Avoiding the use of string manipulation functions. Several changes were implemented to reduce the code size: Changing to the TMP35 temperature sensor because is easier to read (don’t need a library ). The Trinket Sketch: At first, just ported the code from a working example made with the Meduino NANO and the DHT22 temperature sensor, finding out that the code size will be a problem. Green: Trinket analog input (TMP36 Vout). Use enough solder to obtain a good mechanical resistance. Then, using a breadboard as guide and support, sold the right-angle header.

The procedure is very simple: First cut (remove) the row of pines closer to the board border. Making the ESP8266 breadboard friendly: To modify the ESP8266 we need a 0.1″ 4-pin right-angle male header. The L4931 (250 mA) is working at first. A 470 uF capacitors is needed at the output. Then we need to use another 3.3V power source. The 3.3Vregulator in the Trinket only supply 150mA max. Power considerations: The ESP8266 is power hungry when is communicating with a Wi-Fi spot.

Let’s make the Trinket do the job using just the Arduino IDE. Anyway was a fun project, is great to see the small ATtiny85 acting as a Web Client.

Programming the ATtiny85 with an ISP programmer will permit the use of the full 8K programming memory. Then I realized, due the reduced space in the Trinket (5.310Kb for code), the usability of such libraries it’s not so simple. In this case I wanted to keep the solution in the Arduino environment to take advantage of many ready-to-use libraries and examples. The ESP8266 can be used alone thanks to the apparition of several environments like LUA, C, Micro Python etc. This is a small and low cost implementation of IoT (Internet of Things, possibly one of the next technological revolutions). Ending the temperature to a ThingSpeak channel using the TMP35 sensor.

Adafruit trinket 5v first project