In order to enable environmental sensing in any place, wireless sensor networks that collects environmental sensing data through wireless multi hop communication are coming into practical use. Since sensor devices may be installed without a power supply, sensor devices should be powered by batteries. For this purpose, IEEE802.15.4 has been standardized and commercialized. However, services using these sensor devices are not widespread because the sensor devices are expensive relative to the value of the provided services and the power consumption is unexpectedly large. Therefore, in this study, we proposed a new communication protocol Duty-cycle Data-collection over Wi-Fi Direct (DDWD) for wireless sensor networks that works on cheap microchips such as ESP8266EX, which are equipped with Wi-Fi functions and are available for under 10 USD. In order to use ESP8266EX in multi hop wireless sensor networks, it is necessary to transmit the sensing data to the sink node efficiently while sleeping periodically to reduce power consumption. In addition, inexpensive hardware such as ESP8266EX has low accuracy in time counting, which causes a large error in the sleep time interval and time synchronization. Therefore, the protocol must be robust against time synchronization errors. The proposed protocol adopts Wi-Fi Direct, in which a node dynamically switches its operation mode between SoftAP and STA modes according to the time-divided slot, and exchanges messages with neighboring nodes through Wi-Fi Direct. The communication path is determined in an autonomous decentralized manner. All nodes operate only in the allocated slot to reduce power consumption. By limiting the operating slot interval to about several tens of seconds, low power consumption and reliable data collection are possible at a constant time interval, even if an inexpensive Wi-Fi chip with low accuracy in time counting is used. We implemented the proposed protocol in ESP8266EX and conducted an experiment to show the reliability and the low power consumption of the protocol.