voltOTG

Python class to interface with a USB volt meter named voltOTG

Background

While surfing online I spotted a 15$ volt meter called "voltOTG" from china that connects to a smartphone, I thought it sounded fun and ordered it.

When I got it I started playing with it in the android app and saw some potential for use with for example a raspberry pi for logging voltages. So I reversed engineered the usb communications and wrote them up as a python class

Install

From Git

git clone https://github.com/gbit-is/voltOTG.git
cd voltOTG
pip3 install -r requirements.txt

From Pip

pip3 install voltOTG

Project on PyPi

How to use

Automatically connect to the voltOTG reader

import voltotg
reader = voltotg.voltOTG()
reader.autoConnect()

Manually connect

import voltotg
reader = voltotg.voltOTG()
reader.connectDevice("/dev/tt...")

Reading and printing the voltage every 10 seconds

import voltotg
from time import sleep
reader = voltotg.voltOTG()
reader.autoConnect()
while True:
  volts = reader.reatVolt()
  print(volts)
  sleep(10)

Execute serial command (basic)

import voltotg
reader = voltotg.voltOTG()
reader.autoConnect()
command = "ReadVersion"
reply = reader.bcom(command)
print(reply)

Execute serial command (With empty reply fail-safe*)

import voltotg
reader = voltotg.voltOTG()
reader.autoConnect()
command = "ReadVersion"
reply = reader.scom(command)
print(reply)

Commands avaivable within voltOTG

(1): getVersion() will return the version number, getVersion(list=True) will provide both version and name, getVersion(name=True) will return the name only, getVersion(version=True) will do the same as providing no argument

(2):readVolt() will return a voltage reading in mV, readVolt(list=True) will provide more info from the command, readVolt(raw=True) will return the raw reply from the device, readVolt(info=True) returns a weird one-off inside-the-code documentation, readVolt("voltage=True") does the same as no arguments,

(3) readScale() will return the scale value, readScale(list=True) will return a list of scale and calib, readScale(raw=True) will return the raw reply from the device, readScale(calib=True) will return the calib value, readScale(scale=True) does the same as providing no argument

Commands on device not in voltOTG

Due to me having no idea how to handle consistant data streams the first 2 commands were not implemented in the package, the last one was simply left out since I thought it was a bad idea to implement an automatic Zero-ing function, not sure if I agree with that anymore though ........