SparkFun Forums

[m_ahlenius]

Hi,

I looked at the datasheet for your Apollo AP-MSR200 magnetic card reader, but cannot find which voltages this unit uses on its RS-232 interface. I am not planning on using this with a PC serial port, but a special port which requires 3.3 vdc signalling.

Also what is the minimal power supply voltage required by this unit?

thanks very much

'mark

[n1ist]

It uses RS232 voltage levels. It also gets power from the serial port, so it likely needs the handshake lines too as a DC source.

[Philba]

if that's true then it may not work on that port.

[m_ahlenius]

Right, but there are various levels for true RS232, they range from +/- 3 to 15 volts.

What I need to know is what is the supply voltage for this device? TTL type power - like 5 vdc, or what?

Some rs232 devices have signals which operate in the TTL ranges of 0-5 vdc as well.

This information is missing from the data sheet. Does anyone know for sure?

thx