Buy Shield V1

Buy Shield V2

This is an Arduino / Seeduino Stalker compatible shield to interface to the RFD900, long range radio modem.
If you need long range communications for your project, this will make connecting the RFD900 to a Seeduino stalker, or similar, easy !

The RFD900 Shield requires a RFD900 modem which can be purchased separately.

Shield V1

It has switchable serial source, from either the hardware serial port, or software serial. Shutdown / RTC pins also allow complete shutdown when interfaced with a Seeduino stalker board.

It has the standard Arduino form factor and uses only power, TX, RX and GND pins on the header.

Also available is a user selectable jumper to allow a separate power supply to the modem.

Shield V2

An on board regulator allows direct supply from a 12V battery, or up to a 4S lithium pack.

Shutdown / RTC pins also allow complete shutdown when interfaced with a Seeduino stalker board.

Absolute Maximum Ratings

Value Unit
Vcc Supply Voltage 20 V
Io Current from Regulator 2.4 A
IGN Voltage applied to ignition switch 20 V

Recommended Operating Conditions

Min Nom Max Unit
Vcc Supply Voltage 5.5 17 V
IGN Voltage applied to ignition switch 1.5 3.3 20 V

RFD900 Sheild Pin Configuration

Pin Description
PD0/RX USART Receive pin
PD1/TX USART Transmit pin
PD2/INT0 Interrupt from RTC(Real Time Clock) chip.
PD3/REG_ENABLE Switch to turn the voltage regulator ON or OFF
PD4/SWITCHED_VOL_ENABLE Switch to turn the Switched Voltage Output pin ON or OFF
PD5
PD6
PD7/RX2 Receive pin
PB0/TX2 Transmit pin
PB1/RFD900_SWITCH
PB2
PB3
PB4
PB5
PB6/GND GND
PB7/AREF USART
Analogue In 0
Analogue In 1
Analogue In 2
Analogue In 3
Analogue In 4
Analogue In 5
VIN Supply voltage
GND GND
+5V +5V pin
+3.3V +3.3V pin
RST Reset pin
IGN Ignition pin to turn ON the RFD900 and ATMega328P chip on the Seeduino board
SW_VOL Switched Voltage Output.

The output voltage (VIN or 5V) is selected by placing a jumper between 2 of three header pins.

Modes of Operation

  • The interrupt (INT0) from the RTC chip is active low therefore it should be pulled low in order to turn ON voltage regulator.
  • The REG_ENABLE pin, which is an I/O on the ATMega328P is active high and it is used to turn the voltage regulator ON or OFF. As long as the REG_ENABLE pin is high, the voltage regulator will be turned ON.
  • The SWITCHED_VOL_ENABLE pin, which is an I/O on the ATMega328P is active high and it is used to turn the Switched Voltage Output ON or OFF.
  • The RFD900_SWITCH pin, which is an I/O on the ATMega328P is active high and it is used to turn the RFD900 ON or OFF.
  • IGN is a pin that takes in an external voltage which is used to turn on the voltage regulator at anytime, and as long at this input voltage is greater than 1.5V, the voltage regulator will be in the ON mode.