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PIC18F2420 I2C
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新會員
 
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請問一下，我用pic18f2420的GPIO去拉H/L 來實現I2C
不是用內建的I2C function. 用的pin是 RC3=SCL ，RC4=SDA - 我接到一I2C的Slave，可是我發現我的slave回ACK時無法將我用4.7K PULL up到3.3v的high level給完全拉到GND，有往下拉，但只有往下拉一點點而已 -- Orz 導至我主程式在判斷ACK時錯誤(認定HIGH LEVEL)， 我有試著把PULL UP的電阻拿掉，但也是一樣... 雖然我後來不判斷ACK，我的SLAVE也能Work 但如果我要讀值回來，就只能讀到FF. 請問這是為什麼?? 是軟體設定要修改還是硬體要做修正... 感謝各位。
發表於: 2009/2/7 16:07
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