This is a Tibbit module — part of the Tibbo Project System that allows you to build your own custom embedded device with only the components you need. Start with a Tibbo Project PCB, add Tibbits like this one, then place the built design into a Tibbo Project Box to complete your product.
Tibbit #04_4: Four opto-couple inputs with the '-' terminal connected to the system ground, independent '+' terminals.
The picture to the right shows a different Tibbit, but the size, color and shape are the same.
If no external resistor is added, these inputs activate at about 2V. Forward current should not exceed 10mA; this caps the maximum input voltage at around 5V. Add external resistors if you need to apply higher input voltage.
Note that these are not "isolated inputs"; they share the ground line with the rest of your system. Still, the optical stage isolates your system from noise, ESD, spikes, and other external influences.
Combine this Tibbit with a terminal block C Tibbit #20 (nine terminal blocks) or #21 (four terminal blocks).
There are four green LEDs each of which is connected to a control line. They light up for the LOW state (i.e. when current passes through the diodes of the opto-couplers).
M1S Tibbit Modules Overview M1S Tibbits are single-width modules occupying one standard M socket on a Tibbo Project PCB (i.e. TPP2 or TPP3). Their footprint is roughly 7 × 14 "squares" (one "square" is 2.54 × 2.54 mm). The M1S modules are 12.5mm high.
M1 modules have two rows of 6 pins:
Pins 8-11 are control lines A-D. They provide the interface to programmable modules or other microcontrollers. On Tibbo Project PCBs, these pins are connected to the main processor.
Pins 2-5 are I/O lines facing the outside world. On Tibbo Project PCBs, they go to C Tibbits.
Pins 6 and 12 are the GROUND and +5V power pins. Most Tibbit Modules consume (take) 5V power. There are also power supply Tibbits that generate 5V power from a variety of sources. Those output 5V through pin 12.
Pins 1 and 7 are for the additional +15V and -15V voltages. These are optional and only needed by few Tibbits. A special power supply Tibbit (#12) generates ±15V from the main 5V power.