Forgot to put down these two links - 1. Source code at <a href="http://dev.laptop.org/git?p=projects/measure;a=summary">http://dev.laptop.org/git?p=projects/measure;a=summary</a> (You could git clone it like this: git clone git://dev.laptop.org/projects/measure) 2. Wiki Page - <a href="http://wiki.laptop.org/go/Measure">http://wiki.laptop.org/go/Measure</a>  (The peripherals would be put up on this page in a day or two) thanks, Arjun <div> On 9/15/07, Arjun Sarwal <<a href="mailto:arjun@laptop.org">arjun@laptop.org</a>> wrote:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Measure Activity on the XO (The Activity which converts the XO into an oscilloscope, a spectrum analyzer and a data logger !) Release 9 of the Measure Activity (build  575 onwards) features an improved UI and the following basic features - * Apply an AC or DC signal into Mic_In port, or simply observe the sound signal picked up from the Mic on the XO * Watch the signal in time domain for frequency domain representation * Toggle the bias voltage at the Mic_in port ON/OFF. This voltage is required by many sensors. * Log data at a specified interval, take a snapshot of the current waveform; and draw a graph of the logged data too. How can you help ? (1) Help in software development of the activity. There are many refinements and features that can further be added. I have put some of the priority ones down as tickets in Trac. Have a look at #3435, #3437, #3438 and #3461. (2) Do projects (and help document them ) around the Measure Activity. Ideas ranging from building a low cost ECG system to a low cost intrusion alarm system. I've built and tested two ideas illustrating the concept : =>'A low cost intrusion alarm system' that makes use of a toy laser that I powered from the USB and used a simple LDR (light dependent resistor) connected to the MIC_IN. Switch on the bias, set the activity to DC mode; observe the voltage change when the light path of laser upon the LDR is cut! =>'Temperature' monitoring system that I made simply with an LM35 temp sensor, and I powered the sensor from the USB port. (3) Help develop content and curriculum around the Measure activity. Science experiments, Physics concepts...being able to relate concepts with physical phenomena through hands on experiments makes for great learning ! For example, kids can whistle into the mic and using the frequency domain display mode in Measure, compare and learn about frequencies... (4) Want to build a low cost science/physics/chemistry lab ? A tele-health monitoring system ? Lots of possibilities to be explored. All new ideas welcome! (5) Help document such projects and other cool ideas . We would , in probability, be going in for Makezine DIY style documentation of such projects - with cool illustrations, photographs and explanation... Get in touch with me at <a href="mailto:arjun@laptop.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">arjun@laptop.org </a> for any details/clarifications. Looking forward to great collaboration and support from the community. sincerely, Arjun </blockquote></div>