18v15 and serial (Not TTL)

Hi,

The new 18v15 has USB on board but I need serial because the board I am connecting to has no USB. Now the Qik has TTL and serial because of the voltages between TTL and serial. Now I like to use serial on the 18V15, can I connect them to TTL or can’t I use serial because of the USB?

Thanks!

Regards,

Roel

Hi, Roel.

The Simple Motor Controllers have a serial interface. From the product page:

-Ryan

Hi,

Thanks for your answer, Ryan. But I am still in doubt because I don’t know if you understand my question.

At the manual of the qik is this warning:

Note: Only the SIN line is compatible with RS-232 serial, which is inverted and uses voltages that would be out of spec (e.g. -15 to 15 V). You should not connect RS-232 serial lines to RX or TX. The qik does not provide RS-232 serial output.

Is this problem also there with the TTL connecting directly to a serial port from eg a personal computer? Or should it aways be a TTL (TX and RX) from a source with 3.3V? I don;t like to blow up my 18v15,

Roel

Hi.

You’re right, I didn’t understand your question. I still do not fully understand what you are trying to do. Do you have some separate board that only has TTL level serial communication ability? Or, does it only support RS-232 serial? Are you trying to control both boards with a computer? What is stopping you from controlling one with the computer’s serial port and one over USB? Since I don’t know enough I can’t really suggest what you should do in your situation, but here is some more information about the SMC:

The serial pins on the SMC operate at 3.3V but are 5V tolerant. You should never connect TTL-level signals directly to a serial port on a computer because a serial port on a computer operates at RS-232-level voltages (-12 to 12V). You need either a serial adapter or a USB-to-TTL adapter to interface a computer serial port with the SMC

I would like to point out that you can also send serial commands over the virtual COM port made available through USB. See using the serial interface section of the user’s guide for more details.

-Ryan

Ryan,

Thanks! I couldnt find the following text, so that’s why I posted the question. The following text is the answer to my question.

The serial pins on the SMC operate at 3.3V but are 5V tolerant. You should never connect TTL-level signals directly to a serial port on a computer because a serial port on a computer operates at RS-232-level voltages (-12 to 12V). You need either a serial adapter or a USB-to-TTL adapter to interface a computer serial port with the SMC

Sorry for being unclear, it’s my knowlegde of the english language …

Roel