jLinkexe driver for nodejs

Usage no npm install needed!

<script type="module">
  import connectedyardNodeJlink from 'https://cdn.skypack.dev/@connectedyard/node-jlink';



A NodeJS alternative to nrfjprog

This is a NodeJS driver for the Segger JLink command line tool, jlinkexe, including conveniences found in nrfjprog (Nordic's commandline tool for the NRF series of micro-controllers).

Calls the jlinkexe cli tool for maximum compatibility. Tested on Windows, MacOS and Raspberry Pi.

Getting Started

First, install the nRF Command line Tools, including the jlink cli, Jlinkexe

Then install node-jlink

npm install -g @connectedyard/node-jlink

Test you installation

node-jlink -t

Command line Usage

Usage: node-jlink [options] <commands>

All args after options will be sent to the jlink exe as commands, followed by exit

Module Usage

All commands return promises.

var jlink = require("node-jlink");
jlink.reset();              // resets the device attached to the jlink programmer

var readMyMemCommands = ["h", "mem 0x10001004, 0x20"];
jlink.executeCommands( readMyMemCommands )
    .then( function( results ){
        console.log( result.stdout );

nrfjprog Commands

The following nrfjprog commands are implemented as follows.

These commands return a Promise, resolve( true ) on success, reject( error ) on failure.

jlink.reset();                      // nrfjprog --reset
jlink.pinReset();                   // nrfjprog --pinreset
jlink.eraseAll();                   // nrfjprog --eraseAll
jlink.program( firmwareFilePath );  // nrfjprog --program <firmwareFilePath>

Reading Flash Memory

Flash memory is returned in a buffer.

jlink.readmem( address, numBytes)  // nrfjprog --memrd <address> --w 32 --n <numBytes>
.then( function( buffer ){
.catch( function( error ){

Executing Arbitrary JLinkEXE Scripts

Arbitrary JLinkEXE scripts can be executed by passing an array of commands into jlink.executeCommands( commands ). An Promise is returned, and on resolve the Result be as follows:

     stdout: String, captured from jlinkexe stdout stream, or empty string
     stderr: String, captured from jlinkexe stdout stream, or empty string
     code: Integer, captured from jlinkexe exit code, or 0
     error: Error, from jlinkexe or internal error, or null

A complete list of JLinkEXE commands are available at https://www.segger.com/admin/uploads/productDocs/UM08001_JLink.pdf


By default, the JLinkEXE command is expected to be found on the path as jlinkexe. The default commandline options to jlinkexe are "-device nrf51822 -if swd -speed 4000". These options will be sent with every command unless options are passed to executeCommands

To change these values, set jlink.JLinkExe and jlink.JLinkExeOptions.

To test your executable path, call jlink.isJLinkEXEInstalled() or run

node-jlink -t