tpow 0.2.0

Tiny 1-wire utility. 100% pure python, USB9097 specific.

porvides

• Minimal 1-wire protocols for USB9097.

• Basic rom search algorithm (use recursion).

has dependencies and limitations

• 100% pure python, requires pyserial to control UART.

• support external power mode only. parasite power mode is not supported.

• tested on Windows10 PC + USB9097 (1-wire adapter).

Adapters/Sensors/Devices

• USB9097 (1-wire adater with Vcc supply, PCsensor.com ShenZhen/China)

• DS18B20, DS2438 (Dallas/Maxim)

• Humidity Sensor HIH-5030 + DS2438Z+ (TaaraLabs Estonia)

Usage

Check examples/ folder which contains some tests. pip tpow will install it under Lib/site-packages/tpow. If you can not find examples/, download source package *.tar.gz and check it.

Get a ROMID (one 1-wire device on the bus)

import tpow.usb9097

bus = tpow.usb9097.USB9097('COM3')
bus.cmd_reset()        # 0xE3, 0xC1
bus.dat_write([0x33])  # read-rom
ans = bus.dat_read(8) # little-endian (family + SN[6] + CRC)
print(['%02X'%ord(a) for a in reversed(ans)]) # big-endian

Get all ROMID’s (search all ROM’s on the bus)

import tpow.usb9097

bus = tpow.usb9097.USB9097('COM3')
xx = tpow.usb9097.search_roms(bus)
for x in xx:
    print(x)

Get temperature / ds18b20

import tpow.usb9097
import tpow.device
import tpow.sensor

bus = tpow.usb9097.USB9097('COM3')

# do temperature conversion and get scratch-pad
spad = tpow.device.ds18b20_skip_rom(bus)

# decode temperature
t = tpow.sensor.ds18b20_temp(spad)

print("SPAD : " + " ".join(['%02X' % ord(a) for a in spad]))
print("%8.3f [degC]" % t)

Todo

• check temperature conversion completed status. (currently, wait 1 sec for each temperature conversion)

• check operation finished status bit.

• check CRC.

• refine data type of parameters (bytes, string, list of single bytes…)

License

Copyright (c) 2018 Kenich SHIRAKAWA This is licensed under MIT license. See Licence.txt for more information.

Links

1-wire adapter USB9097 (PCsensor)

Humidity Senosr (TaaraLabs)