Hi,
does anybody have the pinout of the NCD XBee module? I notice that not all the pins of the Digi XBee SX SMT board are connected to the through-hole pins of the support that NCD built,
Does anybody have a list with the function of each through-hole pin, and how it maps to the mounted Digi XBee SX chip?
Thanks for the help.
Hi,
The only lines our boards utilize on the XBee Footprint Pinout are 3.3VDC, GND, Rx, and Tx.
Thank you for the explanation.
But when you say you utilize, you mean from a software standpoint, correct? Because I have noticed that some other lines of the XBee are connected to some other lines of the Atmel. e.g., line 10 of the XBee (DIO8/DTR /SLEEP_RQ) is connected to Line 1 of the Atmel ((PCINT19/OC2B/INT1).
So, the hardware is there if, say, you would like the Atmel to be interrupted every time the XBee board wakes up, am I right?
The reason I am asking is because I would like to consider setting the XBee Sleep Mode to 8 (Synchronous sleep). This way, all the nodes would wake up simultaneously at certain times (say, once an hour), Upon waking up, they could interrupt the Atmel to obtain a reading from the sensor, transmit the reading, and after all nodes communicated, they could all go to sleep.
The reason I would go to all this trouble is that I would like all nodes to be a part of the mesh network (relaying the readings of nodes that do not have direct connection to the gateway), but I cannot afford to have all the nodes always awake. With Sleep Mode 8, everything would work fine, but I would have to be sure that the Atmel would know when it is the proper time to perform a reading.
Does this make sense?
The products were not designed for the sleep mode sensors to work as repeaters. For this a very robust RTC system would need to be implemented which currently is not possible.
If repeaters are needed we recommend powering up these USB modems throughout the facility where constant power is available. If powered up via 12VDC these devices will act as repeaters for the Mesh Network:
Thank you for the suggestion.
Unfortunately, the environment where we will be deploying the nodes does not have access to power, as this is a water network. So, any powered nodes are out of the question.
The reason why we chose NCD products was because the nodes were advertised as being part of a mesh network using XBee DigiMesh. There was no disclaimer saying that only powered nodes can relay messages.
Now, we have a customer to whom we promised a mesh network of nodes, based upon your literature, and we absolutely need to deliver.
So, I went and studied the XBee board and the DigiMesh network. I concluded that it is possible to program the sleeping mode of the XBee to mode 8 (synchronous sleeping). According to Digi International’s claims, the XBee nodes can be programmed to wake up at the same time, act as a collective mesh network, and go back to sleep. That is what we are trying to do now.
My only question, now, is how will I tell the Atmel microcontroller that the XBee is awake, and it is time for the Atmel to collect a sensor reading, and send it to the mesh.
Since when the XBee wakes up, its line 26 goes to zero, I was wondering if it would be possible for that line to wake up the Atmel, signaling to it that another reading is expected. The Atmel would wake up, make a reading from the I2C interface, send it to the XBee, and go back to sleep.
This way, we would have the benefits of a true DigiMesh mesh network, without the need for a huge number of powered nodes in the middle. The nodes would be asleep most of the time, and they would all wake up synchronosly to communicate. This is the functionality I was led to believe the NCD sensor nodes would have.