If you have many toy quads or if you are into Silverware, you probably know about or even use the IRX6 or MTX9D multiprotocol modules.
These modules allow you to bind to and control many toy quads. And theyâ€™re quite cheap. But they have a major limitation: poor range. So we will build a better but still-affordable NRF24 multiprotocol module.
But the most important component is the excellent NRF24 multiprotocol firmware for the Arduino by Goebish. This project wouldn’t have been possible without his firmware and his help and guidance. Thanks, Goebish!
Additionally, the 3.3V out pin of the Arduino nano does not have enough power for this RF module so you will need a separate 3.3V power module to power the RF module
Finally, the PPM signal voltage output from some transmitters may be too high for the Arduino Nano, so to be safe you need a 10k ohm resistor in-line with the PPM signal wire. This give you input voltage protection up to +15.5VDC and down to -10.5VDC. More info here.
Wire according to the diagram below.
Upload the NRF24 multiprotocol firmware to the Arduino Nano.
Connect the power, ground, and PPM lines to your TX.
Create a model on your TX with PPM output
While holding the appropriate stick pattern, power up your TX. Last used protocol is automatically selected if stick is in neutral position so thereâ€™s usually no need to do this every time.
Release the stick(s).
Arm if necessary
Thatâ€™s it. You now have a budget multiprotocol module with longer range.
When you start thinking (fantasizing?) of being a drone racer, you will want to know how fast you are around your home track: You need a lap timer to record the time elapsed from the time you leave the starting gate to the time you pass it again. There are usually two ways of doing this: attaching a transponder (additional equipment) or using the RF signal of the VTX (no additional equipment). Needless to say, we will be doing the latter approach.
The key component is the RX5808 module which is the heart of most, if not all, video receivers in the market. The module receives the VTX signal and converts it to audio and video. It also measures and provide the signal strength (RSSI value). What the lap timer does is to compare the RSSI with a set threshold. If the RSSI value is above the threshold, the corresponding drone is considered passing a finish gate and the time elapsed is recorded.
There are two maybe three active lap timer projects online: Chorus RF Laptimer and PIDFlight Lap. For this project, we will adopt the schematic and use the software and firmware of PIDFlight Lap. However, to keep things simple for now, we will simplify the schematic and use connected mode where the lap timer is connected directly to and powered from a computer or Android phone (via OTG).
If you’re working with the PCB, you’ll need the following:
Review revised schematic
Prepare header pins for the RX5808 module. You need 9 pins
Solder header pins to RX5805 receiver module
Prepare buzzer. The short leg is ground, the long leg is positive. This is also indicated on the top of the buzzer body.
Following the schematic, insert the components to the breadboard
Install Arduino Nano driver
Install Arduino IDE
Install the appropriate firmware.For Chorus RF Laptimer, you can download the Arduino sketch, load it on the Arduino IDE, and upload to the Arduino nano. For PIDFlight Lap, you will get a .hex file and you will need to upload manually. You can use XLoader on Windows or Hex Uploader on the Mac. Or use avrdude directly: