If you have everything set up right, your new sun tracker should slowly start uploading data to Adafruit IO under the feed name 'ambient-light'.

Log into https://io.adafruit.com/ and click on feeds, you should see this new feed in your My Feeds list. You can view the data by clicking the ambient-light feed name.

Interpreting Your Light Data

Once your sun tracker has been running for a few days, you’ll have a clear picture of the "light profile" for that specific spot. While the raw numbers are interesting, the goal is to translate those peaks and valleys into a plant-friendly plan.

Understanding the Graph

The graph displays Light Intensity on the vertical axis and Time on the horizontal axis.

• The Peaks: Each peak represents the brightest part of the day. A tall, wide peak indicates a long stretch of direct, intense sunlight.

• The Valleys: These show when the area is in shadow, whether from a building, a tree, or simply because the sun has set.

• Consistency: Look for patterns over 3 to 5 days. A single sunny day is great, but seeing how clouds or shifting shadows affect the spot over a week gives you a more reliable average.

Matching Data to Plant Needs

Most plants come with a tag categorized by "Sun Requirements." Here is how to manually calculate which category your spot falls into based on your Adafruit IO data:

Light Category: Full Sun

• Direct Sun Exposure (Daily): 6+ Hours

• What to look for on your graph: A wide, high plateau of high-intensity values that lasts for the majority of the day.

Light Category: Partial Sun / Shade

• Direct Sun Exposure (Daily): 3 to 6 Hours

• What to look for on your graph: A narrower peak, or several smaller peaks if the spot gets "dappled" light through trees.

Light Category: Full Shade

• Direct Sun Exposure (Daily): Less than 3 Hours

• What to look for on your graph: Very low intensity values all day, or only one very brief spike of direct light.

How to Pick Your Plant

1. Now that you have your light data, it’s time to cross-reference it with your "Hardiness Zone." Sunlight tells you if a plant will eat, but your climate zone tells you if it will survive.

   1. Count the "High" Hours: Look at your graph and count how many hours the light stays above a "direct sun" threshold.

      • 6+ Hours: Full Sun (Peppers, Tomatoes, Zinnias).

      • 3 to 6 Hours: Partial Sun/Shade (Root veggies, Herbs, Hydrangeas).

      • less than 3 Hours: Shade (Hostas, Ferns, Moss).

   2. Identify Your USDA Hardiness Zone: Before buying, look up your zip code on the USDA Plant Hardiness Zone Map.

      • This number (e.g., Zone 4 here in Minneapolis) tells you the lowest temperature your area typically reaches in winter.

      • If you find a "Full Sun" plant that is only hardy to Zone 9, it will love your sunny deck in the summer, but it won't survive the winter outdoors. You'll need to treat it as an "annual" or bring it inside.

   3. Check for "Peak Heat" (10 AM to 4 PM): The intensity of the light matters as much as the duration.

      • Northern Climates (Zones 3-5): Morning sun is gentle. You often need those peak afternoon hours to get enough heat for "heat-loving" plants like peppers.

      • Southern Climates (Zones 8-11): Peak afternoon sun can actually be too intense. If your graph shows a massive spike at 2:00 PM in Arizona, you might actually need a "Partial Shade" plant to prevent scorching.

   4. The Perfect Match: Your sun data matches the plant tag (e.g., 6+ hours) AND the plant is rated for your Hardiness Zone.

      • The "Summer Guest": The sun data matches, but the plant isn't hardy to your zone. Great for a seasonal pot, but don't plant it in the ground!

      • The "Reach" Plant: If you have 5 hours of sun but the plant wants 6, try a "Partial Sun" variety instead of forcing a "Full Sun" variety to struggle.