(update) I have got this working, exactly as described in the Igoe post – The code is in EthernetPachubeTweeter_tz1.
Essentially, anything that originates from the Arduino is sent to a feed in Pachube. That feed has a datastream which has a trigger which tweets any new data which arrives.
The next thing to try is figuring out whether this can be done as a single line http: request in curl, and therefore, from Max – or any other source
The potentiometer on the control radio changes the motor speed of the RC car. A potentiometer on the other side controls the brightness of an LED at the controller.
The xbee radios should be set up as directed – starting on p. 195
Here are the xbee settings:
ATMY
ATDL
ATDH
ATID
Radio 1
1234
5678
0
1111
Radio 2
5678
1234
0
1111
construction
2 stacks:
1) arduino + wireless SD shield + xbee
2) arduino + motor shield + wireless SD shield + xbee (motor shield hooked to RC car motor)
Each stack has a potentiometer, tx/rx leds, LED for remote brightness control, and batteries.
The motor shield has connections to the RC car motor and 9V battery for power.
code
Code for radio 1: xbee_full_duplex2_radio1.ino
The motor side uses a few lines of code from an instructables.com motor shield tutorial. LED brightness is linked to motor speed – sent out on pin 3 – from the Arduino sketch:
code for radio 2 (car): xbee_full_duplex2_radio2_motor.ino
note:
When loading the sketch, set the slide switch on the Wireless-SD shield to ‘USB’ – then switch it back to “micro” to run.
If the controller radio (radio 1) is connected to a computer, open the Arduino serial monitor – or the sketch will block – and nothing will happen.
Download
[wpdm_file id=20]
circuit layout
radio 1
pin A0 : input sensor (potentiometer)
pin 2 : tx LED
pin 3 : rx LED
pin 9: test LED (receives brightness data)
radio 2
pin A0 : input sensor (potentiometer)
pin 3: used internally for motor speed – (the motor is hooked to Channel A on the motor shield)
pin 4 : tx LED
pin 5 : rx LED
pin 10: test LED (receives brightness data)
Re-assign some of the pins from the xbee example so they aren’t on the same ones as the motor shield is using: Here’s the pin layout that the motor shield uses. i.e.. these are the pins that are used in an Arduino sketch to control each motor function. This project only controls ‘speed’ on channel A (pin 3).
Function
Channel A
Channel B
Direction
Digital 12
Digital 13
Speed (PWM)
Digital 3
Digital 11
Brake
Digital 9
Digital 8
Current Sensing
Analog 0
Analog 1
notes
This Arduino forum post was also helpful – otherwise I would have assumed that the shields were incompatible:
Tried this sketch and it actually works – local version is:
morse_code_AM_1337_xmtr
Instructions
tune AM radio to around 1337 KHz
Plug antenna (random length piece of wire) into digital pin 8
open serial port set to 9600
type in some text and press <return> (but not too much text at once)
Here is a link to a circuit using a crystal oscillator component and a serial port from windows computer to turn it on and off to make cw, also a suggestion (below) to expand it to use audio modulation…
To those wanting to send audio (as in music/voice): You will need an audio transformer. The transformer has 5 leads: 3 on left, 2 on right. The 3 lead side: connect the audio jacks ground on bottom, input on top leaving the middle lead free. The right side: batteries + supply on bottom lead, the top lead connects to the oscillators input pin. What you used as the ground should be the same. Just plug it into the computers “audio out” plug. To transmit music, play it with whatever music player you like. Plug it into a mp3 player/ipod/cd player and take it with you where ever you go. To send voice, plug mic into pc “audio/mic/line in” plug.
update 6/2014: Cosm is now Xively. Have not re-tested examples below. There is a working Twitter example at internet sensors projects: https://reactivemusic.net/?p=5859
original post
notes
Today I was finally able to get this working. Reading a Cosm (Pachube) feed from curl and from Max. Here is an example that works in curl: (replace API-KEY with actual key)
Update 5/2014 – all of these examples are broken due to Twitter API upgrade that requires OAUTH instead of user/password. Have left this post – as an example of what you can do. For examples of alternatives, see the internet-sensors projects: https://github.com/tkzic/internet-sensors
— original post —
Here is an example that I actually got working to track mention of dogs… You need to replace USER:PASS with your Twitter login and password. The JSON search results will be written to the file tweets.json.
A running tally of results will be displayed to the console while this is running.
Do you have a specific example which doesn’t appear to work? Following Taylor’s advice, I was able to find several streaming entries tracking the “photo” keyword:
