C1 + M1
C1 and M1 devices are interconnected by four interface lines:
C1 modules do not have dedicated ground and power lines. Sometimes, such lines are just not necessary.
However, some C1 devices, such as #18 (power input), need to be connected to the system ground. Tibbit #18 was designed to be used with power supply Tibbits #09 and #10, as well as the newer wide-input-range power Tibbit #33. These "M" devices provide ground on their pin 5, which solves the problem. Incoming supply voltage (Vin) is routed through pin 1:
Several C1 modules implement various sensors: temperature, humidity, pressure, etc. These need both the ground and +5V power lines, which are provided by the "M" Tibbit #00-3. This Tibbit propagates ground through pin 5 and outputs +5V power through pin 4:
