Roving Networks RN-374 Manual de usuario descargar pdf (Pagina 21)

Advanced User Manual

www.rovingnetworks.com

rn-bluetooth-um Version 4.77 11/21/2009

809 University Avenue • Los Gatos, CA 95032 • Tel (408) 395-6539 • info@RovingNetworks.com

~ 21 ~

7.3 LED Status

MODE GREEN LED blink rate

Configuring 10 times per second

Startup/Config Timer 2 times per second

Discoverable/Inquiring/Idle Once per second

Connected Solid ON

he YELLOW LED blinks when data is transferred on either the RX or TX pins of the DB9 serial port. It is

a physical monitor of the actual voltage, and is not driven by software in the module.

7.4 Optimizing for Latency or Throughput

The firmware automatically must make decisions on when to forward receive data coming into the UART RX

input out the RF link. The default mode is to optimize for throughput. In some cases, especially with

smaller close spaced incoming data packets, the data can get split, with partial packet forwarded and other

data coming later. Unfortunately, Bluetooth has algorithms that can cause significant latency between

packets ( > 10ms) at certain times. If the host protocol expects data to come as contiguous bursts and has

short timeouts, this can cause errors. There is another method of optimization, which will force the radio to

attempt to keep small bursts of data together. In this mode we optimize for latency. To enable this mode,

there is a special debug command. The command is “SQ,16”. This sets the latency bit in the firmware. To

disable this mode. Use the command “SQ,0”. The value of the register can be read with the “GQ”

command, and will read back as HEX, even though it is set as decimal.

7.5 Limitations of 7 Bit Data Mode

Roving Networks firmware supports selectable 7 bit data mode, using the “S7,1” command.

Unfortunately the Bluetooth hardware does not support 7 bit data, so this function is accomplished in the

firmware application. While completely functional, the performance in 7 bit mode is less than ideal, because

software emulation is required to make this work. Hence, there is a noticeable latency and character per

second processing limit in this mode. Therefore it is not recommended that this mode be used if the desired

serial baudrate is greater than 9600 baud.

1 2 ... 16 17 18 19 20 21 22 23 24 25 26 ... 31 32

Sin comentarios

Roving Networks RN-374 Manual de usuario Pagina 21