I just received my SparkFun XBee Explorer USB. WRL-11812.
According to the artwork, pin 1 of the Xbee is 3.3v, pin 2 is DOUT and pin 3 is DIN.
My problem is that while I verified with XCTU that pin 2 is DOUT and pin 3 is DIN, pin 3 is held at 3.3v. I have verified with a scope that I am outputting on TX from my Adafruit M4 feather, when I connect DIN thru a 1k resistor , the entire TX signal is dropped across the resistor, indicating that my input resistance is <<<1k.
Also, I connected DIN to 0v0 (and) thru a 1k resistor and DIN remained at 3.3v.
Additionally, I used XCTU to change “DIN” to “output low”. This resulted in a reset. I thought that I had damaged the chip, but it came back to life after removing power to it.
I am assuming that DIN is a INPUT and DOUT is an OUTPUT, is this correct?
When I apply 3.3v at pin 1 and 0v to pin 10 and pull DIN low with a 1k resistor to 0v, DIN goes low with no problems. It is only when I use the USB adapter that I have the problem. DOUT maintains 3.3v when loaded with the 1k resistor to ground.
Please help to clarify this for me.
DIN and DOUT are used for TTL serial communication and may idle high.
DIN is Data In or serial RX and DOUT is Data Out or serial TX.
Additionally, if you have your XBee on a shield or adapter, it most likely has some sort of logic level converter that can also cause the pins to idle high.
I don’t recall if you can change the function of DIN/DOUT in XCTU to be GPIO rather than serial, it’s probably better to leave them alone so that you don’t unintentionally turn serial off and lock yourself out of being able to make any further changes to the XBee. (XCTU configures the XBee by communicating via DIN/DOUT, if you turn serial off, XCTU can’t access the XBee anymore.)
The input is at a ‘hard’ 3.3v. The input I provided was 3.3v. I tried to pull it low thru a 1k resistor. The entire 3.3v was dropped across the resistor telling me the input resistance was <<<<1k.
Is XCTU able to communicate with your XBee through the adapter?
Also, what adapter are you using?
Yes, I am using XCTU and can ‘talk’ to my Xbee. I am using spark fun’s adapter.
SparkFun XBee Explorer USB. WRL-11812.
Also, I connected DIN to 0v0 (and) thru a 1k resistor and DIN remained at 3.3v.
Additionally, I used XCTU to change “DIN” to “output low”. This resulted in a reset. I thought that I had damaged the chip, but it came back to life after removing power to it.
If XCTU is able to talk to the XBee, both DIN and DOUT are working correctly, it’s the XBee Explorer USB that’s pulling DIN high not the XBee.
If DIN was stuck high by the XBee, XCTU wouldn’t be able to see the XBee let alone talk to it. Everything seems perfectly normal to me, your XBee is fine.
Yes, this is what I am trying to say. I have a bad adapter.
Adafruit is sending me a RMA.
Just got it.
I cannot use the USB adapter, I need to use a Shield.
The USB adapter “takes over” and dedicates DIN to the USB input.
Thank You
No prob, glad you got things figured out!