hello i'm new with using RTOS with my board is NUCLEO-G474RE,with my question maybe not clear
well using C# making a GUI to Connect with my board i and sending a value while using RTOS method,
RTOS i have two task there ,Task1 is receive and sendback value that user type also led toggle,
Task2 also is UART receive then flash into my memory,with both task i have send back msg to tell
the task done,the problem is while i send value i cant accuracy flash my value into my board
i have type serval times,i forget to say i only open one uart so i dont think need semaphore
also the GUI i saw the value sendback is right but when i look at the stm32 memory side the value
is ASCII value when i send string is right but sending interger is wrong
fix my question with some pircture sorry i'm new here the picture only show the links
My goal is flash data with uart below is what happen
1.Here is two task ,Task 1 is write the uart receive data into my memory
enter image description here
here is my C# gui when i sending data i send back value
enter image description here
And while i looking at the memory but the data which write in is wrong
enter image description here
I am learning to rewrite the code for the microcontroller integrated in the development Sim modules (such as Sim800C) to be able to control switching a device without having to use another MCU. If we can do that, we only need to add 1 transistor to be able to control a relay on and off.
I know at the output of the MCU (eg STM32F...) inside the sim module (eg sim800C) there will be a function to receive and read personal information stored in the sim card and decode the signal emitted from the Mobile base station: For example, when a call comes in, it will generate the sequence:
RING
+CLIP: "01203360211",161,"",0,"",0
....
So can anyone help me to know when the MCU outputs a string like the above, what will be its input 11110000,...? or something special in some form? I'm really confused. Thanks everyone!
In a professional context, I have to use the vl53L0x. This sensor was released recently, along with it's API, meaning that there's no help on the internet yet :
http://www.st.com/content/st_com/en/products/embedded-software/proximity-sensors-software/stsw-img005.html
This API contains some source and headers file, that I compiled with the gcc. It works fine, despite clearly lacking comments. I flash the memory of a stm32 (NUCLEO-F401RE), which controls a vl53L0x sensor via an I2C bus. I now want to add more vl53L0x sensors on the same I2C bus, and refer to this document (if you want to read it, go directly to the bottom half of the page 5, the wiring is already done) :
http://www.st.com/content/ccc/resource/technical/document/application_note/group0/0e/0a/96/1b/82/19/4f/c2/DM00280486/files/DM00280486.pdf/jcr:content/translations/en.DM00280486.pdf
The principle, that I already applied on other sensors, is that they all start with the same address. You then have to activate one, change it's address, then activate the next one, change it's address, etc.
Unfortunately, ST Microelectronics didn't publish the list of the I2C registers, so I have to use their API to control multiple sensors. The document linked above explains how to do so. Among other things, it specifies :
In vl53L0x_platform.h API file
• Set VL53L0x_SINGLE_DEVICE_DRIVER macro to 0 so that API implementation will
be automatically adapted to a multi-device context.
I looked everywhere in the API folder, I was not able to find any reference to a VL53L0x_SINGLE_DEVICE_DRIVER macro. Setting it to 0 won't change anything, as this string is not present anywhere in the API files. Did anyone run into a similar problem ?
I'm working on the same thing. It seems that you're further ahead than I am. However, putting this in my while(1) loop seems to make both the sensors work.
ResetAndDetectSensor(0);
TimeStamp_Reset();
The guide says that in order to use all the sensors simultaneously, you need to pull the XSHUT pin high for all the sensors, reset the timestamp and then pick up the sensor which actually detects something.
I want to create a list of names on my Arduino. I want to be able to add a name to the list, I want to be able to remove a certain name from the list and I want to be able to check if a certain name exists in the list.
As far as I understand I need to use something called EEPROM?
BTW. I might gotten something all wrong, please tell me.
EEPROM means programmable for multiple times. Not mean storage. If you want to store list while the device is running, it is possible. Define an array like standard way. You can search in that array, add names to array by using arduino console. These are depends on your code.
But if you want to store your array all the time (even device is closed) you need a storage device such as sd card or something like this.
It is possible to store data in the EEPROM, but depending on the Arduino model there isn't much space. You would be better off using an SD card shield.
I want to write a client program that communicates with the application server via standard TCP/IP. The client can speak to the application server and be authenticated by simply speaking in a specific text based protocol. The traffic will be encrypted, but there won't be username/password. If another application tries to communicate with the application server and if the application doesn't use the correct text based protocol, the application server will silently discard packets.
Waiting for suggestions.
You can use a simplified version of TLV (Tag Length Value).
The basic idea is to define a set of message types which are represented by a code of fixed size (the T for Tag). Depending the type of message the contents of it (the V for Value) can very so you specify its length (the L for Length) before the contents. The Length field also has fixed size
Suppose you have one message used to send user data to the server. You can define a message like:
0x01 0x0018 0x11 0x0003 tom 0x12 0x000F tom#hotmail.com
Tag: 0x10 User data. Length: 0x0018 Value: sub tags
Tag 0x11: user name Length: 0x0003 Value = tom
Tag 0x12: email. Length: 0x000F. Value = tom#hotmail.com
Edited:
I was about to forget: Merry Christmas :)
Take a look at BEEP.
You might also find some good examples at four.livejournal.com; he's gotten good results writing an HTTP parser using the Ragel state machine generator, and also by hand.
if your not comfortable with the limitited functionality (verbs) provided HTTP just add more verbs. This is what the REST architecture is for.
If you want to continue down your path of folly (your talking about reinventing HTTPS), then use protocol buffers to create a protocol -- it will save you hours of grief.
-- edit --
If your objective is to understand the programming involved with web-servers, you might want to read apache's code dissected by the FMC group into a collection of models. I have read this PDF multiple times -- it is an absolute gold mine.
All the other comments are good, and stuff like BEEP, or doing some custom TLV encoding can get you along way, as well as using something like Google protocol buffers, but none of these are what I'd really call real simple.
A very simple text based protocol could just use a new line as the message delimiter. This is how IRC does it. Its not the most efficient, but if your messages are reasonably small it could work quite well. You could also prefix your message with a much shorter line telling the receiver how long the next message is.
If you want to use a light framework, look at libevent. It can assist in your IO and do line delimited reading for you.
If the language (protocol) is not already determined for you, then that is what you should design first, or look at something that already exists - XML, JSON chunks, netstrings, etc.
You can look at some of the sample code from TCP/IP Sockets in C.
It has many examples of doing client/server communication in C. Without more details, it's difficult to know what you really want to handle...
For communicating between bespoke apps, you can just send your text format in TCP packets. You can use an extremely simple text format, but you should make sure that it starts with some text that clearly identifies to your server that it is a packet from your client, and not from an imposter. (Clearly this is not terribly good security, but that's not the point of your question).
A good place to start is to use XML for your text-based format. This is dead simple to write/read, and is flexible and extensible so you can easily add more information to your packets at a later date - the biggest thing you can get wrong is to use a communications format that can't be extended!
Once you have basic comms working, you can enhance the format to send more information, add encryption and other security measures, and consider moving to a binary (more secure, more compact and efficient) format. BUt you can work your way to this stage in small easy steps.
So the right direction:
Get two programs talking via TCP. Just a simple packet with the text "bob" in it is enough at this stage, just to verify that the messaging is working. There are any number of simple tutorials on the web to get this going, and it's just a few lines of code once you work out what's needed.
Then build your packets. Start with the simplest approach that gives you a unique ID (to verify that the packet is from the right program) and a means to add new data to the packet easily in future. Xml is ideal for this. Don't worry about security, just concentrate on the actual "conversation" you wish to convey between the programs - what data they wish to exchange and how to encode it.
Step by step improve the communications protcol until it achieves what you want - smaller, faster, binary, more robust, fault tolerant, secure, etc. Each of these steps will be an interesting little challenge and by the time you've done them all you'll have learned a lot.
Look at the chapter on text protocols in 'The Art of UNIX Programming' by E S Raymond. It covers a lot of the relevant ideas at a high level, with good examples, and explanations of why they are good examples. It mentions BEEP.
I've recently read a book on this topic. It's called "TCP IP Sockets in C", by Michael J. Donahoo and Kenneth L. Calvert. You if you can afford it, it's a nice tutorial/reference book to have.
If you'd like you can try create the client<->server pair in Java, as it is easier to grasp the idea, and then rethink the solution at a lower level in C.