BuildStatusTrafficLight

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Project BuildStatusTrafficLight
Stoplicht.jpg
A traffic light showing CI build status
Status Completed
Contact bertrik
Last Update 2018-11-20

Introduction

The end result of this project is a traffic light that shows the status of a software build.

It can show the following statuses:

  • red: build has failed to compile
  • yellow: build compiles but a unit test fails
  • green: build is OK and all unit tests succeeded
  • yellow flashing: build status unknown, e.g. still starting up, connection problem, or we receive a status we don't understand

Status

 2018-11-18 Soldered new, brighter LEDs into it and connected the ESP8266, no sound yet
 2018-11-02 Played with ESP8266 software, particular playing audio using the 1-transistor-circuit
 2018-10-30 Received that hardware, opened it up etc.

Hardware

I use an ESP8266 (Wemos D1 mini) along with a modified toy traffic light (see below).

I'm using this toy traffic light, modified for use with the ESP8266. It lights the lanterns in order, speaking some Chinese for each lantern. The lanterns are basically white LEDs behind a colored piece of transparent plastic.

I replaced the white LEDs with high-brightness coloured ones (red, orange, green). The ESP8266 can officially source about 12 mA and sink about 20 mA of current, I'm using a single 150 ohm resistor in the common ground wire of the LEDs. It would be better to actually put it in a common Vcc wire, because the ESP8266 can more easily sink current than it can source it.

I haven't put in the sound circuit yet, that would be on the RX pin along with usage of the ESP8266Audio library in software and the 1-transistor driving circuit.

Software

Source code can be found on github.

It is written in C/C++ for Arduino for quick and easy development using existing libraries, like WifiManager, PubSubClient.

The plan is to simply listen to an MQTT stream. To keep things secure and secret as much as possible, I plan to use an encrypted link to the MQTT server along with a username/password.

External links