13 votes
Accepted

Want to create bluetooth audio control (volume up/down, play, pause, etc.) for smartphone

Bluetooth supports multiple protocols for multiple purposes. There is low latency low quality monorail bi-directional communication with a little bit of bandwidth for control for Bluetooth phone ...
  • 6,756
8 votes
Accepted

What are the fundemental differences of different Bluetooth modules for beginners?

As far as simplicity is concerned, HC05 would be the way to go. It is by far the most popular and there are a tonne of tutorials on using it (just a quick google search). As for the differences: The ...
8 votes

Anyone have example code for ESP32 as media controller for Android/iPhone Media Apps

Well after I posted this question, I kept googling. Literally hours of googling at this point. Then I stumbled across this example: https://github.com/T-vK/ESP32-BLE-Keyboard I wrote that sketch to my ...
  • 141
6 votes

Over-the-air upgrades?

The best and easiest solution I've found is to use the Bluefruit EZ-Link from Adafruit. They have a module you plug into the Serial/Power/reset pins (link here) or a shield for the uno (link here). ...
  • 446
6 votes

Lowest power possible in Arduino

The issues regarding efficiency of power are: The CPU speed The Voltage The Power Regulator (not supply) The Peripherals Address each one of these and don't over look any of them. Or any sub ...
  • 2,443
6 votes
Accepted

Choosing wireless tech for lowest possible lag

I've used NRF24L01+ chipset 2.4GHz wireless modules with Arduino before, and found them to be great, and super cheap (~$10 for 10 of them on ebay!). They have 3 modes of transmission: 250kbps, 1Mbps, ...
  • 373
6 votes
Accepted

Can I measure velocity from an accelerometer? How accurately?

The sensor in itself can't provide you the velocity. I have used it accelerometers in a couple of projects the easiest way to get the velocity is to constantly monitor acceleration changes and ...
  • 196
6 votes
Accepted

What is the difference between Bluetooth module HC-05 and HC-42 for Arduino?

It's different technology. the HC-05 uses the old Bluetooth 2.0 standard. The HC-42 in contrast uses BLE (Bluetooth Low Energy) in version 5.0. So you have to decide what technology you want to use, ...
  • 14.7k
5 votes

Which wireless technology should I use for my outside "check-if-door-is-open" project?

I agree with @Gerben - the nRF24L01+ would probably be the most suitable for your application. It should have enough range to go 15m through a few walls, and the cost is about as cheap as you can get....
  • 103k
5 votes
Accepted

Is it possible to create an electromagnetic wave using PWM?

I had a toy project a while ago that generated AM radio. Code Code for Uno or any Atmega328 based boards: const byte ANTENNA = 9; void setup() { // set up Timer 1 TCCR1A = bit (COM1A0); //...
  • 35.5k
5 votes
Accepted

Will enabling parity bit actually decrease corruption?

Parity doesn't, and was never intended to, decrease corruption. All parity does is allow you to DETECT errors. If you detect errors, you still have to handle them. Parity in memory is usually fatal -...
5 votes
Accepted

How do I make a proper long string scanner to detect specific tags in a stream of characters?

Another option is to not save the characters in buffer but instead check each one as they arrive to see if the character is the next in the tag sequence. This has the advantage that you don't need a ...
  • 2,100
4 votes

Over-the-air upgrades?

We have implemented remote updates on a Arduino Pro Mini (ATMega328P) by putting a "boot" command into the normal firmware. How it works is: The host sends the command "boot" to the remote Arduino. ...
  • 2,886
4 votes

Arduino Pro Micro, get data out of Tx pin?

So I stumbled upon this thread while having similar problem, but with HC-05 module. So because I have too much free time on my hands during finals (no I don't) I decided to create a small github repo ...
  • 143
4 votes
Accepted

Send array of Infrared codes

Well as usual it was something stupid (-__-) I changed the byte array for long and it worked perfectly. Here is the complete code working(): #include <IRremote.h> // IR Library - Encode/...
4 votes
Accepted

Running multiple tasks at once

What you want to do is rather easy task, you just need to forget about delay() function. When writing some more complex programs using it is generally a bad idea, as it blocks code execution, so you ...
  • 196
4 votes

Choosing wireless tech for lowest possible lag

Have you considered using real time clocks? You could synchornise them all ahead of time and then use any wireless protocol. Once a button is pressed, you'll look for the unit that reports the ...
  • 119
4 votes

Can I use a 6 pin Bluetooth module in a 4 pin socket?

After some more concerted searching I have found the answer on Success Using the JY-MCU (linvor) Bluetooth Module: The module has 6 pins labeled on the back, but most modules only have 4 of those ...
  • 2,803
4 votes

Programatic FOTA (Firmware-Over-The-Air) upgrades with Uno R3

There's two ways you can go about this - hardware and software. To do it in software would mean writing a new bootloader that supported whatever wireless medium you chose. The bootloader might end ...
  • 103k
4 votes

Can I measure velocity from an accelerometer? How accurately?

I work with Arduino-based autopilot modules, which usually use similar sensors in addition to GPS data to maintain a reasonable estimate of its position/velocity/acceleration. If you were to add ...
  • 81
4 votes
Accepted

How to make a Smart Light Bulb?

You could use an ESP8266 NODEMCU. There is an example for making it emulate a Hue bridge ( https://github.com/probonopd/ESP8266HueEmulator ). To have the official bridge control your lights would ...
4 votes

Why is there a plastic sleeve on my HC-05 bluetooth module

It is to protect it. You should keep it so that the modules lasts longer. If you remove it, just don't do anything stupid.
  • 2,843
4 votes
Accepted

Getting Bluetooth addresses of connected devices via Arduino Uno?

The HC-05 has an AT command, AT+BIND?, that will tell you which slave device it is connected with currently. Since you can connect to one device only at the same time, your array is going to be a very ...
  • 1,551
4 votes
Accepted

SPP-C and HC-05 are they the same thing or something else?

In theory they are the same and have the same capabilities. Practically they are not. With SPP-C you get twice the headache for half the price as for HC-05. In had to find it out the hard way Sending ...
  • 1,485
4 votes

Connecting a servo via HC05 and HC06

You cannot. You will need an Arduino at the servo end to generate the PWM signal from serial instructions sent over Bluetooth. Since PWM is (typically) 8-bit and serial is (typically) 8-bit you could ...
  • 103k
4 votes

One of the LEDs on my Arduino is very dim

You need to add this line for the other LED pin: pinMode(ledPin2, OUTPUT);
  • 2,366
4 votes

Can you help me trim my code?

The documentation for the MCUFRIEND_kbv project has a file describing how to use. This document has the statement: Most of these controllers are #define SUPPORT_xxxx by default. You can save Flash ...
  • 6,942
4 votes
Accepted

SoftwareSerial read until available is empty only works with delay

Serial does not transmit data as one bunch, but byte by byte. There can easily be some little delays introduced, especially, when transmitted via a packaged protocol like bluetooth, long enough, for ...
  • 14.7k
3 votes

Over-the-air upgrades?

The Arduino Yun can be remotely reflashed (either via wifi or network cable): you'll have to select its IP address under the "Tools > Boards" menu of the Arduino IDE and then press the upload button ...

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