<>前天夜晚忙到半夜,作了一根gps到pda的转换线。专用接口到串口。</P>
<><img src="attachments/dvbbs/2004-5/200451021324744.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2004-5/200451021324744.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />
别看是串口线,但因为pda输出的是ttl电平,所以需要在中间有电平转换电路。用max232和4颗电容搞定。最难的是pda的借口定义找不到,没有示波器,只能根据电路板判断和试验,最终找出了TTL的in和out端口。</P><img src="attachments/dvbbs/2004-5/200451021627755.jpg" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2004-5/200451021627755.jpg\');}" onmousewheel="return imgzoom(this);" alt="" />