

  5. In the mode selection window, select Proprietary mode

  6. Update the RF parameters to match the ones you are using on LaunchPad "A", which is running the EasyLink device. Additionally, make sure you adhere to the EasyLink Frame format:

    • Look back to what mode you selected using the "AT+i x" command - double-click the respective configuration option in the Typical Settings pane. If needed, adjust the settings manually to match your device.
    • You also used "ATPFR" to set the frequency. Enter the same frequency in the RF Parameters pane.
    • Enable Address and set it to 00 (which is the default in EasyLink), send Text (ASCII), and do not include a sequence number - see highlighted fields in the following screen capture:

  7. Click on the Start button in the TX tab to send the data.

    Does it work?

    Verify that you received the data on the device running EasyLink NWP ( LaunchPad "A"). Remember that the AT+RX command only receives a single packet. To receive another packet, run the AT+RX command again.

  8. Now do it the other way around: send data from your EasyLink device and receive it using SmartRF Studio. When configuring the SmartRF Studio RX mode, make sure to set it to Text mode, disable sequence number, enable address check, and set the address to 0.

Task 5: EasyLink Packet Error Rate (PER) Test

In this task we will be setting up a PER test between two devices running the EasyLink NWP example.

Supported tests

The EasyLink AT interface supports the following test modes:

  • Carrier Wave

  • Modulated Signal

  • PER TX

  • PER RX

Initialize two NWP setups

  1. As a starting point, you should have the two LaunchPads running the NWP firmware and connected to terminals. If any of the LaunchPads is connected to SmartRF Studio, close SmartRF Studio and reset the LaunchPad (e.g. by pressing its reset button), to restart the firmware execution.

  2. Initialise both devices to use 50kbps 2-GFSK mode:

    AT+i 0
    

    AT+i: Used to initialize the radio.

  3. If in a group, make sure to use your allocated frequency on both LaunchPads. For example:

    ATPFR=871000000
    

    ATPFR: Used to set the communication frequency/channel of the

    radio.

  4. The number of packets to process during the test is determined by the PP parameter. If this parameter is set to 0, then the test will run indefinitely.

    Configure the test on both LaunchPads to run for 100 packets:

    ATPPP=100
    

    ATPPP: Read/Write number of PER TX/RX packets

Check yourself

Make sure you entered the commands above on both of the LaunchPads.

PER Receiver

  1. Select one of the LaunchPads (e.g. "A") to be the receiver. Start a PER RX test (test mode 4), by using:

    ATPTM=4
    

    ATPTM: Read/Write test mode.

    Ready for RX

    The device enters RX and accepts 100 packets.

PER Transmitter

  1. Start a PER TX test (test mode 3) on the other LaunchPad (e.g. "B"):

    ATPTM=3
    

    ATPTM: Read/Write test mode.

    Test is running

    The device starts TX and transmits 100 packets.

Interpreting the results

While the test is running, the TX device's terminal should look like this:

TPER: 00
TPER: 01
TPER: 02
...

and the RX device should show lines similar to these:

RPER: 00, 0001, 0000, -31
RPER: 01, 0002, 0000, -31
RPER: 02, 0003, 0000, -31
...

The columns reported by the RX device correspond to:

RPER: Sequence Number, Pass Count, Fail Count, RSSI

The sequence number is sent from the TX PER device, and is expected to increment by 1 for each packet. Pass Count increments every time a correct packet is received. Fail Count increments every time an incorrect packet is received.

Once the test is finished, you should see the response below on both the TX and RX devices:

Done OK

Make some practical measurements!

Do some range testing: move around in the building with one of the devices, repeat the PER test from different locations and compare the results.

Bonus Tasks

The instructions of the bonus tasks are much less detailed than those of the main tasks above. To complete the bonus tasks, you may need to refer to the SDK documentation.

The bonus tasks can be done in any order.

Bonus Task 6: Long Range Mode PHY

Change the PHY settings to use the Long Range Mode (LRM), then do some more PER testing. Does the range improve?

LRM is only supported by CC13xx devices

If using the CC2640R2 LaunchPad for this training, skip this section.

Bonus Task 7: Explore the AT Command Interface

Explore what else you can realize by using the EasyLink AT commands API. Remember, the EasyLink API is documented in the Prorietary User's Guide and the AT commands here.

References

CC13xx Overview – Available here

CC2640R2 Overview – Available here

CC13x0 and CC2640R2 Technical Reference Manual – Available here

CC13x2 Technical Reference Manual – Available [here][Technical Reference Manual CC13x2]

EasyLink API: Available in the Prorietary User's Guide

[Technical Reference Manual CC13x2]: http://www.ti.com/lit/swcu185erence Manual CC13x2]: http://www.ti.com/lit/swcu185

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