T89C51AC2
80000
-/23+
原装现货
T89C51AC2
80000
-/23+
原装现货
T89C51AC2
80000
-/23+
原装现货
T89C51AC2
80000
-/23+
原装现货
T89C51AC2
80000
-/23+
原装现货
T89C51AC2
80000
-/23+
原装现货
T89C51AC2
80000
-/2024+
原装现货
T89C51AC2
80000
-/23+
原装现货
T89C51AC2
3588
-/-
原装 部分现货量大期货
T89C51AC2
2800
QQ975246006/08+
原装现货QQ975246006TEL0755-83206583朱素梅
51开发板上的晶振的两个管脚电压46.8mv,是不是坏了?cpu是atmel t89c51ac2。max232的11脚t1in电压5v,晶振的两个管脚电压46.8mv。用atmel flip下载失败,rs232超时。用comspy监视pc的rs232口,结果是pc第一次发送$55,无接收字节第二次发送$55,接收到00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
求救各位高手!!我51的板子是不是坏了?第一次用51的开发板(atmtel t89c51ac2),按照手册用flip下载程序时rs232超时:有几个疑点:1。笔记本电脑没有rs232,所以用了pcmica-rs232的适配器,设定com2,用comspy能检测到发送字节。2。可能问题出在板子上,开发板没有自带电源,要求9-12v都可以,我用标称12v的电源空载电压12.14v,接上板子后12.14v。测下载端口电压,用万用表量电源gnd和下载端口(et-download)之间电压电源gnd和下载端口gnd,rxd, txd, pmod之间电压是0v,电源gnd到pres口2.0mv。测下载端口各个pin之间电压:gnd到pres的电压是-8.53vgnd到rxd的电压是20.7mvgnd到txd的电压是19.3mvgnd到pmod的电压是1.7mv测rs232口各个pin之间电压:gnd到vcc的电压是5v想不到其他检测手段了。原理图是不是我的板子有问题了,求救各位高手!!