Sending your data through the air
What About Transmitter Range?
The Serial RF Pro is rated for 600 meters in free air (i.e., no obstructions along a line-of-sight path). Anything in your way reduces the received power and the range. To test the range, I took the solar-powered transmitter system on a walkabout (see Figure 7) and ran two tests: one with the receiver behind three interior walls and a single exterior wall and one with the receiver behind only one interior wall. I specifically looked for continuous data flow. I found that I could walk 5% - 10% further than the maximum reliable distance and still get a packet now and again. Putting my arm up in the air also increased the distance. Height really helps in this kind of a situation.
Figure 7: Solar-powered transmitter on a walkabout.
Table 1
Maximum Transmission Distance
| Receiver Condition | Maximum Transmitter Distance |
|---|---|
| Behind 3 interior walls/1 exterior wall |
220m/720ft |
| Behind 1 exterior wall |
438m/1,437ft |
Conclusion
Once again, I am amazed at what can be done with inexpensive hardware and, once I had the Grove Pro Mini LP built, how easy and fast it was to build the WXLink transmission system. I have run out of room in this column, but I have a lot more information on this project, some of which you can find at the SwitchDoc Labs website [12] including a lot more discussion about the solar-powered version.
Buy this article as PDF
Pages: 6
(incl. VAT)
Buy Raspberry Pi Geek
US / Canada
UK / Australia
Related content
-
A new way of no-solder prototyping
The Grove system's standardized connector and multitude of devices allow quick and easy project prototyping with your favorite small-board computers.
-
Measuring air quality with the Raspberry Pi
Monitor your environment with a Raspberry Pi and an air quality sensor.
-
Getting more power from your solar panels
How much extra power can a solar panel collect by tracking the sun? SwitchDoc Labs puts it to the test.
-
IoT on Your Raspberry Pi
The SunIOT project attaches a Grove base unit with a light sensor to a Raspberry Pi to measure various components of the light spectrum.
-
SunRover Part 4 – Adding a Pi Camera and Diagnostics System
A Raspberry Pi Camera module and a diagnostics system allows SunRover to see and check that all systems are go.
