I´m having some troubles using GPIO on Fastrack Xtend (FXT0009), and the real trouble is that I don´t have an idea how it works!!!
Reading some documentation I found that I have to connect the Vref line to 13V , and GPIO lines to ground (Im using 10k pull down buttons between GPIO and ground).
Im reading de signals with the following AT commands:
AT+WIOM=1,”GPIO21”,0 this command activates GPIO21 as an input.
AT+WIOR=”GPIO21” this command reads the GPIO21 level and
returns the value “1” which represents a HIGH level.
But when I press (and hold) the button i can´t get a change of the signal.
Is my form of wiring the trouble ?
Can anyone post a circuit that can be useful for this case? , at commands or some else that can help me.
hi, i also just received my FXT009 and i need to read digital input signals (to be more specific i need to decect if the two output pins of a relais are connected or not). after reading the “AirLink FXT Series User Guide” i’m not sure if i have to use resistors in the wiring. for a quick test, can i just use the shipped 6-wire cable and connect Vref to DC IN (12V) and then connect one of the GPIO pins with either Vref or GND? i don’t want to damage the FXT009 by doing something wrong. is there some wiring guide? or can you provide a link to the “Product and Technical Specification guide for FXT009” that you mentioned? i didn’t find a document with that name so far.
ok, i found this article which nicely explains pull-up and pull-down resistors: bit-101.com/blog/?p=3813
after reading this it seemed safe to connect a GPIO pin to ground and i tried it and it worked fine. i didn’t connect Vref to DC IN btw. i’m still not sure about this part but it seems it’s not neccessary for my project.