How to change Twitter trigger with Xively to use Zapier


This method was used to fix the tweetcurl series of Max patches and anything else which uses Tom Igoe’s method of sending tweets from Arduino via cosm. (old method)

The automatic twitter trigger used in the “internet sensors” project via cosm, stopped working when cosm migrated to But it works correctly from a device (or Max) to xively. So you don’t need to change anything except the xively trigger associated with the feed.

The fix is to go into your xively feed (legacy feed) delete the existing trigger and set up a new trigger using zapier – using the instructions in this tutorial.


  • You will need to sign up for a free zapier account
  • the text value of the tweet for zapier is called “body trigger datastream value value”
  • limited to 10 tweets per hour
  • when you select Twitter as an action in zapier, it will attempt to log you in to do the oauth authentication. If you are already logged into Twitter – make sure its the correct account.

If you really want to send Tweets from Max, check out the Twitter client that uses ruby:





how to open, read, and write from a serial port in C (linux)

With applications for Raspberry Pi



C – programming example:

An R-Pi thread about connecting Arduino to R-Pi. R-Pi does TTL (3.3 v level and Arduino is rs-232 5v) so you need a level converter for them to communicate.

Another similar example, connecting Arduino and R-pi via USB

The WiringPi library for serial io:






RTTY with Arduino

Transmitting on 434.650 MHz.

Successfully ran the configuration described in this article

By Anthony Stirk at UKHAS

Have only tried 50 baud – but the beacon ran for over an hour without errors. The receiving   setup was done on a Windows 7 computer:

  • Funcube (software defined radio)
  • FCHID (software to tune the Funcube)
  • Spectraview (demodulate signal from Funcube to SSB)
  • FLDigi (decode RTTY using custom setup)

The bandwidth of the RTTY signal was close to 900 instead of something more reasonable like 50. This can be adjusted by trying various resistor values in the voltage divider circuit.

Next steps include building antennas and increasing the baud rate.


using a WiFi router as a closed local network

I set up a WiFi router today at school, with no internet connection to use for ssh logins to Raspberry Pi and OSC experiments with Arduino. It has the same SSID as my home router so it will be interesting to see what happens when I go from one place to the other. 

Update: Actually this works great. Have been using it for any situation that requires OSC.

Arduino INPUT_PULLUP mode


When reading the value of a switch with Arduino, its useful to set the INPUT_PULLUP mode so you don’t need to use an external pullup resistor. By the way, the internal pull-up resistor is 20K ohms.

See this tutorial:

If its not clear what a pull-up resistor does,  read the links on this forum post.,22274.0.html

Everybody has their own way to explain it. I would say that when the switch is open, the pull-up resistor weakly pulls the logic value high, so you don’t get random signal readings.