DIY engineers now go one step further. MAKE magazine reports that a Russian engineer has implemented a DIY capacitive touch pad. The system is built by referencing the whitepaper of Quantum Research Group (now acquired by Atmel). For unknown reason, I can’t open the linked PDF file.. So, I put another link for the paper here. All Quantum’s touch sensing ICs use Quantum’s propriety charge transfer sensing technique. You can easily understand its operating principles by consulting charge transfer sensing whitepaper.