MQTT Simulator for IoT Sensors

I'm in need of a simulator that can mimic communication from a set of IoT sensors via the MQTT protocol. This simulator should be able to generate and send various types of data that these sensors would typically produce.

Key Requirements:
- Simulate interaction of multiple sensors
- Support for the Wi-Fi communication protocol
- Generation of specific types of data: Shaft Revolutions, Electrical Readings, RFID Codes

Ideal Skills:
- Proficiency in MQTT and IoT concepts
- Experience with simulation software
- Understanding of Wi-Fi communication protocol

Please provide examples of similar projects you've completed in your proposal.