Datasheet

DocID026906 Rev 3 15/27

SP1ML Module operation

3 Module operation

The SP1ML module is provided with firmware that supports wireless serial cable

replacement. There are two operational modes, command mode and operating mode. The

command mode allows module configuration and status interrogation using an extended

‘AT’ style command set. In operating mode the module serves its primary purpose as a

wireless transceiver. Following power-up or reset, the module starts in operating mode with

the current configuration loaded from EEPROM.

3.1 Operating mode

In operating mode, data received from the host on the UART interface will be wirelessly

transmitted by the SPIRIT1 radio using the current configuration settings for frequency, data

rate, modulation and output power. Conversely, any data received by the SPIRIT1 that

meets the configured filtering criteria will be output to the UART interface.

Care must be taken to ensure that the escape sequence to enter command mode does not

occur in the data stream sent by the host to the UART interface.

3.2 Command mode

In command mode, the module will accept commands to configure module settings and

interrogate module status. To enter command mode, the ‘+++’ escape sequence is issued to

the module from operating mode. The escape sequence should be preceded by minimum

delay of 500 milliseconds where no other data is transmitted. The three ‘+’ characters of the

sequence must be sent within 500 milliseconds of each other. The module issues the

response ‘OK’ if command mode is entered successfully.

Commands issued to the module are in ‘AT’ style format, and use ASCII characters, starting

with ‘A’ and ‘T’, then one or more characters for the specific command, followed by any

additional command specific data and terminated with a carriage return <CR>.

The delay between each consecutive character of a command must be less than 8 seconds,

else the module will time out and discard any characters already received.

If the module receives an invalid command, it will send the ‘ERROR’ response. All

responses issued by the module are terminated with a line feed and carriage return,

<LF><CR>.

3.3 Command reference

Table 9: Command reference provides a summary of the AT commands available for

module configuration. A detailed description of each command is provided following the list.