State-of-the-art Network coding based routing protocols exploit the link quality information to compute the transmission rate in the intermediate nodes. However, the link quality discovery protocols are usually inaccurate, and introduce overhead in wireless mesh networks. In this paper, we present an adaptive approach for opportunistic routing which, adapts the threshold for activating the helper node based on the previous transmitted packets status in the next hop. Our simulation results show that this adaptive approach performs as well as the same approach with prior and perfect knowledge of the channel states. Furthermore, measurements using our Raspberry Pi testbed demonstrate that our adaptive approach outperforms the previous mechanism in real channel conditions, with only 1% overhead due to linearly dependent coded packets compared to the 11% overhead of the standard PlayNCool approach.