LabVIEW
labview arduino bluetooth
HI I amhaving trouble with getting my arduino cummunicationg with labview over bluetooth, And I cannot quite pin point the root cause of the problem, please read on.
Aim: To simultaneously read the values from pin A0 and pin D8 on the Arduino UNO over Bluetooth to LabVIEW. And display them on the front panel.
It is important to note I achieved this many weeks ago but an intermittent problem has crept in somewhere and now I’m trying to debug it.
Method: I have uploaded the LIFA base firmware to my Arduino. The Bluetooth device I am using is the SparkFun Bluetooth Mate Silver module (https://www.sparkfun.com/products/12576), I then followed the instructions on the on to connect it: http://digital.ni.com/public.nsf/allkb/D86D6E2927F9C37A8625788E0077E86B
My Laptop is a Toshiba Satellite L755 with built-in Bluetooth
Code
I took the Arduino Analog read pin example from labview and reconfigured it to work over Bluetooth so all I changed when moving to the Bluetooth connection was the following setting;
- Baud Rate: 115200
- Connection type: Bluetooth/ BlueSmirf
- COM port : 40 (On my machine)
I have also built a similar loop to read the input to pin D8.
Please see labview VI below and attached the file below.
The Problem: It works quite well for a period of time (up to 20minutes sometimes will give erroneous readings from the outset) i.e. A0 reads the values correctly (somewhere between 0V-5V) from the potentiometer which I am varying and D8 will read either depending on the into I give it. But then the values displayed on the front panel may jump to anything between 0-500 in some cases and will fluctuate in that range even when I am not varying the potentiometer. (Please note everything works fine when wired). And the values read from displayed from pin D8 will no longer read 0 or 1 but will be reading up in the hundreds like the A0 values. Sometimes it will come back and read correctly again but more often than not it won’t. See the below image the waveform graph should display the digital pin output but it is seeing values up to 200V apparently!
The area circled in red in the picture below seems to be where I can see these excessively high values occurring from. As can been seen there is a warning message (ok 1073676294), which on this link (http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/c96c84c922dc3f978625632500482f78?O... ) I am told it is a good warning as it is a positive number!.
The block indicted with the green arrow above is an Index array function and the block to the right joins (concatenates) the numbers in the array, at some point the values in the Index array function seem to get swapped around and the value outputted will be very high i.e. a lot higher than 5V for the digital input.
Attempts to fix:
- I have tried replacing all hardware.
- I have tried changing the Baud rate it seems to have no effect.
- I do however get better results (Runs for longer without giving erroneous readings) when I power the Arduino connected to mains supply compared to the results I get when using a 9V battery.
- I have also tried reinstalling the Bluetooth Stack on my laptop.
- I have outputted the data to the serial monitor in the Arduino IDE and it seems to work flawlessly i.e. no erroneous readings (Code for this is also attached below).
- I have been able to recreate the problem on another machine with labview 2014 using the same Arduino but a different Bluetooth dongle and the problem still exists.
Any suggestions would be greatly appreciated at stage.
I will do my best to answer any questions.
Thanks in advance
Also below is code to read data over bluetooth from pin A0 on the arduino IDE.
/*
Example Bluetooth Serial Passthrough Sketch
by: Jim Lindblom
SparkFun Electronics
date: February 26, 2013
license: Public domain
This example sketch converts an RN-42 bluetooth module to
communicate at 9600 bps (from 115200), and passes any serial
data between Serial Monitor and bluetooth module.
*/
#include <SoftwareSerial.h>
int bluetoothTx = 2; // TX-O pin of bluetooth mate, Arduino D2
int bluetoothRx = 3; // RX-I pin of bluetooth mate, Arduino D3
int analogPin = A0; // potentiometer wiper (middle terminal) connected to analog pin 3
int val = 0; // variable to store the value read
SoftwareSerial bluetooth(bluetoothTx, bluetoothRx);
void setup()
{
Serial.begin(9600); // Begin the serial monitor at 9600bps
bluetooth.begin(115200); // The Bluetooth Mate defaults to 115200bps
bluetooth.print("$"); // Print three times individually
bluetooth.print("$");
bluetooth.print("$"); // Enter command mode
delay(100); // Short delay, wait for the Mate to send back CMD
bluetooth.println("U,9600,N"); // Temporarily Change the baudrate to 9600, no parity
// 115200 can be too fast at times for NewSoftSerial to relay the data reliably
bluetooth.begin(9600); // Start bluetooth serial at 9600
}
void loop()
{
if(bluetooth.available()) // If the bluetooth sent any characters
{
// Send any characters the bluetooth prints to the serial monitor
// Just informational
Serial.print((char)bluetooth.read());
}
// Simply read the value and print it out via println. This will send the value as ASCII
int analogValue = analogRead(analogPin);
bluetooth.println(analogValue);
// Also prints it to the serial monitor, just informational
Serial.println(analogValue);
}
Hi qzerror , thanks for your reply.
I was not entirely sure "poll the analog and digital pins sequentially". I have attached a VI of what I think you meant for me to try.
However the error still presists with this VI, see image below.
However my forementioned setup did work previously and I'am in the debugging process. (With no end in sight!)
Any further suggestions/ help you could provide would be much appreciated.
Thanks.
Hi ArtG
Thanks for your help,
I am looking into LINX, I set it up to read an analog pin (A0) over USB.
This seems to work fine.
But do you have any information on how to communicate this pin reading over bluetooth?
I have uploaded the firmware for serial commnication (the only option) to my arduino.
I have the bluetooth module( https://www.sparkfun.com/products/12576 ) connected to my arduino and paried with my PC, it shows as COM40 in device manager.
I assumed AI channel corresponds to the Analog pin on the arduino (A0 in my case)
But I get the following errror.
Do you know how to ensure labview can read the data from com40?
Is there a change to be made ot firmware?
Any further suggestions or help will be much appreciated.
Thanks
