Wireless Sensor Networks impose a requirement of low power usage, implying minimal processing power on PHY/MAC layer transmissions. However the underlying channel between nodes can sometimes be hostile and incur interference from heavy traffic. In this situation a customized, simple, robust and adaptive forward error correction scheme is essential. This paper proposes an adaptive transmission power control and coding (ATPCC) algorithm for wireless sensor networks. The objectives of ATPCC are to enable every node in a sensor network and find the minimum transmission power levels that can provide good link qualities for its neighbouring nodes and efficient use of transmitting power. The algorithm uses rate compatible partial unit memory (RCPUM) codes, which have properties of both block and convolutional codes but require low encoding and decoding complexity. These RCPUM codes are bandwidth efficient in the sense that higher code rates are embedded within lower code rates and only parts of the codeword need to be transmitted depending on link conditions.