[PIC] two device communication

[idontno]

Dear Helper,

I am working on my personal project in which I need to do communication between two devices, for instance a PIC - PIC or let say PIC - multi slaves (Master - slaves, bidirectional communication), where I am trying to do bidirectional communication, also I am working on how could I send request from master in order to retrieve specific data/record previously stored from target slave.

now my question is - will it be possible to do with I2C or RS485; or may be something else? because I want to go for wireless on later stage expecting same function

I am trying to explain in limited words but if anyone could get this then please let me know.

looking forward to any feedback.

thanking you in advance.

 

[betwixt]

It depends on several factors: the data rate, number of pins available and the distance being most important. I2C is good for fairly high speeds but only over short distances, RS485 is good for high speeds over long distances but can't be used for wireless links. Have you thought about using plain old serial and embedding an address field in the stream to address one receiving device out of many?

Brian.

 

[horace1]

if you are thinking of wireless the Microchip RN171 is a simple device to use
https://www.microchip.com/wwwproducts/Devices.aspx?product=RN171

it has an onchip TCP/IP stack and UART and SPI interfaces

also Lantronix has a range of devices
https://www.lantronix.com/device-networking/wireless.html

 

[idontno]

Hi,

Thanks for your quick reply, well I am using I2C at the moment and as you mentioned of course it will not cover long distance so why I will go for else, Data rate is going to be like in Kbps. however could you please help me to understand more about serial embedding? or please provide me any links which I can refer ?

I really concern at this stage is I have many slaves which I wanted to be wireless infect whole concept I wanted to be wireless so I also need to think something cost effective. I keep doing my research but mean while if you could please help me then It will be really appreciated.

Thanking you

Himanshu

- - - Updated - - -

Hi,

Thanks for your input it really helps me to understand more and I am thinking towards it. although I need to understand that how I could make this module it self work as a master and slave, I mean I thought first I need to establishes communication like i2c, RS series etc and then I can use wireless module in order to make it wireless but after reading your reply I put me self in thinking....unless if you could please let me understand then it will be really appreciated.


Thanking you

Himanshu.

 

[horace1]

I used the RN171
https://www.microchip.com/wwwproducts/Devices.aspx?product=RN171
in an infrastructure network with a central router and a PC running a TCP server - the microcontroller with the RN171 ran a TCP client program

it should be possible
1. to run a server (acting as a master) on PIC with the other devices as clients
2. to run an ad-hoc network without a router

microchip have a range of wireless devices
**broken link removed**

I used the RN171 as it can run an FTP client to talk to a remote FTP sever

 

[horace1]

if you don't require TCP/IP connectivity an alternative is to use Zigbee which typically has a coordinator (can be your master) and end devices, e.g.
**broken link removed**

Microchip's also have MiWi which is their own a simpler version of Zigbee (and I assume cheaper)

I have had transmission over several hundred meters with Zigbee coordinator to end device, I think using XBee modules
https://www.digi.com/products/wirel...es/zigbee-mesh-module/xbee-zb-module#overview

Nordic also have a range of low cost low power RF modules
**broken link removed**