IO Nodules
		NOTE The QUUB will now use ArdweeNODEs so this information is redundant. While Quub IO stackables can be designed to implement IO in the same manner as all other embedded systems — ie. predetermined combinations of analogue/digital in/outputs — the IO Nodules (IONs) concept allows a generic IO board to have a custom configuration by just plugging in the combination of IO that is appropriate for the application. Also the ION system allows analogue readings to be taken right at the location of the quantity being measured, the value is converted to digital on the spot so there are no analogue-type issues such as noise and voltage drop. IONs are tiny, all currently designed nodules fit into a 25x25mm (1 x 1") potting box and have PCBs .9 x .9" in size. However test designs have been done with PCBs down to 12x12mm (.5 x .5") and you'll see that many of these designs have oodles of spare room on the PCB. IONs can be designed to perform any IO function, and many standard functions are currently at the design stage. Because IONs can be isolated (by adding a ISOMOD module) they can be used to measure high-side voltages and currents or even mains-level voltages. IONs have a tiny processor and a small amount of logic to implement the nodule's IO, the on-board processor communicates to the Quub stackable or the Quub core processor using the I2C protocol. NOTE: IONs now use I2C to communicate and have an 8-way header, the illustrations don't show this and are in the process of being updated.
		IONs currently designed
		At present a range of IONs to cover basic monitoring and control functions have been designed. VOLTS - An analogue input that can read up to 30v with 12-bit resolution. AMPS - This nodule uses a hall affect sensor to measure currents up to ±20A. The contacts are isolated even if not plugged into an isolated stackable. TEMP - Measures temperature in the range -55 to +150°C. TCOUPLE - Thermocouple interface, 0 to 1000°C. RELAY - A voltage-free contact pair for controlling lights, small pumps etc. Can switch voltages up to 100v AC or DC, and currents up to 1A with a 33-watt limit. The contacts are isolated even if not plugged into an isolated stackable. This nodule uses a latching relay, therefore the output state persists if the power is cut. SSRELAY - A solid-state relay, can be used directly for low-power loads or to control a larger SSR for high-power loads. DIGITAL IN - Two digital inputs that can withstand ±25v continuous and up to 15kv ESD. COUNT - A high-speed counter to measure period, frequency or events. ALARM - A piezo buzzer. ISOLMOD - A module that will galvanically isolate any ION.
		Other IONs to be designed
		There is no practical limit to the functionality of an ION, some functions I can think of are. SERVO - Drives a hobby servo. HUMIDITY - Reads relative humidity. VOLTS - Outputs an analogue voltage. KEYPAD - Interfaces to a 4x4 key pad. INFRARED - Receives IR data as emitted by remote controls. LED - A simple 4-digit LED 7-segment display. LCD - An 8x2 LCD display. GPS - Features a GPS module. ACCELEROMETER - A 3-axis accelerometer. GYRO - A gyroscope. LIGHT - measure the amount of light falling on an LDR. RANGE - An ultra-sonic range finder. PIR - Passive infrared sensor for detecting people. ROTARY ENCODER - Essentially a "knob" you can turn to enter a value into the system. HALL EFFECT - For detecting the presence of a magnet. 420MA - 4-20mA interface.