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 buffer to match the tag and you don't have to repeatedly search for the string in the buffer.
const char* TAG_STR="(__BOOK_UPLOAD_START__)";
int tag_pos = 0;
I've always used flag to indicate a boolean logic value. I would also suggest this is an archaic term.
Was going to come up with my own explanation but found the following at In C language, what does flag mean?:
A 'flag' is a variable that is supposed to signalize something. Think
about the word itself - flags are used in sending signals. In our
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 short one.
AT+INQ will provide you with a list of nearby devices, to which it can connect.
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 data using Bluetooth SPP-C Module without a Breakout-Board. I tried both SPP-C and HC-05 with and without breakout boards finding the same issues. So if you are ...
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 simply have each byte as a 1:1 mapping to a PWM value.
One the transmit end:
On the receive end:
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 memory on a Uno by commenting out the macro(s) in MCUFRIEND_kbv.cpp
So you open MCUFRIEND_kbv.cpp and comment out support for the controllers you aren't using.
I assume you mean that are running short of flash memory, rather than
RAM. I base this assumption on the fact that you say that it's 99%
full, and that this “is not very troublesome”. Filling 99% of the RAM
with statically allocated data would certainly be troublesome. But
please note that it as always better to make your question clear and
explicit, rather ...
answer on your comment on Majenko's answer:
(cannot comment due to reputation)
build a simple web server on your device and make sure it is accessible from a local network node (e.g. a PC).To do this open from a web browser the page ip:port where ip is the ip assigned to arduino (usually from your router's DHCP service) and port is the port which your web ...
Your options are:
As you guessed, you could set the name with AT+NAME=, and only use the names matching some pattern. It would work if you're only user so you just want to ignore other BT devices, but is problematic if you're having multiple independent users (each with its different set of *HC05*s) who might be in range (you could set different pattern for ...
You just have to send the above Bluetooth command via serial port to your Bluetooth module using print command.
For example yourserial.print("AT+BIND?"); OR yourserial.print("AT+INQ"); if you are using SoftwareSerial. Otherwise just use Serial.print("AT+BIND?"); OR Serial.print("AT+INQ"); when using Rx/Tx pins. That will do the job.
The HC-05 uses the Bluetooth Serial Port profile (SPP). The PS4 controller doesn't.
Hence you need something that is capable of using the same profile that the PS4 controller uses (HID?). And to that end you need something a little more configurable than a simple HC-05. One option is, as most people use, a USB Host shield with a Bluetooth dongle that can ...
You can (just about) use any combination of two of:
Serial to PC,
You have, basically, a hardware UART (pins 0/1), and a software UART (any pins of your choice).
Only the hardware UART can be used for communication with the PC, and you can only reliably use one instance of SoftwareSerial.
So, you could:
Use Serial to the PC (0/1) and HC-05 (...
I had the exact same problem and got it to work doing these changes:
I had to add this under my library include statements
#define D5 (14)
#define D6 (12)
#define D7 (13)
#define D8 (15)
#define TX (1)
SoftwareSerial BTserial(3, 1); // RX, TX
I used D5 and D6 on my ...
I am using a "BIND" between the PAIR and LINK:
That seems to work for me.
See the docs here:
6F22 (PP3) batteries are among the wimpiest of batteries available. They are not a good choice for anything except extreme low power applications, and anything involving radio transmitters is definitely not an extreme low power application.
Use a better battery. I would recommend 6 AA batteries (you can get 6xAA battery holders with the same connector as ...
Unless you've manually set the btSerial speed, you need to be at the default for AT commands which is 38400 -> btSerial.begin(38400);
If you want to read regular Serial communication, you'll need to monitor 9600 -> btSerial.begin(9600);
If you are unable to to send commands, I feel as if you wouldn't have changed the default speeds.
I used this link as a ...
first of all just to clarify some things.
softwareSerial library sets PinMode for rx,tx declared pins internally so it should not have any impact on voltages you measure if you include pinMode(bluetoothTx, INPUT); and if this happens, as you describe, it indicates a problem.
a pin declared as INPUT is on a high impedance state which means that it will not (...
You can switch between command and "online" modes, but you cannot use both at once. While in command mode you can't be receiving data, and while in online mode you can't be sending commands.
You would have to periodically switch between the two in your program at a time when you know you won't be receiving data (or you don't mind losing that bit of data).
Receiving serial characters is partially done in hardware and partially in the Arduino firmware.
The only thing you need to do here is:
- check if you've received a full message.
- handle the message (if a full message has been received)
For the ultrasonic sensor, you'll have to:
- Start a measurement.
- wait for a response.
- convert the response.
I suppose you're referring to the HC05 module, already soldered on a board, with the 6-pin header. The regulator is on that board.
Online you'll find several versions of that board, therefore you should check the schematics, to find which you need to mount. For instance, on some board, a R1114-33 is used.
Changing the regulator is not the hardest task on ...
You need more power!
The formula for power is Volts * Amps. A PP3 has about 500mAh, which means its can (in theory) output 9V at 500mA for an hour, which means you have about 4.5 watts.
So what power do your motors need? I'll assume they are about 1.5W motors, which means you need 6W to drive all the motors.
Your PP3 can output 6W, but it won't last long ...
That's not a good choice of MOSFET I'm afraid.
The on resistance is quoted as 14Ω when the gate is at -10V - however, you are only able to get -5V, so it will be considerably worse.
That massive on resistance will be causing a massive voltage drop, which is what you are experiencing.
You should find a MOSFET with an on resistance that is in the milli-ohm ...
It is unlikely this module got a virus. It sounds more like a data rate mismatch or a noisy connection.
If you get ONLY the strange characters and nothing that you would expect, even in part, then confirm that the serial port speeds are equal on both the Arduino and the HC-05 module.
If you get some expected data, with junk characters mixed in, then check ...
I did something similar (multiBT) using HC-05 and PC BT, with the same App.
Results: all the incoming data from the PC_BT to the phone are right, but with the HC-05 sometimes is chunked as @deostrol show. I think is a bug with the HC-05 firmware.
To correct this, I've implemented StartBegin and StopFinish character in the received string before use.
Serial.read() returns -1 if no data is available. It doesn't wait for the byte. Test for -1 or use Serial.available() as any example does.
Replace Serial.print(data) with Serial.write(data) to get the data echoed back unchanged.
Actually got it working myself, but thank you so much for your help @chrisl
Ditched the for loop completely just to try things out and reorganized my code a bit. Surprisingly it started to work well enough.
Basically just moved my measuring stuff outside the while loop*(and now that I think about it, why would it ever be withing the while loop? Literally ...
No, they do not need to match.
You are talking about two separate serial port connections.
The baud rate between the HC-05 and the Arduino (BTserial) has to match.
The baud rate between the Arduino and your PC (Serial) has to match.
BTserial and Serial can use different baud rates.
An overflow problem can arise if a lot of data arrives from the HC-05 ...