error: Input 0 of layer sequential is incompatible with the layer expected min_ndim=3, found ndim=2. Full shape received: (None, 178)

error: Input 0 of layer sequential is incompatible with the layer expected min_ndim=3, found ndim=2. Full shape received: (None, 178)

# Xtrain.shape
# (14720, 178, 1)

epochs = 20 
model = Sequential() 
model.add(Conv1D(filters=32, kernel_size=2, activation='relu',strides=1,input_shape=Xtrain[0].shape)) 
model.add(BatchNormalization()) 
model.add(MaxPooling1D(pool_size=2, strides=2)) 
model.add(Dropout(0.1)) 
model.add(Conv1D(filters=64, kernel_size=2, activation='relu')) 
model.add(BatchNormalization()) 
model.add(MaxPooling1D(pool_size=2, strides=2)) 
model.add(Dropout(0.2)) 
model.add(Flatten()) 
model.add(Dropout(0.4)) 
model.add(Dense(256, activation='relu')) 
model.add(Dropout(0.5)) 
model.add(Dense(1, activation='sigmoid')) 
model.summary()

model.compile(optimizer=Adam(0.001), loss='binary_crossentropy', metrics=['acc'])

plot_model(model,to_file='model_plot.png',show_shapes=True,show_layer_names=True)

history1= model.fit(Xtrain, ytrain, validation_data = (Xval, yval),batch_size=200, epochs=epochs)

generates error 

Input 0 of layer sequential_2 is incompatible with the layer: : expected min_ndim=3, found ndim=2. Full shape received: (None, 178)