Design a wireless sensor network node.

I need to do wireless sensor network experiments, so I need wireless sensor network nodes similar to TelosB, MICA series, etc. Since I need to make many of these nodes to complete the experiment, I hope to compress the cost of each node. This node is mainly divided into four modules: processor module, communication module, power module, and sensor module. The sensor module collects data (such as light sensors, temperature and humidity sensors, etc.), which is processed by the processor module and then transmitted through the communication module (RF, Zigbee, etc.). The power module supplies power (battery or button battery). I hope this node can be as cheap and small as possible, and the functionality can be simplified as much as possible compared to TelosB, etc. It is best if someone with wireless sensor network knowledge can teach me how to make such nodes. Attached are some common node pictures.