Certified GKH Gardening Expert
Planting nightshade plants (peppers, tomatoes, potatoes, etc) near raspberry won't directly hurt raspberries, but the plants are vulnerable to the same diseases. If the nightshade plants develop one of these diseases, it can spread to your raspberries if they are in the same bed. Since raspberries are perennials and nightshades are annuals, just keep them separated so you don't kill your long lived raspberries by accident. Other than that, everything else can be planted with raspberries.