Coding the Headlamp

Concepts:

• Sensors (Light)
• Pixels

Duration: 15 minutes

Step 1: Turn the lamp on when it’s dark

From INPUT, drag an on light block to your project. Set the condition to dark. Then, from LIGHT, drag a show ring block inside on light. To turn the lamp on, we will make all the pixels white, so use the color wheel to do that.

input.onLightConditionChanged(LightCondition.Dark, () => {
    light.showRing(
    `white white white white white white white white white white`
    )
})

Step 2: Turn the lamp off when it’s bright

This step is almost identical to Step 1. Drag the same two blocks again into your project, the on light with a show ring inside. This time, however, set the on light block’s condition to bright instead of dark. Color the pixels on the ring to gray instead of white.

input.onLightConditionChanged(LightCondition.Dark, () => {
    light.showRing(
    `white white white white white white white white white white`
    )
})
input.onLightConditionChanged(LightCondition.Bright, () => {
    light.showRing(
    `black black black black black black black black black black`
    )
})

Step 3: Adjust the light sensor

The default for the bright condition is set to detect very bright light. Also, the default for dark, is nearly total darkness. Let’s adjust this so that a room with normal lighting starts the on light block for bright. We’ll do the same for on light with dark.

From INPUT, go down to … MORE, drag two light set threshold blocks inside the on start block. Set one of the two threshold blocks to dark with value 65, and the other to bright with value 80.

input.onLightConditionChanged(LightCondition.Dark, () => {
    light.showRing(
    `white white white white white white white white white white`
    )
})
input.onLightConditionChanged(LightCondition.Bright, () => {
    light.showRing(
    `black black black black black black black black black black`
    )
})
input.setLightThreshold(LightCondition.Dark, 65)
input.setLightThreshold(LightCondition.Bright, 80)

Explore!

Download the code to your Adafruit Circuit Playground Express and explore dark rooms with your new headlamp!