Analog kit modules: Hall, light, knob, steam

Four three-pin analog modules read with analogRead: the KY-035 Hall sensor, the TEMT6000 light sensor, a rotation knob and a steam sensor.

Four three-pin analog boards from the starter kits, each read with analogRead: the KY-035 analog Hall sensor, the TEMT6000 ambient light sensor, the analog rotation sensor (Keyestudio Ks0014, DFRobot DFR0054) and the Keyestudio steam sensor (Ks0203). Aliases: analog magnetic sensor, ambient light module, rotary angle sensor, water vapor sensor.

Pins

Part	Pins	Output
ky035	S, VCC (+), GND (-)	S: half the supply with no field
temt6000	SIG, GND, VCC	SIG: rises with the light
rotation	S, VCC (+), GND (-)	S: 0 to the supply as it turns
steam	S, VCC (+), GND (-)	S: rises as the comb fogs

The sensors

KY-035. A bare 49E with nothing else on the board, the same model as the 49E: 1.4 mV a gauss on 5 V from half the supply, up for a south pole at the printed face and down for a north. Drag the magnet; click it to flip it.

TEMT6000. A phototransistor with its emitter on SIG and 10 k from SIG to ground. Vishay's sheet gives 50 uA at 100 lux (10 uA at 20), so SIG is 5 mV a lux on 10 k: 0.5 V at 100 lux, 2 V at 400, and it saturates a tenth of a volt under the supply past about 950 lux on 5 V. The widely copied "2 uA is a lux" is four times the sheet, and lux formulas built on it read four times too low; this follows the sheet. sensitivity is the microamps a lux, 0.5.

Analog rotation sensor. One linear pot with its track across + and - and its wiper on S. Neither wiki prints the value; 10 k is the common one and value is it. Drag the knob up or down.

Steam sensor. A patch of bare comb traces that a breath or steam fogs, joining the traces, so S rises with how much is wet. Keyestudio publishes no schematic and no figures, so this part uses the water level sensor's circuit and curve over a 0 to 100% control, with full (0.66) as the top. That curve is an assumption about this board, not a measurement of it.

What it does not model

The 49E's drift and spread; the TEMT6000's spread (a factor of two either way), its 1.18% a kelvin, and the infrared it also sees a little of; the steam sensor's real curve, which nobody publishes, and the film of water that keeps a real one reading after the steam has gone.

Common mistakes

Wiring the rotation sensor's S to a digital pin. It is an analog voltage: use an analog input.

Expecting the steam sensor to measure humidity. It sees water condensed on the board, not the humidity of the air.

See it in action

Analog modules on A0 to A3 reads all four. Open it at /templates.