Ask your Expert: Nico teWinkel - Software Engineer who specialises in firmware, C and Java.

Hello Arduino guys!

This is the first time ever, that i am entering an arduino forum and there are so many options around here, i am not even sure that i am posting my question in the right place - if i am not, can you please explain or send me links or keywords for the correct pages? Thanks a lot!

Here is my question:

I am trying to build a robot, that uses the "Bluecontrol" android application.

Here is the Bluecontrol app on google play:

https://play.google.com/store/apps/details?id=com.gundel.bluecontrol&feature=search_result#?t=W251bGwsMSwxLDEsImNvbS5ndW5kZWwuYmx1ZWNvbnRyb2wiXQ..

The robot, called "MegaPed", building instructions and arduino sketch are detailed on www.instructables.com, on this page:

http://www.instructables.com/id/MegaPed/

I have done everything exactly according to written and drawn instructions on that page, with only one change:

I have switched this BlueSMiRF bluetooth module, which is quite expensive:

http://www.amazon.com/SparkFun-Bluetooth-Modem-BlueSMiRF-Silver/dp/B004GTUI76/ref=sr_1_5?s=electronics&ie=UTF8&qid=1332730295&sr=1-5

With this JY-MCU Arduino Bluetooth Wireless Serial Port Module:

http://www.ebay.com/itm/251258723414?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Now, my problem is, that after uploading the sketch - My android smartphone, is trying to connect with the bluetooth module, but shows that the module (called "linvor" on the smartphone screen) is: "Paired but not connected" - And i am unable to proceed and control the robot from the Bluecontrol application.

Maybe you can help me solve this problem or refer me to someone who might help me to solve this problem?

Thanks a lot,

Roi Neustadt.

Hi Roi,

Probably the best thing to do is to just post your question once, as a new topic (marked as a question), in the Arduino forum. Posting the same question in many different areas makes it more difficult for people to work together to help you figure it out. For all the posts you've already made, you might want to edit them to point to the one central question.

Your project sounds like quite the interesting one, but unfortunately I don't know enough about the subject to be able to help much, sorry. I do have the same type of BT module as you have, and what you're working on is something that's on my want-to-do list, so if I have some time in the next week I will have a look.

Cheers,

-Nico

Hello Nico!

Thanks for these initial forum go about instructions!

I will be waiting to hear from you how you have managed with building the bot, the JY-MCU version !!

Thanks,

Roi.

Hi Roi,

A good step in debugging is to break it down into pieces. In this case you are debugging the BT connection, so step one is to test just the BT communications.

I tried it last night, by simply hooking the BT module to pins 10 and 11 and using it as a new serial port to read from. Then everytime something is read from BT it shows on the Serial monitor.

I was able to use the app to connect and send single characters to my serial terminal display. To connect the app to the linvor BT module, all I had to do is press the menu button and choose "connect". I was doing this on a Samsung Galaxy S with Android 2.3.

This is the code I used on my Arduino Uno, which is just a slight modification of the built in sample SoftwareSerial->TwoPortReceive.

/*

  Software serial multiple serial test

Receives from the software serial port,

sends to the hardware serial port.

*/

#include <SoftwareSerial.h>

// software serial #1: RX (=TX of BT module) = digital pin 10, TX (=RX of BT module) = digital pin 11

SoftwareSerial BTport(10,11);

void setup()

{

// Open serial communications and wait for port to open:

  Serial.begin(9600);

  // Start the software serial port

  BTport.begin(9600);

  Serial.println("Data from Bluetooth:");

}

void loop()

{

  // By default, the last intialized port is listening.

  // when you want to listen on a port, explicitly select it:

  BTport.listen();

  // while there is data coming in, read it

  // and send to the hardware serial port:

  while (BTport.available() > 0) {

    char inByte = BTport.read();

    Serial.write(inByte);

  }

}

Hello Nico!

I have tried to compile, upload and watch trough the serial monitor the test code here, that you sent me and it was working fine.

Then i discovered that i need to connect to the bluetooth module, from within the Bluecontrol app and not from the smartphone bluetooth settings - and at last the bluetooth module led stopped blinking and turned on constantly - and the Bluecontrol app gave an indication that it is connected to the "Linvo".

I though that at last i will be able to make the robot servos move, according to touch commands on the Bluecontrol, on my smartphone screen - but no, it still did not work.

Could that be because i have connected this time only one servo and not all the 4 in the diagram?

The servo was moving occasionally, just very small movements, but that could also be only because of unconstant voltage from the LiPo battery.

I tried to chage all the values in the code, which are tenths of microseconds to thousands of microseconds, in oredr to find out if the servo movements are random or originate from my pressing on the smartphone screen - but the servo did not start moving for longer periods.

Do you have any idea, how should i try to tackle the problem this time?

Thanks,

Roi.

Hi Roi,

Try adding some Serial.println statements to the robot sketch to display debug information on the Serial monitor to show that the robot is actually receiving the commands.

And/or instead of moving servos, turn on an LED for a second or so when a command is received. You could have one LED per servo or per command, for example.

I still haven't checked out that robot you pointed out... I really should try that out

Cheers,

-Nico

Hi Roi,

Try adding some Serial.println statements to the robot sketch to display debug information on the Serial monitor to show that the robot is actually receiving the commands.

And/or instead of moving servos, turn on an LED for a second or so when a command is received. You could have one LED per servo or per command, for example.

I still haven't checked out that robot you pointed out... I really should try that out

Cheers,

-Nico