No communication using Parallax 5v-3.3v adapter, XBEE pro 802.15.4

Hello to U all,

I seem to have a communication problem using an Parallax 5v-3.3v adapter connected to an Arduino Duemilanove, using newsoftserial.
Spend a lot of time searching the forum, found no solution yet.

My project is as follows : 2 Xbee pro modules connected to 2 Arduino Fio boards. All they have to do is send a signal when a sensor is triggered. On the receiving end is an Arduino + parallax 5v-3.3v adapter + Xbee pro + newsoftserial.

During testing I used an Parallax Xbee USB adapter board, with the Xbee pro receiver connected to my computer. This works perfect.

However, when I connect the Parallax 5v-3.3v adapter AND the same Xbee pro reciever to the Arduino Duemilanove, I get nothing :frowning:

Power supply to the Xbee is OK, when one of the sensors is triggered the RSSI led on the Parallax 5v-3.3v board goes on, but I get no serial data received on the Arduino.

Dout of the parallax board goes to pin6 of the arduino.

I would really like to have an outside look to my problem :slight_smile:

Do I need some sort of level-shifting ? Is it me :slight_smile: Is the parallax board broken ?

Thanks for reading, any help is appreciated.

Greetings, Frans

Thanks for reading,

testxbee.pde (784 Bytes)

While you provided a lot of details, there is still a lot missing.

Links to the hardware would be a good starting point.

What kind of XBees are they - series 1 or series 2? How are they configured?

How is the XBee connected to the parallax board? How is the parallax board connected to the Arduino?

The Parallax board appears to have a number of LEDs. Do any of them ever light up?

Are there just the three wires between the Arduino and the Parallax board?

There is a note in the assembly instructions that I was looking for:

Caution: Voltage regulator supply current limitation.
The FAN2500S33X regulator used on Rev A of this adapter is rated at 100 mA continuous, 300 mA peak
current. VCC may be used as a 3.3 V supply output, but be sure that you budget enough current for
your XBee module as well as any other device you might supply through this regulator. The regular XBee
modules (Series 1 and Series 2) draw less than 55 mA, but XBee Pro modules can draw over 200 mA
when in a continuous-transmit state. While this adapter board can supply enough current for the
intermittent transmissions of XBee Pro modules typical to many common uses, applications requiring
continuous, sustained transmissions from XBee Pro modules would be better suited to the XBee SIP
Adapter (#32402), or the XBee Adapter Board (#32403) with an external regulator (not included).

Hello Paul,

No, there are 4 wires between the parallax board and the arduino. +5V, GND, RX and TX.

PWR led is lit.
ON_SLEEP led is lit.
ASSOC led blinks.

When one of the transmitters send a signal (because of the connected sensor that is triggered) the RSSI led on the board is lit for about 5 seconds, and the RX led flashes briefly. That is OK, because according to the schematic diagram of the RX led is connected to DOUT of the XBEE reciever.

It all looks like it's working, but it's not..haha...

Greetings, Frans


To follow up on my own post : it works :slight_smile:

Tried using a different powersupply to the parallax board, tried level-shifting, nada.

While Googling I found that the Arduino Mega 2560 has 4 serial hardware ports. Ordered one.

Soldered the parallax 5v-3.3v xbee adapter to serial port1, tada, got data from the xbee.

Just wanted to let U know.

Greetings, Frans