Serial Port, SPI

Hi. I�m designing a new application with a RCM3700 board. I need know if serial ports of module are 5V tolerant. I don�t have 3.3V in my board. ANother question: Can I use any pin with SPI lib of dynamic C?. Many thanks.

Serial ports are capable of handling 5V. (but i’m using RCM 2000, hope the system is the same there)

I do not know about SPI. I also needed to do some SPI and failed. If you can help, please tell me. I use DC 7.04 and 6.0

If you really need 3.3V, use the 7833 regulator. Its easy to use.

The inputs are 5V tolerant and will work fine. The outputs can be a problem to some devices as they only drive to +3.3V. Check the switching threshold on the device you plan to work with, if it switches in the 0.8 to 1.8V range, you should be okay. If it switches at +2.5V, then this could cause problems and you probably want to ‘boost’ the output pins by running them through a level converter chip or some transistors to create a 0-5V output.

On the 3700, serial ports B thru D can be used as SPI ports. The clock pin for each of these are PB0 (B), PF1 (C) and PF0 (D).