pc sender nxt with nxc receiver

[Bartłomiej Drozd]

Hi.
I need to make one-way communication between pc and nxt brick. I do simple program at pc to send string to brick and program in nxc to receive that string. It’s ok, but i can only one send string to brick, after that brick doesn’t want to receive next string. I use that in c#

string command = Console.ReadLine();
 brick.Mailbox.Send(command, Box.Box0);

and that in nxc

string a;
 while(true)
 {
  ReceiveRemoteString(0, 0, a);
  TextOut(0, LCD_LINE2, a);
 }

when i do program in nxt-g it’s work fine, but i must to do it in nxc. Please, help me with this

[Anders Søborg]

Hi

I think that your problem is already described in this post …

Hope this helps

Anders

[Bartłomiej Drozd]

Unfortunately, that not solved my problem. I send from pc string to mailbox 0 and in brick i receive string from mailbox 0. First time that work great, but when i try to send next string to the same mailbox that didn’t work. When i close program in brick and run it again, then i can again send one string and it’s a loop… when i do program in nxt-g i send from pc string to mailbox 0 and receive in brick from mailbox 1 and that work fine. I don’t know what is wrong

[Anders Søborg]

Hi

Ok since it is working in NXT-G – there must be a problem in your NXC code… what does the docs say about

ReceiveRemoteString(0, 0, a); ?

Anders

[Bartłomiej Drozd]

but when i do second sender program in second brick work fine at the same mailbox.

ReceiveRemoteString(queue, remove, out strval)
This method is used on a master brick to receive a string value from a slave device
communicating via a specific mailbox or message queue. Optionally remove the last
read message from the message queue depending on the value of the boolean remove
parameter.

[Bartłomiej Drozd]

Or maybe You could help mi with c++ library? I need to make one-way communication pc -> nxt with camera vision and i have finished program to camera vision in c++, without communication between pc and nxt. I need to send some string messages to difefrent mailbox. I don’t know how to use Your c++ library to send bt or usb messages to default mailbox

[Bartłomiej Drozd]

ok, i solved this problem. I noticed, i must to send 5 times the same string to nxt, then nxt receive it correctly.
In c# it’s look that:

bool f = true;
Console.WriteLine("Y: ");
data = Int32.Parse(Console.ReadLine());
command = data.ToString();
if (f == true) //because first time send correctly
{
  brick.Mailbox.Send(command, Box.Box1, false);
  f = false;
}
brick.Mailbox.Send(command, Box.Box1, false);
brick.Mailbox.Send(command, Box.Box1, false);
brick.Mailbox.Send(command, Box.Box1, false);
brick.Mailbox.Send(command, Box.Box1, false);
brick.Mailbox.Send(command, Box.Box1, false);
brick.Mailbox.Send(command, Box.Box1, false);
Console.WriteLine("Y pos: " + command);

[Anders Søborg]

Hi

I think that this is a timing issue… It seems wrong that you need to send the same string five times – this is not a fix. Like I said there must be something that you are doing wrong in your NXC program since the NXC code and NXT-G compiles to the same byte-code….

I can’t remember NXC but does strings in NXC have variable length? or do you need to specify the length when you create a string?

Anders

[Joshua Peterson (jpcreeper13)]

Can you send me the project file so I can use it?

• This reply was modified 7 years, 10 months ago by Joshua Peterson (jpcreeper13).

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