communication

问题 I've made an app which connects to Arduino Mega 2560 by means of HC-05 Bluetooth module. I succeed in giving commands to Arduino via bluetooth, but the opposite communication doesn't apparently work. I don't know if the problem is in Arduino or Android side. Arduino sends messages with this simple instructions: #include ... SoftwareSerial bluetooth(12, 11); void setup(){ Serial.begin(9600); bluetooth.begin(9600); ... } void loop(){ ... bluetooth.listen(); while (bluetooth.available() > 0) {

问题 i would like to send a stream of bytes to a serial port using the command line. is this possible? my serial port is at /dev/cu.usbserial-A700dYoR on my Mac. for example, if i wanted to send the integer 50 or the string "data" to that serial port, how can i do that? my knowledge of UNIX is very limited. 回答1: #!/bin/bash # Port setting stty -F /dev/cu.usbserial-A700dYoR raw speed 9600 echo 'Hello' > /dev/cu.usbserial-A700dYoR or something like that if I remember correctly... Been a few years.

问题 If I am to send a message to a mobile device from a website and viceversa, how can that be done? What I know: A couple of years ago I developed a simple enrollment system on J2ME platform(just for trying J2ME out). I had a mysql database that I setup in a pc/server, and for the communication I used the static IP of that server. I had a bridge, a mobile phone which was connected to the internet, where clients would send a formatted message. That bridge then would send the message to the server

问题 I am using BluetoothChat code on the Android side to send an ON/OFF signal (I am sending 110, 119 or other cases as defined below) to the Arduino UNO using the chat box, but when I display the received value, it shows strange values in the Arduino Serial monitor, that is, 255, 254, 250 or 245 and replies with strange values on the Android side too. but suprisingly only single condition among 110, 119, etc gets true when i send these commands from android and no other instruction/LED gets

问题 I'm revisiting a communications protocol parser design for a stream of bytes (serial data, received 1 byte at a time). The packet structure (can't be changed) is: || Start Delimiter (1 byte) | Message ID (1 byte) | Length (1 byte) | Payload (n bytes) | Checksum (1 byte) || In the past I have implemented such systems in a procedural state-machine approach. As each byte of data arrives, the state machine is driven to see where/if the incoming data fits into a valid packet a byte at a time, and

问题 What would be the best method to achieve realtime device to device communication within an application? I've been experimenting with the Apple Push Notification Service but find it spotty at best for realtime messaging. Is there a way to utilize sockets for this or am I just stuck into using the APNS? 回答1: If you are a beginner, use GameKit. When you get sick of that, use AsyncSocket. GameKit is so simple a child can use it; AsyncSocket is probably the most beautiful library in all of

问题 I've recently decided to take on a pretty big software engineering project that will involve developing a client-server based application. My plan is to develop as many clients as possible: including native iPhone, Android and Blackberry Apps as well as a web-based app. For my server I'm planning on using a VPS (possibly from slicehost.com) running a flavor of Linux with a MySQL database. My first question is what should be my strategy for clients to interface with the server. My ideas are:

问题 Has anyone successfully talked profibus from a .NET application? If you did, what device/card did you use to accomplish this, what was the application, and did you use any kind of preexisting or available code? 回答1: We've not used Profibus, but have used DeviceNET (another CAN based protocol), Ethernet/IP and ControlNet which all have similar challenges. We've been doing this since the late 1990's and therefore rely mainly on our own generated code using off-the-shelf hardware. The companies

问题 I want to create a bridge which can communicate between my C# application and extension. Here is the explanation of what I actually want: I have created an extension which will get details of HTML element. But starts every time I start Chrome. Instead of doing this, is there any way I can send a message to my chrome extension to get HTML element details and then send it back to C# application? I am able to pass information to C# using 'XMLHttpRequest' but issue is, it got started when my page

问题 I am developing a program to communicate with an old system. I use System.IO.Ports.SerialPort for this. The problem is when I send a longer message, the message bevome corrupt. I use a line listener and get the following results What I sending aa 01 00 00 12 03 06 18 02 c1 94 02 c1 94 00 00 00 00 00 00 00 00 00 00 00 00 1e fd What I get c2 aa 01 00 00 12 03 06 18 02 c3 81 c2 94 02 c3 81 c2 94 00 00 00 00 00 00 00 00 00 00 00 00 1e c3 bd The code I'm using is _comPort.Encoding = new