Xbee I/O to Relay Shield v2.1

userHead soccerjmp 2014-10-25 00:13:27 4695 Views5 Replies

Thanks for reading this! I have been working on this for a few months and would like any kind of guidance or advice.

I am trying to develop a simple control system that will turn on a humidifier when there is low %humidity detected in a room.  A Campbell CR1000 Data logger is collecting humidity data in the room continuously. I need some way for the serial coms on this data logger to send information to my Arduino within the humidifier. Developing the humidifier with relays has been easy, the wireless communication, not so much.

2- Xbee WRL-10421 - XBee Pro 63mW Wire Antenna - Series 2B  from Sparkfun

1 - Dfrobot relay shield and xbee socket ... uct_id=496

1 - Voltage regulator for the xbee

Conveniently, there is a 5V port on the data logger that allows me to just power the xbee. Just for fun, I have the data logger send an ASCII character every second to the TX and RX pots that I have my Xbee hooked up to.  I set both the coordinator and router to AT mode because I want it to act as a "wire" between the two. Even when I know there is data being sent from the data logger com port, I cannot see any lights on the xbee registering a receiving signal. Below is my configuration

Modem XB24-ZB
Function Set - AT Mode  Router
DH-Serial # High of Coord
DL-Serial # low of Coord
Baud rate set - 115200
Remainder left as default settings

Modem XB24-ZB
Function Set - AT Mode Coordinator
DH-Serial # High of Router
DL-Serial # low of Router
Baud rate set - 115200
Remainder left as default settings

When I hook 1 Xbee to my computer and the other to my Arduino, I am able to transmit data from arduino to computer through the relay shield. This is not true in the other direction. I cannot seem to send data from my computer to the arduino and receive it. My question is  Does the relay shield only allow for transmission of the data? Can data be received from external sources and processed? Thanks for reading !!!!

2014-10-31 11:02:53 Hello Bacherak,

OK, but I think the trouble should be very fast. What is your switch status?
If you turn the switch to "Prog" side, it only could transfer the data from Arduino side, and can't receive.
userHeadPic Grey.CC
2014-10-31 03:40:07 Hey all!!! thanks for the responses.

The DFrobot board that I have does not allow for data to be sent into the Xbee. It only allows for data transmission. When I removed the relay shield, hooked up 3.3v, grou,d and the Tx and Rx. I was able to get the information that I wanted. This could be from a bad connection as Grey states. At this point I am not going to torbleshoot it.

userHeadPic soccerjmp
2014-10-30 18:18:52 Hello Bacherak,

Do you have a multimeter? Could you measure the xbee voltage? P1 (Vcc) P10(GND)?
I am not sure whether it is a bad contact.

userHeadPic Grey.CC
2014-10-30 00:32:09 Were you able to resolve the issue ? I am having the same issue. When I place the xbee pro on the relay shield, I am not able to communicate from the computer or back to the computer.
Need help here.
The ASSOC light does not turn on.
I also tried connecting external power.. but no success.
Kindly help us. WE have invested a lot of time and money on this..
userHeadPic bacherak
2014-10-27 10:20:01 Welcome Joe,

Did you turn the Prog Switch to the "RUN" side?
And what is your power supply of the relay shield?  Does the "ASSOC" led light? I remember it requires an external power to run the xbee module.
userHeadPic Grey.CC