Category: Radio

  • FrSky R9M and R9 Slim long range radio system review

    When FrSky R9M long range transmitter and FrSky R9 receiver series started to pop up some time ago, there was a lot of speculations “it is any good?” “is it a Team Black Sheep Crossfire killer” “cheap Crossfire alternative?”. In time, new firmware started to appear, new receivers and so on. And oh yes, EU…

  • iRangeX iRX-IR8M external antenna mod

    Oh boy, I had high hopes for iRangeX iRX-IR8M. Got disappointed badly. So, to make it a little better, let’s get our hands dirty and install an external antenna using an SMA pigtail. Maybe it will make this not so cheap s**t a little better! So let’s have a nice talk in a workshop and…

  • Two things that you HAVE TO change in Betaflight (3.4 and 3.5)

    After weekend tests of Betaflight 3.5 and some discussions with Betaflight developers, here are two things you have to (yes, have to) change in Betaflight 3.4 and 3.5 if you did not did that yet. Worth to do it!

  • DIY Dipole for Crossfire and FrSky R9M

    Details for halfwave dipole for an 868MHz band are quite simple: two 0.8mm copper wires (used for welding) cut to 77mm and solder to the end of coax cable. Here I’ve used RG178 put that thing into a 3D printed casing put antenna tubes around wires. I got mine from here: http://bit.ly/2vHHqDk glue everything together…

  • Crossbow LRS: this one did not went well…

    Sometimes you win, sometimes you lose. This time I’ve lost. Not by much, but always. During testing of my DIY LoRa RC link, radio caught a glitch during a flip few meters above a ground. It was not even a failsafe situation. Link recovered a few milliseconds later, but it was too late and quadcopter…

  • Crossbow LRS: ready for next tests

    Looks like I was able to solve all major known problems with my DIY long range radio system Crossbow. I'm writing known, since no idea what lies beneath… Anyhow… What changed? Quite a lot: I've extended Arduino-LoRa library with ability to transfer full packet in single SPI transaction. Right now, each read of write to…

  • LoRa versus FSK modulation signal spectrum

    LoRa modulation has some advantages. Like superb receiver sensitivity and immunity to interference. Has some problems, true, but at the end, it's a great way to send small packets of data to long ranges using low power. Anyhow, today only one picture: how LoRa spectrum compares to FSK signal spectrum? Like this: Those two peaks…

  • Crossbow LRS: first live test that is almost a success

    Finally, much later than I originally expected, Crossbow LRS, my DIY medium range RC radio link was used to control something that flies. Not much, and not far. It was only my experimental 6″ GPS Racer quadcopter. And I reached only 350m. Small steps, I had no intention to beat and records after all. Just…

  • CC1101 868MHz Wireless Transciever Pinout

    CC1101 is another example of modern radio modules. I might not have the receiver sensitivity or LoRa SX1276, but with proper antennas should give more than 1 km of radio transmission. Recently I got a couple of them, so expect some new projects with CC1101 and Arduino. Now, something that took me some time to…