I have built an android app that will send a string of values (using getbyte()_) across a serial connection. I would like each of these values to be stored in a seperate variable/
For example:
a list of numbers like this:
10004056700003
are sent across the connection.
there are a bunch of variables on the arduino side:
A,B,C,D.... etc
i would like to be able to do this:
A = 1
B = 0
C = 0
D = 0
E = 4
F= 0
.... and so on. i will then use these variables to run a certain sequence of functions on the arduino. In this sense the android application is just to control the arduino.
Thanks for the help! :D
Serial communication usually happens byte-wise.
So if you want to transfer a sequence of numbers (>255) the easiest way is to send each digit as a byte.
On the receiving end you basically have two options.
a) you read each byte and do something with it befor reading the next byte.
b) you read the bytes into a buffer array and do something with it later.
If you want to minimize the number of bytes transferred you of course can split the number value into several bytes instead of transferring each digit.
Try sending the data as String, and then you can access each character of the String using the method: StringVariableName.charAt(pos);
With this approach, your code will be more readable.
Check out charAt function here.
Related
I am trying to get information from an Excel worksheet and send it through a serial port as a byte array, using Windows API. This is just a small part of it:
lngSize = UBound(byteData) - LBound(byteData)
WriteFile(udtPorts(intPortID).lngHandle, byteData, lngSize, _lngWrSize, udtCommOverlap)
My current problem: when I am sending a byte array of length 1 (just one byte), I receive it correctly (I am using a hyperterminal to check what I'm sending), but when I send an array of length > 1, here comes the problem; instead of receiving it like this:
letter = 65
For i = 0 To 5
dataToSend(i) = letter
letter = letter + 1
Next
what I should receive
what I get is this:
what I receive
I really cannot figure out what could be the problem and I would be grateful if someone had a clue. Thank you!
First, the correct number of elements in an array is:
lngSize = UBound(byteData) - LBound(byteData) + 1 ' <-- add 1
More importantly, your code is not applying the call convention for the WriteFile API. Namely, the second parameter should be a LPCVOID pointer to the first Byte to transfer. Passing the array's name byteData to the function wont achieve that, because the array is a complex COM data structure, not like a C array. What you should do is:
First get the address of the array's data structure, using VarPtrArray:
Then add 12 to it to get the address of the first byte.
.
Private Declare Function VarPtrArray Lib "VBE7" Alias "VarPtr" (var () As Any) As Long
...
WriteFile(udtPorts(intPortID).lngHandle, VarPtrArray(byteData()) + 12, lngSize, _lngWrSize, udtCommOverlap)
' ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
For information about handling arrays' data and their pointers, excellent examples can be found [on this page].(https://www.codeproject.com/Articles/729235/VB-and-VBA-Array-Buffering)
Also make sure that you declared you array as a Byte array, like
Redim byteData(someSize) As Byte
' ^^^^^^^
There might be other errors in the parts of code you didn't show (possibly the settings of udtCommOverlap), but hopefully these corrections will put you on the right track.
I am trying to get and send my MCU's IP Adress, SubnetMask and Gateway adress.
I got them but problem is merging them. I want to merge them with array and send for one step..
For example:
my values are
e2promIpAddress = 0A020705 // represents 10.2.7.5
e2promSubnetMask = FFFF0000 // represents 255.255.0.0
e2promGateway = 0A02070F // represents 10.2.7.15
When I add with sprintf()
char buffer[64];
sprintf(buffer,"%x%x%x",e2promIpAddress,e2promSubnetMask,e2promGateway);
Output is A020705FFFF00000A02070F
Unfortunatelly array must start with 0 but it goes away..
Thanks in advance
I finally find my answer and want to post here..
My values for example e2promIpAddress = 0A020705 is 4 bytes.
When I wrote this with;
sprintf(buffer,"%02x%02x%02x",e2promIpAddress,e2promSubnetMask,e2promGateway);
it did not pad "0"
when I wrote this with;
sprintf(buffer,"%08x%08x%08x",e2promIpAddress,e2promSubnetMask,e2promGateway);
all values which starts with "0" pad with "0"
Have a good day..
I Have Antivirus Form
i want scan the application running and found the md5 hash and not the process (only MD5) and i want do some action if the md5 same with my TextBox, anyone can help me how to do that?
Thank you before
Sorry for my bad english.
you can get the filename by making an array of the running processes
Then you can build a function that does an MD5 of all processes found.
Maybe if you split your idea into many small chunks you will get forward easier.
I'd try to create an array of the processes and their paths (see my snippet).
Then you can write that to another Array where you add the checksum that you calculated in the line and use a split-character like ";"
So one line of your array could be "C:\windows\system32\cmd.exe;afd4383f8d8fd"
Then you can loop through the processes, do an MD5 of your process and then look it up in the array you wrote, it will lookup the Filepath as ID and then it will compare the MD5 in the array with the one you calculated again.
When you put that on a timer with a tick of like 5 seconds you could kind of "seal " your application-sums and let a warning appear if there is a mismatch or something else.
Dim Processfinder() As Process = System.Diagnostics.Process.GetProcesses()
For Each pr In Processfinder
Dim Prstring As String = pr.StartInfo.FileName.ToString
Next
Since i built something similar a while ago:
You have to be aware that you cannot see all processes if your program is 32 bit and your OS is 64 bit.
I'm currently using Erlang for a big project but i have a question regarding a proper proceeding.
I receive bytes over a tcp socket. The bytes are according to a fixed protocol, the sender is a pyton client. The python client uses class inheritance to create bytes from the objects.
Now i would like to (in Erlang) take the bytes and convert these to their equivelant messages, they all have a common message header.
How can i do this as generic as possible in Erlang?
Kind Regards,
Me
Pattern matching/binary header consumption using Erlang's binary syntax. But you will need to know either exactly what bytes or bits your are expecting to receive, or the field sizes in bytes or bits.
For example, let's say that you are expecting a string of bytes that will either begin with the equivalent of the ASCII strings "PUSH" or "PULL", followed by some other data you will place somewhere. You can create a function head that matches those, and captures the rest to pass on to a function that does "push()" or "pull()" based on the byte header:
operation_type(<<"PUSH", Rest/binary>>) -> push(Rest);
operation_type(<<"PULL", Rest/binary>>) -> pull(Rest).
The bytes after the first four will now be in Rest, leaving you free to interpret whatever subsequent headers or data remain in turn. You could also match on the whole binary:
operation_type(Bin = <<"PUSH", _/binary>>) -> push(Bin);
operation_type(Bin = <<"PULL", _/binary>>) -> pull(Bin).
In this case the "_" variable works like it always does -- you're just checking for the lead, essentially peeking the buffer and passing the whole thing on based on the initial contents.
You could also skip around in it. Say you knew you were going to receive a binary with 4 bytes of fluff at the front, 6 bytes of type data, and then the rest you want to pass on:
filter_thingy(<<_:4/binary, Type:6/binary, Rest/binary>>) ->
% Do stuff with Rest based on Type...
It becomes very natural to split binaries in function headers (whether the data equates to character strings or not), letting the "Rest" fall through to appropriate functions as you go along. If you are receiving Python pickle data or something similar, you would want to write the parsing routine in a recursive way, so that the conclusion of each data type returns you to the top to determine the next type, with an accumulated tree that represents the data read so far.
I only covered 8-bit bytes above, but there is also a pure bitstring syntax, which lets you go as far into the weeds with bits and bytes as you need with the same ease of syntax. Matching is a real lifesaver here.
Hopefully this informed more than confused. Binary syntax in Erlang makes this the most pleasant binary parsing environment in a general programming language I've yet encountered.
http://www.erlang.org/doc/programming_examples/bit_syntax.html
I have scales equipped with RS232 serial port and a Bluetooth transmitter. I made a program in VBA to receive data from the scales. However, lets say out of 10 incoming strings I get 3 distorted. My regular strings look like: "+001500./3 G S". This means 1500.3 grams above zero and the output is stable. But sometimes I get strings like separated like "+" or "001500./3" or "G S". When I plug serial cable I have no distortions.
Serial ports are just byte streams. You can never make assumptions about how many of the bytes will show up on each read operation. It's only coincidence that when you use a real cable you read the whole string at once. You have to do the string splitting yourself, and continue reading when you only get a partial result.