XBee radios can now record and output multiple channels of digital and analog data without using microcontrollers. The latest firmware (version 10A1) supports up to seven channels of analog input, nine channels of digital I/O and two channels of analog (pulse-width modulation) output. These will be great for creating small sensor modules or miniature output modules with low power and very low complexity.
Andrew Schneider and I cobbled a couple experimental modules together last weekend, and I recreated them for a demonstration to my Project Development Studio class. Here’s the presentation on XBee Direct that I gave to the class. Firmware updates can be performed with MaxStream’s X-CTU software, and you’ll certainly need to do this if your XBee’s were purchased before 2007.
Direct I/O should be considered for wearables, remote controls, toys, covert sensors, computational jewelry or anything airborne. Photos of the input and output circuits are below, along with the AT commands for this setup, with one analog (potentiometer) and one digital (switch) input, and the corresponding outputs (motor & LED):
INPUT MODULE:
ATID3456 –> PAN ID
ATMY1 –> my address 1
ATDL2 –> destination address 2
ATD02 –> input 0 in analog mode
ATD13 –> input 1 in digital in mode
ATIR14 –> sample rate 20 milliseconds (hex 14)
ATIT5 –> samples before transmit 5
ATWR –> write settings to firmware
OUTPUT MODULE:
ATID3456 –> PAN ID
ATMY2 –> my address 2
ATDL1 –> destination address 1
ATP02 –> PWM 0 in PWM mode
ATD15 –> output 1 in digital out high mode
ATIU1 –> I/O output enabled
ATIA1 –> I/O input from address 1
ATWR –> write settings to firmware
Input Module with Potentiometer and Switch
Output Module with Vibrator Motor and LED
Hi, I just read this post and was fascinated by it. I would love to know more. is it possible for you to direct me to any information about xbee direct, as i’m interested in developing a wearable sensor system. any information would be much apreciated. cheers. adam
Check the XBee User manual section 2.2.
I was curious as to what you did with this project. I might be interested in this as I am interested in developing a link between to devices - One that receives audio input and transmits it to the other. The other device will receive the audio and activate a pager motor. Would you think you’d be able to help?
Regards,
Shubs
Hi,
I want to transmit adc data in multihop manner to base node. Can i do it in XBee?
Regards,
Shailendra
To do multihop, you’ll want the XBee ZNet modules.
Hi, dear faludi~
“Xbee Series2(ZNET)” how to setup AT commands and use Direct I/O with ADC ?
Regards,
jupn.
Hello..
Sounds silly but how is the switch and LED connected ?
Switch is D1 to ground or +3.3 ?
LED is D1 Anode to ground or +3.3 ?
Maybe a schematic of the input and output circuits
Thank you
Switch in this case was connected to +V and LED to GND. However it’s certainly possible to do it the other way around, and maybe preferable since you could take advantage of the internal pull-up resistors in the XBee for the switch.