Posts with «serial port» label

Secret Serial Port for Arduino/ESP32

If you use the Arduino IDE to program the ESP32, you might be interested in [Andreas Spiess’] latest video (see below). In it, he shows an example of using all three ESP32 UARTs from an Arduino program. He calls the third port “secret” although that’s really a misnomer. However, it does require a quick patch to the Arduino library to make it work.

Just gaining access to the additional UARTs isn’t hard. You simply use one of the additional serial port objects available. However, enabling UART 1 causes the ESP32 to crash! The reason is that by default, UART 1 uses the same pins as the ESP32 flash memory.

Luckily, the chip has a matrix switch that can put nearly any logical I/O pin on any physical I/O pin. [Andreas] shows how to modify the code, so that UART 1 maps to unused pins, which makes everything work. it is a simple change, replacing two parameters to a call that — among other things — maps the I/O pins. You could use the technique to relocate the UARTs to other places if you choose.

If you want to learn more about the ESP32, we covered a good set of tutorials for you to check out. Or if you just want a quick overview, you can start here.

Filed under: Arduino Hacks, ARM
Hack a Day 17 Aug 16:30

Controlling a robot from javascript (g+ hangouts application)

Hi guys

I'm trying to create a google+ hangouts application to let us to control a robot (like magabot, for example), directly from there.

I already created the interface of the application, it is actually pretty simple, if you want to have a look it is hosted here:

read more

Delta Robot

Primary image

What does it do?

Move around in space

Homemade delta robot. It uses an Arduino as a servo/relay controller. Data is transferred over serial port from a homebrewed Qt application to the Arduino.

It was made as a high school project.

Cost to build


Embedded video

Finished project



Time to build


URL to more information