xbee communication in broadcast mode.

Wireless & IoT
1

I met problem in two xbees communication.

The system does consist of two xbee802.15.4, ADC and one pic16f628a.

The pic acquired some data from ADC, then send them to TX XBEE. RX XBEE will receive them, I can see these data on the X-CTU. it did work in breadboard testing. so I solered all the chips on pcb board. However problem happened.

  1. I can see data out of pic16f628a when I turn on power supply for the pcb board, but I doesn’t see data in X-CTU of RX XBEE.

  2. I also used MPLAB ICD programmer to control PIC16F628A, release, and hold are used. when I “release”, there are data on pic uart port pins, but I didn’t see anydata in RX XBEE’s X-CTU.

some special:

(1) I chose xbee broadcast mode.

(2) before transmit ADC data, I send some flag characters from PIC.

(3) I see pic uart pin data by capture function of oscillscope,

(4) the only difference is the TX XBEE DIN pin is a little shorter than others, but it is enough for soldered in pcb board.

(5)Sometimes RX XBEE receives the flag characters but no ADC data when I turn on power supply for pcb board.Often the flag character can be received as soon as power is tunred on.

Why? Do you have any idea about it? I need solve the porblem.

2

I would like to try to help you, unfortunately I cannot figure out what you are asking.

I’m not trying to offend you, as I assume that English is not your native language; but perhaps, you could post in a lot less threads and focus on making a few that are clear, concise, and easily understandable.

People here are more than willing to help, if we know what you are asking.

3

Thanks. I appreciate your help. :slight_smile:

4

Thanks for editing your post, and providing details!!!

Is the PIC running at 3.3 V? Is the Xbee Running at 3.3V (as it need to be)?

The XBee is a 3.3V device, and as such will expect 3.3V on it’s Vcc Line, and also any data flowing to/from the XBee must be a 3.3V signal.

Everything may already be at 3.3V, but I thought I would ask since it’s not mentioned.

5

You are welcome. and I like your true words, and your care.

Ok. PIC is 5V, so inverter is used twice before the pic output is sent to xbee.

6

I can tell from your other posts that you’ve worked with XBee’s in the past, so I realize that you’ve already tried all the simple stuff. (Hopefully I didn’t insult you above.)

The only thing I could think of would be to put a scope on the circuit, and watch the data as it leave the IO pin, and after the inverter where it connects to the XBee. perhaps the inverter is not functioning as it should?

Otherwise, since I’m not well versed in PIC stuff, I don’t think I can’t offer much else on this one.