Transceiver Connection

Transceiver Connection

The below table reports the connection for the supported transceivers, you need this details if you are manually wiring the transceiver on your host microcontroller.

Wiznet W5100 / W5200 / W5500

The Wiznet W5100 (or W5200 / W5500) is an Ethernet transceiver generally used in the Arduino Ethernet Shield and Arduino Ethernet, if you have a module to wire manually use the following connection:

Microcontroller	Communication Protocol	Chip Select
ATmega328, ATmega32U4, ATmega2560	SPI	10

Each microcontroller use different pin for SPI, refer to Arduino SPI for details.

Microchip ENC28J60

The Microchip ENC28J60 is an Ethernet transceiver generally used in unofficial Arduino Ethernet Shield, if you have a module to wire manually use the following connection:

Microcontroller	Communication Protocol	Chip Select
ATmega328, ATmega32U4, ATmega2560	SPI	10

Each microcontroller use different pin for SPI, refer to Arduino SPI for details.

Nordic nRF24L01 and nRF24L01+

The Nordic nRF24L01 and nRF24L01+ are wireless 2.4 GHz transceiver available as dedicated module that need to be manually wired to the host microcontroller. It use SPI as communication protocol, the drivers used by default the Hardware SPI or as option the Software SPI.

Microcontroller	Communication Protocol	Chip Select	Enable
ATmega328, ATmega32U4, ATmega2560	Hardware SPI	8	7

Each microcontroller use different pin for SPI, refer to Arduino SPI for details. The SPI protocol allow multiple slaves as long as they use different Chip Select pins, but in some cases has been observer that nRF24L01 radio doesn't work properly while sharing the SPI with other transceivers. For this reason an option is communicate with nRF24L01 using a Software SPI, this of course consume more resources (FLASH and RAM).

There are several Software SPI library, Souliss doesn't bundle any Software SPI and you need to install it separately. A suggested Software SPI is included in Digital IO library.

Enable the Software SPI as follow

#include <DigitalIO.h>
#define	nRF24SPI_INSKETCH

SoftSPI<SOFT_SPI_MISO_PIN, SOFT_SPI_MOSI_PIN, SOFT_SPI_SCK_PIN, SPI_MODE> nRF24SPI;

setup()
{
 ...
}

You need to specify the MISO, MOSI and SPI pin that Software SPI will use, the CS and EN pins remains the 8 and 7.

Max frame cutout The nRF24L01 radio has constrains on maximum frame lenght and this result into a cutout at 32 bytes of payload. Considering a 11 byte of header (5 for MaCaco and 6 for vNet) the result is that no more than 21 bytes of payload and so 21 SLOTS can be transferred.

HopeRF RFM69HW

The HopeRF RFM69HW is a wireless 900 MHz transceiver used in Moteino boards and available as external radio, if you have a module to wire manually use the following connection:

Microcontroller	Communication Protocol	Chip Select
ATmega328, ATmega32U4, ATmega1284	SPI	SS

Each microcontroller use different pin for SPI and SS, refer to Arduino SPI for details.

The drivers for RFM69HW use the default SS pins, if you are using an Ethernet transceiver the default pins reported before are no longer applicable, the following applies:

Microcontroller	Ethernet Transceiver	Communication Protocol	Chip Select
ATmega328	W5100/W5200	SPI	7
ATmega32U4	W5100/W5200	SPI	11
ATmega1284	W5100/W5200	SPI	49
ATmega328	W5500	SPI	8
ATmega32U4	W5500	SPI	11
ATmega1284	W5500	SPI	49
ATmega328	ENC28J60	SPI	7
ATmega1284	ENC28J60	SPI	0

USART (RS485)

The microcontroller has an embed USART that can be used for direct communication or via an RS485 transceiver, this vNet driver is based on the default Serial library from the Arduino cores. Some microntrollers has multiple USART peripherals, you can define use any of the available for the communication via USART.

Microcontroller	USART	Pins (RX, TX)
ATmega328	Serial	0, 1
ATmega32U4	Serial1	0, 1
ATmega2560	Serial,	0, 1
ATmega2560	Serial1,	19, 18
ATmega2560	Serial2,	17, 16
ATmega2560	Serial3,	15, 14
ESP8266	Serial	1, 3

Define the USART to include in the configuration option at top of the sketch (before #include "Souliss.h")

#define USARTDRIVER_INSKETCH
#define	USARTDRIVER	Serial	// or any other USART to use

Special option are available in conf/usartUsrCfg.h as the baudrate, those are generally useful in case of RS485 communication

Option	Description
USART_TXENABLE	Activate the USART_TXENPIN pin before any transmission
USART_TXENPIN	The pin to use to active the transmission
USART_COLLISION	Enable or disable the collision avoidance
USART_CRCCHECK	Enable or disable the CRC check

Max frame cutout The USART has a cutout that is used to avoid a lack of performances of the Collision Avoidance build in the software driver, this result into a cutout at 36 bytes of payload. Considering a 11 byte of header (5 for MaCaco and 6 for vNet) the result is that no more than 25 bytes of payload and so 25 SLOTS can be transferred.

Broadcast transceiver Any USART broadcast transceiver can be connected to the USART and used with this vNet driver, is required the broadcast behavior (all connected devices shall be able to listen), this driver has been tested with:

• RS485 Transceiver
• Ciseco XRF 900 MHz Radio