https://github.com/sanmai/usb-scale-reader

Read weight from an USB scale (from Stamps.com or DYMO) in Linux
https://github.com/sanmai/usb-scale-reader

digital-scale

Last synced: 2 months ago
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Read weight from an USB scale (from Stamps.com or DYMO) in Linux

• Host: GitHub
• URL: https://github.com/sanmai/usb-scale-reader
• Owner: sanmai
• License: mit
• Created: 2015-10-22T05:16:43.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2021-01-06T05:40:24.000Z (almost 4 years ago)
• Last Synced: 2024-10-07T21:09:06.886Z (3 months ago)
• Topics: digital-scale
• Language: PHP
• Homepage:
• Size: 35.2 KB
• Stars: 30
• Watchers: 6
• Forks: 10
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

        
# USBScaleReader

[![Latest Stable Version](https://poser.pugx.org/sanmai/usb-scale-reader/v/stable)](https://packagist.org/packages/sanmai/usb-scale-reader)

This library lets you read weight from a standard USB scale using pure PHP. 

 

Could be ported to other languages with ease, should they have `unpack()`

 

Tested with:

 - Stamps.com Stainless Steel 5 lb. Digital Scale

 - DYMO M25 25 lb Digital Postal Scale

See [read_stupid.php](example/read_stupid.php) or [usbscale.c](example/usbscale.c) if you want to understand how it works at a glance.

### Usage

    composer require sanmai/usb-scale-reader

    

And then:

```php

$reader = \USBScaleReader\Reader::fromDevice('/dev/scale');

$weightInGrams = $reader->getWeight();

var_dump($reader, $weightInGrams);

```

Sample output:

	class USBScaleReader\Reader#2 (5) {

	  public $report =>

	  int(3)

	  public $status =>

	  int(4)

	  public $unit =>

	  int(2)

	  public $exponent =>

	  int(0)

	  public $weight =>

	  int(144)

	}

	int(144)

### udev rules

Add to `/etc/udev/rules.d/80-persistent-scale.rules`:

    KERNEL=="hidraw*", ATTRS{manufacturer}=="Maker Name", SYMLINK+="scale"

    KERNEL=="hidraw*", SUBSYSTEM=="hidraw", MODE="0664", GROUP="plugdev"

Maker name is either `Stamps.com` or `DYMO`.

And then reconnect your scale.

For other makers see:

    udevadm info -a -p  $(udevadm info -q path -n /dev/hidrawN)

These rules imply that you should be in `plugdev` for the scripts to work.

### C version

There is also [a simple reading program](example/usbscale.c) written in C.

To build it and run tests against PHP implementation:

	cd example

	make test

Usage is as simple as it can be:

	./usbscale /dev/hidraw3

Outputs something like

	70.87 g