Connecting the Radio

created by hek , updated

The NRF24L01+ and RFM69 transceiver communicates with the Arduino board via the SPI interface. It is important to always feed the radios with a stable power source of 3.3V.

Refer to the notes about using a regulator or a coupling-capacitor below.

Wiring the NRF24L01+ Radio

NOTE: The input pins on the NRF24L01+ is 5V tolerant. However, you cannot feed the module with more than 3.3V on VCC. If you use a 5V Arduino you have to use a step-down regulator!

Arduino NRF24L01+ Color
GND GND Black
5VReg -> 3.3V VCC Red
9 CE Orange
10 CSN/CS Yellow
13 SCK Green
11 MOSI Blue
12 MISO Violet
2 IRQ Gray

Note: The IRQ is currently not used by the MySensors library so it can be left un-connected. If you are using an Arduino Mega, see this post for instructions.

Wiring the RFM69 Radio

NOTE: The NSS, MOSI and SCK are not 5V tolerant on RFM69. You will need to use a level converter if you're using a 5V Arduino.

Arduino RFM69 Color
GND GND Black
3.3V VCC Red
10 NSS Yellow
13 SCK Green
11 MOSI Blue
12 MISO Violet
2 DI00 Gray
ANA Antenna

RFM69 Antenna

IMPORTANT: You MUST attach an antenna to the board. Aside from not working without an antenna, transmitters can be damaged if they transmit without an antenna present.

By cutting a wire to the proper length you can create a simple antenna for your RFM69 radio. Depending on the frequency of the radio, the antenna has to be cut to different lengths. Cut the antenna slightly longer to give room to solder it to your board. You can always trim it once soldered.

Frequency Length (in) Length (mm)
434 MHz 6.47" 164.7 mm
868 MHz 3.22" 82.2 mm
915 MHz 3.06" 77.9 mm

Above antenna length represent 1/4 wave. There is also commercial antennas to buy in proper length.

Connecting a Decoupling-Capacitor

If you experience bad reception or if transmitted data never reaches destination, try adding a decoupling capacitor of 4.7µ - 47µF (the exact size usually doesn't matter) across the radio's 3.3V and GND.

Capacitor Radio Comment
- side GND Marked Black on radio
+ side 3.3V Marked Red on radio

The side with "< - < - "-marking should be connected to GND

Connecting a Voltage Regulator

NOTE: If you are using the 5V version of Arduino Pro Mini (that lacks the 3.3V regulated output) you'll have to connect a 5V->3.3V regulator between the Arduino and Radio.

Arduino Regulator Radio
5V Vin
GND GND GND
Vout VCC

Datasheets

NameSize# Downloads
nRF24L0Plus.pdf1.06 MB501
RFM69HW-V1.3.pdf1.17 MB262
sx1231h.pdf962.48 kB171

Shopping Guide

100pcs electrolytic capacitors
Assorted values. 0.1uF-100uF. Use capacitors to stabilize power to the radio.
941 available - $4.28   Buy
In stock - $2.09   Buy
10pcs 433Mhz Antenna
For RFM69 Modules
299 available - $1.38   Buy
In stock - $4.30   Buy
10pcs 868Mhz Antenna
For RFM69 Modules
57 available - $4.98   Buy
In stock - $1.90   Buy
10pcs 915MHz Antenna
For RFM69 modules
31 available - $2.84   Buy
In stock - $1.90   Buy
10pcs LE33ACZ 5V-3.3V Step Down Regulator
Regulator for adjusting the power to the radio when using 5V Arduino Pro Minis. Easy to solder and/or use on a breadboard.
383 available - $7.95   Buy
In stock - $7.44   Buy
10pcs NRF24L01+ 2.4GHz Wireless Transceiver
This is what enables your sensors to communicate wirelessly across a nominal range of 60 meters.
2252 available - $9.99   Buy
In stock - $7.75   Buy
20pcs 662K 5V-3.3V Step Down Regulator
Inexpensive regulator for adjusting the power to the radio when using 5V Arduino Pro Minis. Warning! Very small and hard to solder.
533 available - $0.99   Buy
Stock unknown   Buy
AMS1117 5V-3.3V Step Down Module
Regulator for adjusting the power to the radio when using 5V Arduino Pro Minis. Solder free.
4214 available - $0.99   Buy
In stock - $0.43   Buy
Logic Level Shifter
Bi-Directional logic level shifter. 5V to 3v3. 4 Pins.
62 available - $0.99   Buy
In stock - $2.70   Buy
NRF24L01+ Socket Adapter Board
Another adapter for Arduino Pro Mini 5V that provide 3.3v regulated power to the radio. Solder free.
5860 available - $0.99   Buy
In stock - $0.72   Buy
NRF24L01+PA+LNA Antenna version
This radio has an extended range of up to 1000 meters according to spec. Use this if you need to cover a greater distance or area.
10757 available - $2.80   Buy
In stock - $1.90   Buy
RFM69 433Mhz Transceiver
HopeRF RF69 module. Select frequency band on aliexpress.
2393 available - $3.90   Buy
Stock unknown   Buy
RFM69 868Mhz Transceiver
HopeRF RF69 module. Select frequency band on aliexpress.
700 available - $4.25   Buy
Stock unknown   Buy

Comments