Using SIM800L to POST Data with HTTP and HTTPS

The SIM800L can POST data to web sites/services using both HTTP and HTTPS.  The procedure for both is nearly the same with the exception of a few additional parameters needed for the HTTPS POST version.  To enter AT commands into the serial monitor, I’ll use the sketch (shown below) my prior post on using the SIM800L to send data via GET .  I connected the SIM800L to an Arduino UNO clone with the following conmnections:   5V -> VIN, GND -> GND, D8 -> TX, D7 -> RX. There are a few gotchas to watch out for. Be sure to set the serial monitor to 9600 baud and also set the line ending drop down to use “Both NL & CR”.  A largish cap […]

HackerBoxes #13 – WiFi Car Controlled with Blynk Joystick and HC-SR04

The code below is what I have thus far for the WiFi car that came with HackerBoxes #13.  I hooked up a Blynk 2 axis joystick to control the car, and it works pretty good. The “tires” for the car are terrible on the surfaces around my house – wood floors, tile, concrete.  The tires slip all over the place, and it’s really difficult to keep the car moving in a line with the back end of it sliding all over the “road”.  No carpet in our house, so maybe it works better on a surface like that. The HC-SR04 sensor is the general ultrasonic sensor you’ve probably seen before.  Very easy to hook-up and seems fairly accurate for the […]

HackerBoxes #13 – Using Blynk’s 2 Axis Joystick with Arduino and ESP8266

This is the Arduino version of the code to use a 2 axis Blynk joystick widget.  It turned out to be easier to code, but more difficult to debug than the NodeMCU version.  I put the car through a few laps around the basement, and it seems to work pretty well other than the wheels are way out of alignment and the tires are sort of bald…makes it a little hooptie, but it still works much better than the 4 pushbutton control version supplied with HackerBoxes #13.  Playing around with sensors and open SDK version now.  Really fun project – we’ve enjoyed it so far. A couple other notes – be sure you check to make sure your motor leads […]