AXE210

[frankilische]

Good day house,

I am new to using PICAXE and i have a very limited time to do what i need to have done, i have been trying to figure this out but a bit confused on how to go about it, i Actually am using the AXE210 boards in my wireless sensor network topology, where i have terminal nodes and one master node which could have had the MAX3232 chip and gone straight to a computer through the serial cable, but i want to get the computer out of the picture and send data to the internet. i was doing some background work trying to figure out relevant hardware and i came up with the RN-XV module from this link .......http://www.sequoia.co.uk/components/product.php?d=3&c=53&f=5&p=1483&fmt=grid.........it obviously would be taking the slot for the XBEE module and since i need the master node to be able to communicate with other terminal nodes to get data from them, i cant get out the XBEE unit from the master node, meaning i have to figure out a way to put all these together. I then thought up connecting two AXE210 boards with one having the XBEE module on it and the other having the RN-XV on it, where the board having the XBEE on it receives data from terminal nodes and pushes it to the other board having the RN-XV which then sends out to the internet. Obviously the connection between both boards has to be through wired means since they both wont be having XBEE modules on them, and thats where i have gotten stuck. I can figure out the programming part of it but need to be clear on how to connect these two boards to be able to communicate. Please any contribution from the house would be highly appreciated cos i am seriously running out of time to finish up on this.
Thanks in Anticipation.

 

[MartinM57]

I can't help you at all, but if you are seriously running out of time, you need to make it easy for people to understand what you are wanting:
- please use paragraphs rather than just a stream of consciousness
- describe the "big picture" very very simply - you are obviously doing something quite complex and using just words can be difficult (pictures maybe?)
- make the questions stand out
- make the questions very simple

Good luck

 

[frankilische]

Sorry about that, the long and short of it all is that i want to be able to send data to the internet and was able to find a wifi chip form this link ....http://www.sequoia.co.uk/components/product.php?d=3&c=53&f=5&p=1483&fmt=grid ... which takes the slot of the XBEE unit. How do i have 2 boards communicating with one of them having the XBEE chip and the other having this wifi chip?

 

[papaof2]

Are you trying to receive data via XBee on the one board and then send it to the internet via the wi-fi board or are you asking whether the wi-fi board and the XBee board can be made to talk to each other at the RF level?

For the first scenario, you would use the serial interfaces to connect the two boards together, but you'll need a chip to control the wi-fi module and at minimum, handle network login (if needed),tell the wi-fi chip where to connect (URL or IP address), and recognize when a connection can't be made.

The wi-fi board will talk to your local wireless network. Only a device with an IP address (think PC) can receive the data you put into the wi-fi module. Going the other way, you need a device that sends data to the wi-fi module's IP address (again probably a PC).

Data source --serial--> XBee --RF--> XBee --serial--> wi-fi module --RF--> wireless router --> local network

If you're asking whether the wi-fi and XBee boards can communicate directly at the RF level, the answer is no. One is speaking Russian and the other is speaking Arabic. They'll never get together.

John

 

[frankilische]

Are you trying to receive data via XBee on the one board and then send it to the internet via the wi-fi board or are you asking whether the wi-fi board and the XBee board can be made to talk to each other at the RF level?

For the first scenario, you would use the serial interfaces to connect the two boards together, but you'll need a chip to control the wi-fi module and at minimum, handle network login (if needed),tell the wi-fi chip where to connect (URL or IP address), and recognize when a connection can't be made.

The wi-fi board will talk to your local wireless network. Only a device with an IP address (think PC) can receive the data you put into the wi-fi module. Going the other way, you need a device that sends data to the wi-fi module's IP address (again probably a PC).

Data source --serial--> XBee --RF--> XBee --serial--> wi-fi module --RF--> wireless router --> local network

If you're asking whether the wi-fi and XBee boards can communicate directly at the RF level, the answer is no. One is speaking Russian and the other is speaking Arabic. They'll never get together.

John

Thanks for this John, this is really comprehensive......the first Scenario is actually what i am trying to achieve but i just need it one way in that i only want to send out to the internet and not receive from it. When you talk about a chip, do you mean an entirely different chip or either the PICAXE or MAX3232 chips??, i think the wifi module in that link can be configured using AT commands for the IP address and SSID. Also with the serial interfaces, i guess you mean the TX and RX right? IF yes, would the connection be RX on XBEE to TX on WIFI and vice versa or both RX's and TX's together. Thanks for the response again. Its highly appreciated.

 

[papaof2]

The PICAXE may be capable of sending all the needed control info to the wi-fi chip - which PICAXE is on the board?

The Xbee -> wi-fi serial interface is TX of one to RX of the other, but I would probably include a 330R resistor in each lead for protection of the chips (I'm not paranoid, just experienced ;-)

The only concern is whether you can parse the incoming data from the XBee fast enough. You probably want to accumulate some block of data (xx bytes) then send out the entire block. Does the PICAXE on the wi-fi board have enough scratchpad area to store a complete block of data?

Can the wi-fi chip report that the network is down? If the network is down, what do you do with the data coming from the XBee? Is it discarded or do you need a way to store that data and send it later when the network connection is available? If you need store-and-forward, how much data would you need to store and how much budget do you have for adding a storage method? If an 18M2 chip is used, would the I2C pins be available for use? If so, you could store the data in EEPROM (cheap, limited number of write cycles) or FRAM (not cheap, 1 trillion write cycles) and send it when the network is restored.

John