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Neil Kenyon's Blog

24 posts
Where am I?   At the end of my last Blog, I had a semi-functional Arduino IDE/ESP8266 development environment. It would sometimes compile a sketch correctly and sometimes it would fail to compile the same, unchanged sketch, usually with errors relating to (untrue) multiple library references. I have wasted hours attempting to sort this out and failed miserably.   However, because the environment would sometimes behave, I decided to satisfy my desire to make some progress with develop ...
WHAT DID I DO?   Wednesday 27 November 2019 was cold, raining and generally miserable, so I decided to try and get back to some project work. I hadn't done any coding with my Arduino IDE since about May this year, so I thought I'd better check for upgrades before doing anything else........this turned out to be a bad mistake because I didn't make a note of the current version numbers of the IDE, the libraries I had installed and the ESP8266 package, so when it all seemed to go wrong, I did ...
When the final long term test of power consumption of my Wemos d1 mini temperature monitoring system was complete:   Power Consumption of a Wemos D1 mini ESP8266 - Long Term Test 3   I decided to try recharging the battery - from a mobile phone charger - whilst the Wemos d1 mini was still connected, so that I could monitor the charging process.   After charging the battery for just over 2 hours I had to go out, leaving the house empty, except for #sadiethecat1409 (Instagram). ...
Having returned from my holiday in the winter sun , I removed the battery from its holder and set about fitting the XH2-2.54mm female connector to the battery holder leads.   I then modified the sketch to reduce the drift in the sleep time which is evident in the chart from Long Term Test 2, repeated below:     I checked the battery voltage and was pleased to see that it still showed 3.74 V on my DMM. Rather than charge it, I decided to reconnect the Wemos d1 mini system and s ...
Recap  In a previous blog:  https://www.element14.com/community/people
eilk/blog/2019/02/17/esp8266-power-consumption-further-studies  I observed that the power consumed by the Wemos d1 mini during deep sleep was pretty negligible - about 22.7 mAh over a period of 100 hours, including the Serila-USB interface and the resistor chain used to connect the battery to the A/D converter. I concluded, therefore, that the majority of the power consumed was during the actual sketch execut ...
neilk

Send an Email from ESP8266

Posted by neilk Feb 22, 2019
Background  In previous blogs, I have described my investigations into using an 18650 3.7V 2400mAh battery to power a Wemos d1 mini ESP8266, via a Wemos battery shield, which plugs directly into the d1 mini, just like an Arduino shield.   While waiting for my latest long-term power consumption tests to complete, I wondered if it might be possible to send an Email from an ESP8266, to alert me that the battery voltage is reaching a critical level, or perhaps, just to confirm that the b ...
Introduction  In a postscript to my last Blog:   https://www.element14.com/community/people
eilk/blog/2019/02/14/investigating-the-power-consumption-of-a-wemos-d1-mini-esp8266   I concluded that the power consumption of the Wemos ESP8266 during Deep Sleep was negligible - around 227 microAmps. This includes the current drawn by the USB-Serial interface and extra current drawn by the battery monitoring resistor chain.   This represents 22.7 mAh over 100 hours and is pret ...
Background  In my previous Blog: https://www.element14.com/community/people
eilk/blog/2019/02/14/investigating-the-power-consumption-of-a-wemos-d1-mini-esp8266   I described my investigations into the power consumption of a Wemos d1 mini ESP8266 device, powered by an 18650 2400mAh Li-ion battery, via a Wemos battery shield which has the same form factor as the d1 mini. The Wemos was reading from two DS18B20 temperature probes and also reading the battery voltage at 1 minute interval ...
Background  I'm working on a long term project (several years now, if I'm honest!), to provide environmental monitoring and possibly some environmental control for my greenhouses. I've already investigated temperature monitoring using DS18B20 probes, which I've found very reliable and easy to use, provided you don't need a very long cable run!   I was inspired to pick the up project again by this blog: https://www.element14.com/community/community/project14/mixing-electronics-water/ ...
I've long harboured the dream of remotely monitoring the temperature in my greenhouses, but have been put-off by the need to run cables, or invest in relatively costly WiFi shields for my Arduinos. I'm sure there are other solutions, but let's not go there   And then I read this blog from ntewinkel:  https://www.element14.com/community/community/project14/mixing-electronics-water/blog/2018/04/13/remote-temperature-monitoring   I was already aware of ESP8266 devices, but hadn't a ...
My early Blogs about moving data between Arduino and Android apps developed using MIT AppInventor were posted back in 2014. Since then I've learned a little more about some of the features of AppInventor and also how to use Arduino SoftwareSerial.   Connecting the Arduino UNO to the HC06 Bluetooth Adapter   My 2014 Blogs had the HC06 TXD and RXD connections "piggy-backed" onto the hardware UART of the UNO - pins RXD/D0 and TXD/D1.   Note that the signal to the RXD input of the ...
My previous post included a photograph of a very untidy Cybot - it was a bit of a lashup, but it worked! I have resurrected some practical skills that have lain dormant for over 20 years and made a fairly neat and tidy strip board carrier for an Arduino Nano, the HC-06 Bluetooth module and the L9110 break-out board. The battery box for the motors has its own switch and is connected to the strip board with a pair of screw terminals. The 9 V battery for the Nano mounts under the Cybot chassis ...
I connected an HC-06 Bluetooth adapter, across the Arduino Rx and Tx,  as in my previous Blog posts.   In MIT App Inventor, I created the following Android design:   Since I already had an Arduino sketch which controlled the motors (previous post), I decided to make the Android program simply mimic the keyboard input of that  sketch. I did, however, remove the menu output to the serial monitor.   Ignoring the Bluetooth connect and disconnect blocks, the control b ...
More years ago than I care to remember (probably 15), I foolishly subscribed to a magazine called Real Robots, published by Eaglemoss. Each monthly part included components which, when you had spent a small fortune buying the magazine, would let you build a robot - Cybot.   I became disillusioned when I realised that all I would be doing was screwing mechanical parts together and plugging in already fully populated PCBs, some of which carried pre-programmed microprocessors: I had assumed m ...
This post builds on previous posts, drawing together the use of AppInventor to create an Android app to send commands, via Bluetooth, to an Arduino controlling a stepper motor using the AccelStepper library. Because the HC06 Bluetooth board is connected to the Arduino serial I/O on Digital pins 0 and 1, it is possible to develop and test the Arduino sketches  independently of the Android Apps. The data stream anticipated from the Android app, via Bluetooth, can be simulated by opening the ...