Having a couple of issues with what I was hoping to be fairly straight forward.
I've been transmitting data from my PIC to a PC via RS232 at a baudrate of 115200. I've recently got a RN-41 bluetooth module and was hoping the switch would be as simple as powering the module and connecting the PIC TX (via a max3232) to the RN-41's RX, as the online community has led me to believe.
I'm able to connect to it and pair it to the computer, I'm also able to use PUTTY/Realterm to change the parameters, like the name and baudrate. Finally, by connecting a link to the RX and TX on the bluetooth module and powering it, I'm able to ping text by sending and echoing it using PUTTY, so I'm fairly sure the module isn't broken.
However, when I try to transmit my data from the PIC to the bluetooth module, and view it using realterm (which was working fine with the wired connection) I'm getting data received, but it's not what is expected. I'm expecting a packet of 25 bytes, with a header value of 2, I'm getting around 12-15 bytes and a header of -65.
The first value, -65, is always the same, and the other data can change, which really suggests a baudrate problem, but I've tried a variety of baudrates (changed in my UART code, the bluetooth parameters, and in realterm), and the data doesn't change at all; always wrong.
What have I missed? Anything I need to change in the Bluetooth configurations? I've also checked the parity bit, stop bit, etc, all the same as each other.
The problem was the MAX3232 circuitry. It was necessary for the RS232 connection I was using prior, but when I wanted Bluetooth, which required TTL signals, I was feeding it the same RS232 data!
Making a link straight from the PIC to the Bluetooth receiver solved this problem. Hope this helps someone else in the future!
Related
I am a beginner to arduino and trying to follow one of the videos from youtube to make a project- Master And Slave using HC-05 modules. I followed every step from that video carefully. Here's the link to the video ->
https://www.youtube.com/watch?v=BXXAcFOTnBo
For Slave Module when I type AT commands in the serial monitor nothing shows up.
I searched in Internet for the this problem and still didn't fix it. Here's What i have done:
tired restarting my pc
tried Changing arduino, At first i used arduino nano and then uno
I tried changing the baud rate to all other values and nothing happened
And there is no change in light blink, it stays on AT command mode until power is turned off and on again.
This is how is looks
Thank You For the Answer
Your problem is not actually related to arduino in any way. This tutorial is utilizing onboard USB->UART transceiver IC. So in theory you could even remove Atmel chip from the board. Its more like using module like this FT232 converter. Anyways sorry if I confused you but you can research the subject.
But anyways to the problem. Couple of questions:
Did you press reset button on module while powerin up the circuit?
Thats the way it enters to AT command mode
Did you try to reverse RX-TX lines, don't worry connecting these guys across eatch other doesn't harm your board.
(They are so often plugged in wrong..)
Did you make sure you have connected EN pin of module also. (To arduino 3.3V not 5V)
Did you triple check all connections
Try to upload simple Sketch like blinky to Arduino to make sure you are connected to USB-UART transeiver and you have correct drivers.
Make sure you upload empty sketch or remove the chip when you try to apply tutorial steps.
Change jumper wires. Sometimes cheap jumper wires are really bad quality.
I have been sometimes scratching head for long time because of broken jumper cable.
Please let me know if you have checked all of those so we can think for next step.
I am currently working on a project which aim to detect Bluetooth and decode Bluetooth packets (I use a Hack RF One to make the detection). I have made a Gnuradio Flowgraph in order to demodulate Bluetooth signal and I am trying to decode visualy the packets by searching a Bluetooth frame on a binary file.
Unfortunately, I didn't succeed to recover a clear view of the Bluetooth signal. To be precise, I am pretty sure that I detect Bluetooth on my sinks but when sending this to a Clock Recovery + Binary Slicer blocks, I am unable to recover interresting data in the binary file (especially the MAC adress of the sending device, which is part of the a Bluetooth packet). Moreover, I would like to know what type of network layer (physical, transport, baseband...) is intercepted in this type of process. In my case, I aim to intercept baseband layer packets.
Additionaly, I am interrested in knowing how to use the gr-bluetooth because I can't find a lot of documentation concerning this block. I think this can be interresting for the development of my project.
Could you please, give me your view, opinion about this problem ? I am stucked at this stage without knowing the exact origin of my issue. (Here is my flowgraph GnuRadio_Flowgraph and a screenshot of one of my Bluetooth detection Detected signal at 2.402GHz).
Thank you very much,
You probably need an ubertooth instead https://www.sparkfun.com/products/10573
I read that the bluetooth frequency skipping is spread wider than the HackRF can read, so at-best, you're going to miss 75% of frames if you only have one hackrf connected.
I'm trying to get data from a mercury analyzer (Seefelder-Messtechnik Hg Analyzer 3000) that gives output to a 9-pin R232 serial port to my OSX 10.10 laptop.
I've followed the steps described here to install the PL-2303 driver:
http://pbxbook.com/other/mac-tty.html
The device manual (http://www.seefelder-messtechnik.com/V71-3-02-21e.pdf) lists the communication protocol as "9600 Baud, 8 data bit, 1 stop bit, no log,
no parities".
I attempt to read from the device by using the 'screen' command:
screen /dev/tty.usbserial 9600
The result is a string of seemingly non-sensical characters that print to the screen in a regular interval:
�8b4����b��8b48bs��8G�8b�8���8������8����< 8�8��b��KW��\b����8b����b� �b�b����KW�K �8b��\G�� �<���8�8b�"���[��؉���bG�3�ˁ�G��\K��[W�pb�8��8ʱ�\pa���ʁ�c t��8�h¡�38b�8�q�����\�8���bS�8b8�8�q���X��8��<��£8���2�8�����ؖ�ؖ�ؖ�8bS��\�܉�ؖ����[S�8��s���fq�8�����������8fq����������S�܊��b���b�؉����\���S��K���ݎ����S��b��b��S����S�\������KS��S�؊��\S�1S�\b�S�؉�\�ذ����KS�\����S����bS�؉�����1S�؊��[����ز������؉\���ز��\����i���$\�$���\��8���$��\�\����܂�زXk�B��7��\k�\X�<��8Xkz��Yj��L�������H�\���]j�،k:��Yj�؈��
I've also tried using 'minicom' rather than screen, and get a different ("?]???ܰ??Yk??2"), but also non-sensical result. I saw that there was another SO query similar to mine that remains unsolved: weird characters displayed during serial communication OSX
Any tips? It looks to me that I'm not interpreting the output correctly, but I don't know what to try next.
The solution was to read from the machine at a higher baud rate (~57600), despite what the manual and online reference said. Reading at 57600 baud made the result plain-text and usable. Thanks for your ideas!
I've followed the steps described here to install the PL-2303 driver
I've also had occasional electrical ground problems with Prolific USB-RS232 adapters. Problem would manifest as garbled data that looked similar to a baud rate issue or what you posted.
You can check if it's a ground issue by measuring for continuity between the ground pin (pin #5) on the DE-9 (aka DB-9) side of the Prolific adapter and the ground pin of the USB side (pin #4, "far left", of the A connector). You'll probably measure infinite resistance with a multimeter. Try the same with a FTDI USB-RS232 adapter, and instead I get a dead short between the ground pins as expected.
Be sure to plug the instrument's and PC's power supplies into the same power strip.
As a last resort try grounding the instrument's chassis/case with the PC using copper wire
I'm working on a project with Android and Arduino and am trying to figure out how on the Arduino side to tell if the Bluetooth is connected or not.
I'm using one of these Bluetooth Modules to connect. I know I can send a command through Android, but I'm trying to have an action happen automatically when they connect and not have to run a background application on the Android if possible.
Using the module supplied and nothing else you cannot: notice the module has four connectors:
Power (Vcc)
Ground
Tx (send)
Rx (receive)
Given this interface the only way to determine whether the bluetooth module is paired is to send something to the paired device and have it respond in such as way that your Arduino knows that it is connected. For instance, if your Android program always responds with "Hi there!" when it receives a string "Hello?", then by seingin "Hello?" your Arduino will know that it is paired with your Android phone/tablet. Your Arduino could poll (send the interrogation string) every minute (or every five seconds) to see if it is paired with your device.
There is a better way, but it will require some soldering on your part. If your module is HC-03/HC-05-based, then the PIO9 pin is the "paired indicator LED" (see datasheet here). You could connect that pin to an Arduino input pin and read the level: reading digital 1 will indicate that the device is paired, while reading digital 0 will indicate that it is not. It is possible, though not certain, that the pin on your module labeled STATE is exactly this kind of a pin, i.e. it indicates the paired status. Unfortunately. this pin it isn't connected to the header, so you'll have to solder a wire to the correctponding pad to connect it to your Arduino. You should test it first by connecting a multimeter in voltage mode to that pad and measure the potential between that pad and ground in paired and non-paired state. If this is the pin that responds to the paired state then you are golden. It might be that it indicates power (like the HC-03/05 PIO8 whilc blinks when on). If it turns out that the STATE pin is not the pairing status, then you should request a datasheet from your supplier, and use that to find the status LED connection: one is likely to exist. Once you found the correct pad, verify its function using the voltmeter again. Then solder a wire to that connection and read it from your Arduino.
IMPORTANT: Make sure that your Arduino never puts out a digital 1 on the Arduino pin connected to the bluetooth module status pin: these bluetooth modules run on 3.3V, and connecting any unprotected pins to 5V will be damaging. The Vcc and Txd pins are voltage shifted in the module you bought, but the LED/Status lines are likely not to be. So if the Arduino pin connected to "status" on your Bluetooth module is configured as output and you digitalWrite(HIGH) to it, you will likely damage the Bluetooth module.
Unfortuntaely, the HC-05 will switch states when paired, but won't output a 1 until it's actually connected to something.
For instance, I can unpair my phone from the HC-05, pair again, and then the LED will change state, but the output of the STATE pin is still 0. If I open up an app, and connect to the device manually then the LED, and STATE pin will change state. The LED will periodically blink twice, and the STATE pin outputs a 1 to the Arduino.
If you would like to read the the value of the STATE pin, connect a wire to any of the inputs to the arduino, and code Serial.println(digitalRead(inputPin)); inputPin being the wire to the input of the Arduino.
I've been fighting this thing for months, and have yet to find a way to make this thing automatically connect to my phone. It won't even allow for me to connect to it from my phone to the HC-05 unless I download an app onto my Android. It's possible to bind the HC-05 to a certain address, but even this did not work for me. I want to mess with the "AT+CLASS" command, but the documentation behind the instruction has hindered me thus far.
From the HC-05 datasheet we see that the connection status depends on the output from PI09. Apparently sending "AT+BIND?" to the module will return the status of PI08 & PI09 in the form,
"+ POLAR=PI08,PI09" however this makes no sense to me because in order to get this you must enter AT mode and entering AT mode will disrupt the paired connection, hence it will always send PI09 marked as "not connected".
THUS in order to see if the connection is still live from the arduinos POV I can only see 2 feasible ways:
Program arduino to, every so often, send a "hello?" and if it doesn't receive the expected "Hi back" response, then it is to assume that it isn't connected.
Connect PI09 to an arduino input pin and read it's value whenever you want to check if the connection is live or not
AT+STATE? will return the current state of the connection. Yes you will need to enter at mode, that is done by bringing up pin 11 HIGH on the HC05 module. It does require soldering but it's kinda worth it. It then allows full AT control of the device, then set it LOW to return it to normal working mode.
Another option, which I don't fully understand, is the AT+MPIO? command, which returns the state of all the pins in some strange masked format I don't understand yet.
I use the first option above so that I can terminal (Bluetooth) from my phone to the HC05 and switch on a led/relay etc (ie bring up pin 2 to HIGH) on the HC05. This required entering AT mode (pin 11 HIGH), sending the command AT+PIO=2,1 and then setting pin 11 to LOW to return to normal working mode.
Note: I noticed I had to put a 200ms delay in between high and AT and LOW commands. Angela's solution is nice - I use a cheap XBEE Bluetooth module (HC-05 Bluetooth Bee Master & Slave Module with Bluetooth XBee for Arduino uk2015) 2 units(HC05/6) for 5Stg which are laid out in XBEE format - handy for the 3.3v.
Hello there I am a newbie trying to prove the working of RS 232 Full modem and also one RS 422( RX,TX,RTS,CTS)
These 2 ports are on a custom designed board and I need to prove they are working.
I am able to confirm the working at register level but I need to prove the working using softwares like Minicom or any other custom program.
How can I prove the working of these ports from one PC to a different PC using DB 9 connections and LOOP BACK too
Can someone help me with this? Do I need to use any extra hardware to prove the working of this in Linux?
The most common type of serial port test is probably a loopback test. Create a test fixture that connects output pins of the port to the input pins (TX->RX, RTS->CTS, etc). If you do not have matching input pins for every output pin, you will need to do a three-way connection.
After you create the loopback, you will need to write software that exercises the pins. If TX and RX are connected, you can send a byte and verify that it was echoed back. For the control pins, toggle them and make sure the other side of the connection saw the transition. Make sure you exercise every pin of the serial port.
Note that you should run a TX->RX data loopback at multiple baud rates. It is possible for there to be a signal integrity issue in the design that only shows up at higher bauds rates. It is also possible for there to be a bad signal connection on the board that is masked by inductance and capacitance at higher baud rates. Therefore, it is a good idea to run a data loopback at the slowest baud rate, the fastest baud rate, and 1-2 in the middle.
Another thing you should do is a baud rate accuracy test. This will prove the clock driving the UART is running at the right frequency, and being divided properly. Transmit X amount of bytes at a certain baud rate and verify they arrived in the expected amount of time. To get an accurate number, you will need to bypass any buffering in the OS serial port driver (e.g. use direct register I/O), and make sure to accommodate for any start/stop bit overhead (see comments below).
However, a loopback test is not exhaustive. It only proves the device can talk to itself. The device may still have some flaw (e.g. voltage levels) that cannot be detected locally. So, you should also run some tests with external hardware. Cable your board to another system and run a test (e.g. with minicom). Make sure they can talk to each other.
Even an external communication test can miss something. You can still have poor signal quality from your board, but it happens to be good enough for the other device. To accurately verify the signal quality/timing, you need an oscilloscope.
While you are running communication tests, connect the scope probes to the various signals and verify the signal integrity. Make sure that voltage levels are valid, that you see clean low/high bit transitions, and that the timing of the data pin appears correct for the specified baud rate. (A scope can be a more accurate way to measure baud rate than the software-based method described earlier.)