hello,
how to adapt programmator ds1821 , the schematic it's for serial PC
how to modif for a usb > ttl uart (ft232) because the serail pc it's +/-12v
thank you
You will find it very difficult to interface RS232 to 1-Wire like that. It is more than just the voltages that are different, you need to accurately control the timing of read and write cycles which a normal serial port cannot do.
Not quite right. Interfacing 1-wire devices with UART signals is well possible, also suggested by Maxim-Dallas, see appended AN. The schematic is quite similar to post #1.
Interfacing 1-wire with negative UART logic is even simpler because it doesn't need inversion, only a low voltage (e.g. schottky) diode to implement open drain output. As far I'm aware of, it's not necessary to switch supply voltage, connecting 5V should be sufficient.
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If you want to use the existing hardware, use CMOS inverters to invert RxD, TxD and RTS. Short 1k and supply 5V to DTR.
Attachments
app177 Programming 1-Wire EPROM and EEPROM Memory Devices Using a PC.pdf
ok , thank you , i've usb DS9097 for link with 1wire , but onewireviewer software is not for ds1821
i see DS1701K software is for ds1821
but it's obsolete ,
can anyone tell me where to download it?
or other sofware for the DS1821
thank's