ON 20050909@4:29:34 PM at page: http://www.piclist.com/techref/io/serial/ttl-rs232.htm#38027.3021412037 James Newton[JMN-EFP-786] published post 38027.3021412037 http://www.botkin.org/dale/rs232_interface.htm This can be done SO much more simply. Don't get hung up on bipolar transistors; this is a switching job, thre are better tools. Use two small MOSFETs and two resistors and do it the easy way! |Delete 'P-' before: '' but after: '