AWS Lambda error: HTTP 502 ‘Execution failed due to configuration error: Malformed Lambda proxy response’

Calling an AWS Lambda via API Gateway with the Lambda Proxy Integration option, you might see an HTTP 502 response and this message:

Execution failed due to configuration error: Malformed Lambda proxy response"

Wed May 30 05:00:41 UTC 2018 : Execution failed due to configuration error: Malformed Lambda proxy response
Wed May 30 05:00:41 UTC 2018 : Method completed with status: 502

This is a rather cryptic message, but  it’s saying is the response is not in the expected format.

Per this doc, the expected response should be in this format:

    "isBase64Encoded": true|false,
    "statusCode": httpStatusCode,
    "headers": { "headerName": "headerValue", ... },
    "body": "..."

Homebrew contest 1st place: Packet Radio Go-Kit with node.js Packet to Twitter bridge

Super excited (and rather surprised!) to win the 1st place prize in the Homebrew Contest at this month’s River City Amateur Radio Communications Society club meeting last night!

My entry was something I’ve been working on over the past few months on and off to get ready in time for this month’s contest. There were two parts to my entry:

1. A self-contained, portable 2m Packet Radio Go-Kit. I put this together using:

  • 10″ waterproof gear case (from MCM)
  • 2m HT radio
  • Raspberry Pi 3
  • 7″ touchscreen
  • a TNC-PI packet add-on board for the Pi, from Coastal Chipworks (which I assembled as a kit)
  • ax25 apps (for axlisten and axcall)

2. A Packet Radio to Twitter bridge (implemented using JavaScript on node.js). While the goals and benefits of a portable Packet radio kit are somewhat more obvious, writing an app that receives Packet Radio transmissions and then retransmits them as Tweets on Twitter doesn’t have many practical applications. The main motivation for this part of the project was that I thought it would be an interesting blend of old tech and new tech. The popularity of Packet Radio declined with the arrival of easy access dial-up information services and BBSes in the 80s and then access to the internet in the early 90s, so linking the two together seemed an interesting idea. Plus, it’s an interesting stepping stone and talking point from common-place tech used on our wireless devices today, with data communications enabled via Amateur Radio.

I put together a number of articles as I was assembling my project and working on the Packet to Twitter interface. If you’d like to read more, here’s links to my previous posts:

Updating/installing node.js on the Raspberry Pi

The latest versions of Raspbian (e.g. Jessie) come with an older version of node.js preinstalled. If you search around for how to install node.js on the Pi you’ll find a number of different approaches, as it seems there’s not an official ARM compiled version of the latest releases in the Debian repos.

This approach provided by this project has later versions compiled for ARM. Follow the instructions on their site to download and install from the .deb file.

Before you start, if you already have an older version installed (check ‘node -v’), uninstall it first. The version I had on my fresh Jessie install was from nodejs-legacy, so ‘sudo apt-get remove nodejs-legacy’ did the trick.

Amateur Radio homebrew: Raspberry Pi + Packet Radio + social networking integration

I’m putting something together for our River City Amateur Radio Comms Society homebrew show n tell later this year. Here’s my ingredients so far:

I’m thinking of building a bridge between Amateur Radio Packet and social networking, like Twitter.

So far I’ve roughed out node.js to Twitter integration using node-oauth, and I I’ve put together a simple prototype using the node-ax25 library to connect to the KISS virtual TNC on Direwolf. It receives packets and writes callsigns and messages to the console.

Right now I’m testing this on a PC running Debian, with a Rigblaster Plug n Play connected to an Icom 880h. Later when my TNC-Pi arrives I’ll migrate this to the Pi.

So far using the node-ax25 library looks pretty easy. Here’s some code so far to dump received callsigns to the console:

var ax25 = require("ax25");

var tnc = new ax25.kissTNC(
    {   serialPort : "/dev/pts/1",
        baudRate : 9600

    function(frame) {
        //console.log("Received AX.25 frame: " + frame);
        var packet = new ax25.Packet({ 'frame' : frame });
        console.log(new Date() + "From "
            + formatCallsign(packet.sourceCallsign, packet.sourceSSID)
            + " to "
            + formatCallsign(packet.destinationCallsign, packet.destinationSSID));

        if(packet.infoString !=""){
            console.log(">  " + packet.infoString);

 * Formats a callsign optionally including the ssid if present
function formatCallsign(callsign, ssid){
    var formattedCallsign = "";
    if(ssid == "" || ssid == "0"){
         formattedCallsign = callsign;
        formattedCallsign = callsign + "-" + ssid;

   return formattedCallsign;

The output for  received messages so far looks like this:

Wed Apr 19 2017 23:10:00 GMT-0700 (PDT)From KBERR  to KJ6NKR

Wed Apr 19 2017 23:12:05 GMT-0700 (PDT)From AE6OR  to BEACON

>  Š¤¤@à–¤ˆŽ@@`–„Š¤¤@`®žžˆ²@`–„Š¨@`¨‚žŠ@aðHello from 5W Garage packet node AUBURN 73's Steli !

Wed Apr 19 2017 23:12:08 GMT-0700 (PDT)From AE6OR  to BEACON

>  Š¤¤@à–¤ˆŽ@@à–„Š¤¤@ஞžˆ²@`–„Š¨@`¨‚žŠ@aðHello from 5W Garage packet node AUBURN 73's Steli !

Wed Apr 19 2017 23:16:49 GMT-0700 (PDT)From K6JAC -6 to ID    


Wed Apr 19 2017 23:19:31 GMT-0700 (PDT)From K6WLS -4 to ID    

>  Network Node (KWDLD)

Wed Apr 19 2017 23:19:50 GMT-0700 (PDT)From NM3S   to BEACON

>  Mike in South Sac.  Please feel free to leave a message. 73's