DEV.BG tech talk #3

I did a tech talk about my ESP32 based IoT control hub project on Feb 5th, 2019 at Work & Share Coworking Space Sofia. Over 100 people signed up for the event organized by DEV.BG, it was a pleasant surprise to see so many IoT enthusiasts show up – thank you! Unfortunately, I wasn’t allowed…

ESP32 OTA firmware update using MQTT over SSL

My recent IoT projects are capable of performing OTA firmware updates, I have previously blogged about the importance of this capability. I normally use MQTT over SSL as a means of communication between the edge nodes and the cloud backend, and the devices are subscribed to a dedicated ‘firmware notifications’ topic that alerts them of…

Thoughts on time/date management on IoT nodes

Accurate time/date information is crucial for the correct operation of IoT nodes. From a security perspective, time/date information is necessary to perform SSL certificate validations. If your embedded device’s clock isn’t accurate, you can’t ensure the presented server certificate hasn’t expired, or is not yet usable, leading to connection rejection. In that case, your device…

TFT32 Wi-Fi configuration GUI

I am working on a thermostat control project using the TFT32 hardware, let me share a video of the Wi-Fi configuration GUI (still work in progress). The Wi-Fi provisioning via GUI addresses one of the significant challenges when setting up an IoT product – the initial setup. I have already blogged on this subject a…

Upgrading my fan coil thermostats

We use a DIY air-to-water heat pump for climate control (heating/cooling) of our house with a combination of water underfloor heating and fan coils in the rooms. The fan coils are equipped with basic thermostats that allow for heat/cool mode setting, desired temperature and fan speed. We never use fan speed setting other than lowest, as…

BBoilRF

This blog post is about a project I have been working on lately, the BBoilRF. It is a general purpose internet-connected relay actuator/gateway with support for low power, battery operated remote wireless sensor nodes. It was designed primarily for use as a thermostat with an option for wireless temperature sensors capability, but is highly configurable…

ESP32

I’m one of the lucky 200 that got their hands on the early beta of Espressif’s new ESP32 chip evaluation board. It is the “big brother” to the popular ESP8266, Espressif has though noted that it should not be treated as an ESP8266 replacement and that it is targeting “different market”. The specs are impressive indeed,…

RFM69 to MQTT gateway using ESP8266

I’ve mentioned my plans for this project during the IoT hangout session few months ago, it has finally materialized as working prototype. The blocker so far was the lack of ESP8266 RFM69 driver and free time on my end, so I’ve teamed up with Andrey Balarev to solve this. Andrey is an IoT enthusiast + embedded systems…

The initial setup problem

The typical end-user of your IoT products wants them up and running fast, with minimum hassle once they bring them home. They don’t want to be presented with initial configuration mechanisms/options they don’t understand, and their enthusiasm quickly diminishes if you make them struggle to get the product going. Page views: 3053

MQTT topic tree structure improvements

I’ve been unhappy with my old MQTT topic tree structure for quite some time now and did some thinking/research on how to improve it. Google pointed me to Tinkerman’s article on a similar subject, and I started planning on improvements. I will repeat a quote I used in my last post “If you can’t measure it, you can’t…