Relay driver shield for 24 relays (or more)?

Hi,

for my current project (a remote antenna and bandpass filter switch) I need to drive at least 24 relays.

In my third prototype I use 2 4x4 driver shields.

But isn't there a cheaper way? Or should I go the resistor-transistor-diode route?

Relays are 12v (13.8v) and are at some 5m away from the Arduino which is continuously connected to my pc.

Any suggestions are welcome!

check - RELAY8 8-Channel Relay Driver Shield Quickstart Guide | Freetronics -

by using multiple shield you can drive up to 8x8 = 64 relays AFAIU

Thanks for the info Rob, but that would make it even more expensive than the 4x4 solution.

I'll probably have to develop my own board/shield :cold_sweat:

i want to know about how many or mximum relay we can drive with arduino uno.