Autonomous IoT Temperature Monitoring with solar charger

Autonomous IoT Temperature monitoring with solar charger:

Warning:
Some knowledge (that can all be found over internet) are deemed necessary to do the electronique assemblying and software adaptation. It is not too difficult but requires some experience in this.

Hardware Bill of material

• Solar Panel : 2 x 2.5W 5V/500mA Polycrystallne Epoxy Solar Cells DIY Solar Panel

• Solar charger: 1x DF ROBOT SOLAR CHARGER V1.0 https://www.dfrobot.com/product-1139.html

• Battery : 1 x LiPo 3.7v mini 1000 mA or better LiPo 18650 3.7V (3500 mA) This latter is better in case there is no sun during several days or weeks.

• Regulator; 1 x regulator LDO 3.3v - In my case I modified an existing reg board. I have replaced an AMS1117 by a MCP 1825S due to its very low supply current (almost no consumption) when no current is drawn - https://www.microchip.com/wwwproducts/en/en531456 - Warning the MCP1825S has a different pin layout than an AMS1117

• IoT Board ESP8266

• Temperature sensor DS18B20 + R4,7K ohm https://datasheets.maximintegrated.com/en/ds/DS18S20.pdf
  -Water proof junction box IP55 80X80X36 MM

• rc steel cord: diameter 1mm length 100mm max for lock the hinges in the front panels ( in my case was not necessary) qnd the junction box to the soloar stands.

Software:

• Web-app for processing and logging temperature https: https://emoncms.org/ This Web-app can be used on-line or a version can be installed on a raspberry3 board see https://github.com/emoncms/emoncms

• Code for the ESP8266 app provided as-is (to be adapted to your configuration) . IDE for code development Arduino 1.8.5

• 8 x small screws (mines come from rc servos)

• 1 x battery plug (depnending on the connector used to connect the solar panel to the solar charger box;

Resources:

• https://www.elec-cafe.com/temperature-sensor-on-the-web-with-esp8266-and-ds18b20/

• https://tzapu.com/minimalist-battery-powered-esp8266-wifi-temperature-logger/

Remark:

• I used it in an unattended way during 1 year without any issue with the battery (second hand - good one - from a PC battery pack)
• The ESP code can be extended so to send mails with the info on temperature
• Other sensors can be used like the DHT 22 see in the resources ; Then the coe needs to be adapted.

Hope this helps

Have fun