Usb to uart

Hi, i have a project where i am flashing a motorcycle trough an serial to ttl ftdi cable.. im wondering if i can use the arduinos uart pins for that too.. i read about switching the reset pin to ground and connecting to the TX/RX0.. but thats not what i want because i need the arduino keep running doinv other things. It would be usefull to clone the uarts too to add a bluetooth ecc transmitter. The Problem is that i dont know the speed(baud).. because of that it needs to be verry fast...

Just what do you have that needs to talk to the Arduino. Which arduino/AVR are you using.

Mark

The Problem is that i dont know the speed(baud).. because of that it needs to be verry fast...

I'm interested in why you jumped to that conclusion.

i am flashing a motorcycle

Better than flashing school kids, I guess.

Hi, its a Mega2560 clone from sainsmart... I think it is possible that the ecu talks in other speeds, i dont know the exactly speed.. Because of that i cant write a simple serial.read to serial.print or write... or is it working if i do serial.begin(500000) and the program uses maybee 9600 or something...

Serial speeds must match on both sides of the wire. You can't just try "faster" to make it work.

If you truly don't know what the speed is and you can't get it from the manual then you are going to have to try every speed, one at a time, until you get good-looking data. Note that the wrong speed will get some data but it will be garbage. Plus, depending on the actual serial data, good data may look like garbage to a person even when it's perfect for a computer (or Arduino) to decode.

There is a list of standard Serial speeds (1200, 4800, 9600...) but for something like a motorbike it could be anything, even 9601.

Yeah thats my problem.. is there maybe a way like decoding the input and sending it 1010.. at the same timetime?

is there maybe a way like decoding the input and sending it 1010.. at the same timetime?

Is there maybe a way you could phrase that question in English?

i mean, read High low on the serial input and send it to the serial output whitout Serial.something...

If the port generates traffic, you can poll the pin in Gpio mode, and measure the shortest bit time you see. That's likely to be one bit, and since it's been measured, you can convert it back to a baud rate... It might be easier to see on a scope, but the arduino could do it...