Yes, you can create Trading algorithms based on Technical analysis in Pi. Also, you can backtest it on past data. Once backtested, you may create a scanner based on your algorithm which can alert you once all the conditions of algorithm are met. These trading algorithms are known as Expert Advisors in Pi terminology. Below are some of the popular expert advisors:
http://tradingtuitions.com/most-popular-expert-advisors-for-zerodha-pi/
Also, you can create your trading strategy in Amibroker and link it to Pi through Amibridge. Below are some of the profitable Amibroker strategies:
http://tradingtuitions.com/category/categories/amibroker/trading-systems/