Abstract: A downhole control device is configured to activate downhole equipment requiring control signals. The device having a housing adapted to protect electronic components; a transducer configured to measure one or more of pressure and temperature; an accelerometer; and control circuitry in communication with the transducer and the accelerometer and configured to control the operation of a downhole tool depending on data from one or more of the transducer and accelerometer. The transducer, the accelerometer and at least part of the control circuitry are mounted on a chassis that is removably inserted within the housing.