I am trying to interface the 8-pin bluetooth module Promi-ESD-02 with the Keil MCB2140 ARM7 board. The bluetooth module communicates with the MCU using UART (so I need to connect it to RxD0, TxD0 pins of the MCU).
My problem is that there are no jumpers for the RXD0, TXD0 or RXD1, TXD1 so that I can safely remove the MAX563 IC (that converts +/- 12V to logic levels) from the circuit. In other words, I can't connect the bluetooth module directly to the MCU pins.
I was thinking about Software UART. What other options do you recommend? I'm a student working on this project and I don't have price/performance limitations, or any other hw/sw tradeoffs restrictions.
P.S. : I've already written a UART0 module - COM0, so it there a possibility to use that?
Schematics: http://www.keil.com/mcb2140/mcb2140-schematics.pdf
Thank you
Wait a minute. The guy is a student, and his requirements are somewhat different than ours. He needs something that works. Why not implement a software UART, then?
See here - you only need to fill in the missing pieces (timer...) but that should be a no brainer for you:
supp.iar.com/.../
I think the RS232 transceiver approach is likely yo have (far) better chances of success...
It will also be valuable in tests/experiments with a PC...
Thank you for the responses. I think I will try both methods (Serial UART and RS232 transceiver) just to see how it works. Got a MAX3232 so there should be no problem.
Has anyone tried to program the LPC2148 with bluetooth? Can it only be done with a bootloader? Otherwise I need to control somehow RTS and DTR signals (from RS232) used by Flash Magic for in-system programming.