<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>esp8266 | Blue Duck Valley Rd</title><link>https://juju.nz/michaelh/categories/esp8266/</link><atom:link href="https://juju.nz/michaelh/categories/esp8266/index.xml" rel="self" type="application/rss+xml"/><description>esp8266</description><generator>Source Themes Academic (https://sourcethemes.com/academic/)</generator><language>en-us</language><copyright>© 2017-2025 Michael Hope</copyright><lastBuildDate>Fri, 06 Feb 2015 19:34:25 +0000</lastBuildDate><image><url>img/map[gravatar:%!s(bool=false) shape:circle]</url><title>esp8266</title><link>https://juju.nz/michaelh/categories/esp8266/</link></image><item><title>Impressed with NodeMCU</title><link>https://juju.nz/michaelh/2015/02/impressed-with-nodemcu/</link><pubDate>Fri, 06 Feb 2015 19:34:25 +0000</pubDate><guid>https://juju.nz/michaelh/2015/02/impressed-with-nodemcu/</guid><description>&lt;p>
&lt;a href="http://nodemcu.com/index_en.html" target="_blank" rel="noopener">NodeMcu&lt;/a> is a Lua interpreter with a good set of support libraries for the far-too-cheap
&lt;a href="https://www.olimex.com/Products/IoT/MOD-WIFI-ESP8266-DEV/#" target="_blank" rel="noopener">ESP8266&lt;/a>. I’m impressed with how easy it is to script up a Wifi connected thermometer using a
&lt;a href="http://www.maximintegrated.com/en/products/analog/sensors-and-sensor-interface/DS18B20.html" target="_blank" rel="noopener">DS18B20&lt;/a> 1-wire thermometer,
&lt;a href="http://mqtt.org/" target="_blank" rel="noopener">MQTT&lt;/a> for publishing, and Wifi to a
&lt;a href="http://wiki.openwrt.org/toh/tp-link/tl-mr3020" target="_blank" rel="noopener">OpenWRT router&lt;/a> for the transport.&lt;/p>
&lt;p>Have a look at the NodeMcu git repo for the
&lt;a href="https://github.com/nodemcu/nodemcu-firmware/tree/master/app" target="_blank" rel="noopener">bundled libraries&lt;/a> which include a JSON parser, MQTT, spifs, and software based I2C, 1-wire, and PWM drivers.&lt;/p>
&lt;p>It’s very RAM hungry though. I had a hack and got it up to 25 k of free heap, but that’s only just enough for a single device and MQTT connection.&lt;/p>
&lt;p>
&lt;a href="https://juju.net.nz/michaelh/blog/wp-content/uploads/2015/02/IMG_20150206_2036122.jpg" target="_blank" rel="noopener">&lt;img src="https://juju.net.nz/michaelh/blog/wp-content/uploads/2015/02/IMG_20150206_2036122-1024x827.jpg" alt="IMG_20150206_203612~2" width="584" height="471" class="aligncenter size-large wp-image-250" srcset="https://juju.net.nz/michaelh/blog/wp-content/uploads/2015/02/IMG_20150206_2036122-1024x827.jpg 1024w, https://juju.net.nz/michaelh/blog/wp-content/uploads/2015/02/IMG_20150206_2036122-300x242.jpg 300w, https://juju.net.nz/michaelh/blog/wp-content/uploads/2015/02/IMG_20150206_2036122-371x300.jpg 371w" sizes="(max-width: 584px) 100vw, 584px" />&lt;/a>&lt;/p></description></item></channel></rss>