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


Behind 1 exterior wall



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

Express-Checkout as PDF

Pages: 6

Price $2.95
(incl. VAT)

Buy Raspberry Pi Geek

Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content