Help please with connect DS2450 to Omega-2 +
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Yes, DS18B20, if using local power (as opposed to parasite power thru 1-wire), min voltage is 3V. Thus should work with a 3.3V 1-wire system, either in local power or parasite power configuration.
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@ccs-hello
Temperature sensor DS18B20 perfectly shows the temperature:root@Omega-D90D:~# cat /sys/devices/w1_bus_master1/28-0000053f2316/w1_slave 9e 01 4b 46 7f ff 02 10 56 : crc=56 YES 9e 01 4b 46 7f ff 02 10 56 t=25875
or
root@Omega-D90D:~# awk -F= '/t=/ {printf "%.03f\n", $2/1000}' /sys/devices/w1_bus_master1/28-0000053f2316/w1_slave 25.937
Thus, paragraph 1 has been verified. What should I do next?
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Are you supplying Vdd (3.3V) power to DS18B20 (test #2) or
just using parasitic power (test #1)?
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@ccs-hello
I supplying DS18B20 power 3.3 v. No parasitic power.
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Now it's the hardware thing.
I'd recommend PCA9306 and using its SDA (bidirectional) channel.
MOSFET based level shifter is just a hack.
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@ccs-hello
I connected the DS18B20 according to this diagram:
And everything works.So, the problem in the DS2450?
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Figure 1 in post 1 needs a 4k7 pull up resistor on A/D's 1-wire data pin.
1-wire is using open-drain bus for communications.
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@ccs-hello
I added a 4.7-kOm resistor to the circuit, Omega sees the ADC, but does not read the data from it. Maybe the data should be read somehow differently?root@Omega-D90D:~# cat /sys/devices/w1_bus_master1/w1_master_slaves 20-0000000a2208 root@Omega-D90D:~# cat /sys/devices/w1_bus_master1/20-0000000a2208/w1_slave cat: can't open '/sys/devices/w1_bus_master1/20-0000000a2208/w1_slave': No such file or directory
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One thought:
find a 5V I/O tolerable Linux box (full fledged LINUX implementation would be better), retest the 1-wire code on that A/D chip.No 5V - 3.3V bi-direction level shifter in the interconnect.
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Or ask the author of the custom 1-wire code.
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@ccs-hello
In datasheet on DS2450 written different commands. But I do not know how to introduce them.
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@CAP-33 In WHAT?
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@William-Scott
In datasheet