I have several raspberry pis, each one connected to a sensor module. I have written a C program which runs on each raspberry pi to communicate with the sensor module and to configure it properly (the driver for the sensor module is written in C).
The next step is to make the configuration of the sensor modules more flexible and to enable other applications to communicate with the sensor modules over the network.
To make the configuration more flexible I thought about creating a web application which is able to connect to the raspberry pis (all of them are in the same wifi) and configure the sensor modules remotely.
My idea is to create a REST Api which runs on each raspberry pi and enables the communication with the sensor module. But as my application is written in C, I was wondering if there is any better solution to my problem? I know that creating a REST Api in C is possible, but, as far as I know, it is not very common.
Would you think that creating a REST Api in C for this use case is a good idea and if so, is there any good framework available?
Also, if someone has a better idea for a different architecture, I would really appreciate it.
Thanks in advance!
Related
Non-programmable Xbee modules should be configured through a PC (with XCTU) or other devices like Arduino... but can the programmable xbee modules (like xbee-pro zb s2b) autoconfigure themselves, without being connected to another device like a PC or Arduino, by running code stored in their memory?
I mean, can they run orders like the ones you run through XCTU but programming them in the internal memory code? Like scan energy of every channel, select a channel, set a PAN ID, configure the different parameters of the device...
Thank you
Yes, the development kit includes an API for sending AT commands from the co-processor to the radio on those boards.
There's also a passthrough mode that relays the host computer serial port through to the radio processor, which can help with initial setup/configuration of the modules like you might do during manufacturing.
To answer your question:
I mean, can they run orders like the ones you run through XCTU but programming them in the internal memory code?
No. You can not program a sequence of orders/commands into the internal memory of the device. To do anything meaningful the device needs to be "driven" from a host PC or MCU that can send the AT Commands.
If you want 1 device solution that does not require a Host MCU then you will need to use a ZigBee SoC (System on Chip), such as the CC2538 - http://www.ti.com/product/cc2538 running a ZgBee SDK (Software Development Kit) - http://www.ti.com/tool/z-stack (ZStack-Home). However this will require you to develop the ZigBee application SW.
Regards,
TC.
I don't know if this is the right place to ask this. Sorry if I'm wrong.
I'd like to know if you can run code in an Xbee module without being connected to the computer or another device like arduino.
For example, I want to have 2-3 Xbee modules that communicate with each other sending information and then take decisions by code dynamically without using the X-CTU software. And I don't want those Xbee modules to be connected to the PC or other devices, they have to run by themselves with a coin cell battery and run some code previously written into their memory. Is this possible? If so, can you provide me some info/documentation to take a look? which language do you have to use to program the code? Which Xbee model do I need?
Thank you!
The XBEE modules can not do such tasks without a host. You can not run your own code on the module.
If you want to run you own code on the same device as the ZigBee stack then you should choose a solution from a silicon/stack provider.
You could achieve your goal using the Texas Instruments ZigBee Home automation SDK from www.ti.com/tool/z-stack which runs the ZigBee stack and your application on one of the TI ZigBee SoC's. But there are likely other similar providers as well.
Regards, TC.
XBees can be configured to initialize themselves with network data, i.e. the PAN ID, so they're aware of how to communicate on start up without requiring external configuration. However, they cannot run headlessly; they must to have some idea of the data that needs to be sent. They're fundamentally designed to act as a transparent serial bridge between computers to aid communications on personal networks. They cannot however be configured to do something bespoke.
It sounds like you're worried about power, so you could try looking for a low-power microcontroller that possesses a USART; this is all you'll need in order to communicate with an XBee via Serial.
It isn't possible to put your own code on a standard XBee module, but Digi does offer a Programmable XBee that includes a Freescale HCS08 co-processor that you can write code for. They offer a development kit with sample programs to get your started.
For a small-scale project where you don't need to be ZigBee certified, that might be easier than getting up to speed with a ZigBee development kit from TI, Freescale or Silicon Labs.
I want to establish Bluetooth network where one server can communicate to two clients (ie piconet) using C programm on linux platform, rfcomm based communication.
Can any one please share your guidance or sample source code if have.
I newbie to the bluetooth technology, have not found any useful info or code from internet source so far. so please.
Thank you
Basu
Linux runs open source BlueZ Bluetooth Stack, which works quite well (unless you need Bluetooth Low Energy). You can check out this tutorial: http://people.csail.mit.edu/albert/bluez-intro/c404.html
PS. Mind the GPL license when using #include like in those examples.
Edit:
As for creating piconet specifically, I'm afraid I don't have any snippets. However, after quick search, I would look into using bluez library to open not one but many RFCOMM sockets. So you can listen to and accept multiple connections.
So basically, me and a friend are using the Dragon12-Plus2 board for our class in school, and we are trying to get them to talk via Xbee chips. We have hooked one of them up, and simply need a bit of code to get the Xbee to talk with the board so we can make sure it's in correctly. We are writing in C using Freescale Codewarrior, and as much help as possible is appreciated, especially next steps such as when we hook up the other one, how to get the two to talk and test, etc. They should in theory already be set up as a point-to-point system, but we don't have much experience at this time. Any help would be greatly appreciated
If you configure the XBee modules with "AT mode" firmware, you should be able to use the serial port on the Dragon12-Plus2 board to communicate just as you would with a wired connection.
You'll need to configure both radios with the same PAN ID. Make one a coordinator and the other a router. On the coordinator, configure the DH and DL settings to match the SH and SL settings of the router. You can keep the router's default configuration of using 0 for DH and DL, which tells it to send data to the coordinator.
Do your testing on a PC with a two terminal emulators so you can verify that data sent in on one comes out on the other and vice versa.
Here's an excellent guide from the Digi website on Basic XBee ZB ZigBee (Series 2) Chat which provides more detail and a step-by-step guide for configuring the radios.
I have a dsPIC33 with ECAN and wish to establish a protocol (using SDO if possible) in such way that it communicate between terminal software and dsPIC33 where I can perform diagnostics within dsPIC33 and supporting ICs.
I do not know what is required, so what is a low cost way of doing this? I could use a CAN-to-USB device, but I am unsure if this will work. What kind of protocol inside CANUSB wraps around the ASCII-based message?
What hardware can I use? Can it be used to monitor the CAN bus as well? I do not wish to invest in an expensive setup as in Vector or similar heavy-weight solution.
When you purchase CAN interface hardware, it does not typically include software to work with specific upper-level CAN protocols (like CANopen). They do usually come with a set of DLL files that allow you to write custom PC applications to interface with your hardware.
If you do not want to purchase any third-party software, then you must:
Implement a basic CAN driver for the dsPIC33 (transmit and receive a basic frame).
Implement the CANopen SDO protocol on top of your basic driver on the dsPIC33.
Purchase a low-cost CAN<->USB interface (which should come with DLLs that allow you to develop in C, C++ or C#.
Write a PC application using the DLL files which implements the CANopen SDO protocol.
You may want to look for open-source implementations of the protocol. One such implementation is CanFestival. However, I have never used this library.
You can download an open source project for CANopen from DATALINK ENGINEERING as this seems to be just what you need.