ESP8266 based Glucose Monitor

I've created this little device for our bedroom to be able to always see the latest value and trend during the night. With this you don't need to grab your mobile phone to check the current value but it will simply be displayed. During the night it is dimmed down and during the day it is brighter. In case of a too low or too high value the brightness will be extrem bright and it starts blinking for 30 sec. In addition it will beep 5 times in case the value is too low.

ATTENTION:

Please be aware that you need to be able use a soldering iron. It's not really hard to assemble the whole thing but might need a bit of training to get the soldering right. Some of the boards below you can also buy in an assembled version (maybe all of them, I'm not sure).

These are the things you gonna need to build it up on your own. 

The feather wing tripler from Adafruit

The Adafruit ESP8266 Feather Huzzah

The DS3231 precision real time clock from Adafruit.

The FeatherWing Proto board from Adafruit.

A piezo buzzer for the alarm. I'm using this one from Adafruit.

A MAX7219 8x32 four in one led module (you should choose the red color which is more convenient to look at in the night). I bought mine over at Amazon but will find them everywhere.

Some jumper wires (usually male/female should be enough but it depends on your MAX7219 board connectors).

Hook it all up...

The Buzzer will be put onto the Protoboard as shown on the image below. The Buzzer needs to be connected to PIN 15 of the ESP8266.

There is also a little tutorial over at Adafruit on how to hook up a buzzer to a ESP8266 Feathe Huzzah.

If you have finished this you simply can put the modules on the Tripler board as shown on the next image.

Now the next step will be connecting the MAX7219 board to the ESP8266 as shown on the image below.

You need to connect the following pins:

MAX7219                     ESP8266 Feather Huzzah

CLK (Orange)       ->           MOSI

CS (Green)           ->           RX

DIN (Yellow)         ->           MISO

GND (Brown)       ->           RTC

VCC (Red)           ->           3V

Now when all these things are done you can download the code from github.

If you open the code in your Arduino IDE you just need to edit 3 things.

• In line 41 you need to put in the SSID (name) of your wifi network
• In line 42 you need to put in the password for your network
• In line 46 you need to put in the URL of your nightscout server

If you now compile the code you can deploy it to your connected ESP8266 Feather Huzzah and should hopefully see the current blood glucose value from your nightscout server.