Logic Analyzer is the essential tool for Embedded Development. – JimmyIoT
LA1010 USB Logic Analyzer 16 Input Channels 100MHz with The English PC Software Handheld Instrument,Support Windows (32bit/64bit),Mac OS,Linux: Amazon.com: Industrial & Scientific
USB Logic Analyzer - 24MHz/8-Channel - TOL-18627 - SparkFun Electronics
Low Cost DIY Logic Analyzer – Arduino++
Choosing a Logic Analyzer - Saleae Articles
Logic Analyzer for Protocol Analysis | Prodigy Technovations