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20#
发表于 2009-1-17 06:15:24
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只看该作者
来自: 美国 来自 美国
LZ换2501没有用.除非你能写入正确数据.
copy from web:
The "2501" was a DS2501 of 512 bit data space.
The data*** gives specifications to a max programming voltage after
EPROM write instruction of 12V. This means to protect the device from
overvoltage this zener diode connected to the pins must be a 12V zener
and the sereis resistor being a current limiter protecting the diode
in the event that the inner barrel and center pin were to come into
contact.
The DS2502 and 2501 (1kbit and 512 bit respectively) use Dallas Semi.
1-Wire (R) communication protocol. It gets its power from the data
line and when the data line is low a diode protected capacitor supplys
power for its logic circuits, Parasite Power. This means that to
communicate with the DS2502/1 one only needs two lines, a data line
(logic high idle state) and ground. The power to the data/power line
is supplied by the master through a 5k ohm resistor for short cable
lengths. |
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