raspberry pi to poll measured data from many arduino sensors with nrf24l01 devices

to do this project, you need to have (1) one Raspberry Pi (Master) device, and one nrf24l01+ device is on Raspberry Pi. (2) many Arduino devices (slaves), and each Arduino device has one nrf24L01+ device. Master will send a "syn" signal to all slaves, every 1 or 2 seconds, to ask all slaves to do a measurement. All slaves shall receive a "syn" signal from Master every 1 to 2 seconds. Each slave, exactly after the receiving of the syn signal from Master, will start a measurement and store the measured data. To simplify, we may assume the measured data are, for example, 1111 for slave 1, 2222 for slave 2, 3333 for slave 3, and so on. All slaves shall send the measured data back to Master quickly, because Master will keep sending syn signal to all slaves every 1 to 2 seconds, to ask them to do the new measurements. If all slaves send the measured data back Master at the same time, the collisions will occur and some data may be lost. In this regard, i would like Master, after it sends out the syn signal data to all slaves, to poll the measured data back from slaves, one by one, one after one, to avoid the collisions and interference, and to collect all measured data from slaves, without missing and without collisions. The goal is for Master to keep updating the measured data from slaves every 1 to 2 seconds. to do this project, you must know Raspberry pi, python, arduino, arduino IDE software very well, and you must know how to use the firmware and library of nrf24l01+ very well. thanks for viewing this project.