[RC232] I’m not currently using flow control, and am having an issue in correctly identifying the start of each 64 byte packet. My understanding of CTR/RTS is that they wouldn’t help in this? Is there a signal that shows the start of each packet?

The RC1180 use Asynchronous UART and flow control is no needed on the host MCU as long as the UART speed is correct. The start of the incoming packet will be the first Start bit on TXD.

Optional Hardware flow control lines are:

CTS pin – Clear to send: The low-asserted CTS pin provides flow control for the module. When CTS is asserted (low), serial data can be sent to the module for RF transmission. If the module is busy, like during RF data transmission or reception, the CTS pin will be de-asserted (high) to stop any data transfer to the module.

RTS pin – Ready to send: When RTS is asserted (low) the host allow data to be sent from the module to the host. The host can stop the module from sending data by de-asserting (high) the RTS signal. Note that if the module has data waiting in the receive buffer, it will not be able to receive or transmit further data until the RTS has been asserted and the data in the buffer is transferred to the host.

RXTX pin – RS485 driver control: RXTX is low when the module can receive data on RXD. RXTX is high when the module is transmitting data on TXD and additionally 1 ms for the module to turn from TXD to IDLE mode (see Timing Information in the module data sheet). The RXTX pin is normally connected to the /RE and DE pins on the RS485 driver circuit.

Last Update: September 22, 2017  

September 22, 2017   1007    RC232 Q&A