PORTS Forum

Ports and Interfaces => Serial Ports => Topic started by: GlennP on February 05, 2015, 08:01:31 am

Title: Voltage Level Issues
Post by: GlennP on February 05, 2015, 08:01:31 am

Hi,
I am trying to get a test procedure for some boards that have been tested (rougly!) but are known to be working working from a JPeg I was given I have strapped two boards together (they are IrDA) and the idea was send a string from one to the other, this does not work(!), I went to the circuit diagram and found a TFDU4101 IrDA and a 74LG214 Schmitt trigger but no buffer to bring the logic levels to RS232.  In the photo there does not appear to be a buffer could a TTL to USB convertor have used ? 
Glenn (long time no see!) ;D

Title: Re: Voltage Level Issues
Post by: Jan Axelson on February 05, 2015, 09:40:14 am

TTL voltages will work over short distances (up to a few feet). If you want to use USB, one of the boards will need to function as a USB host, and the other, as a USB device.