communicartion with a digital scale

Projects General Guidance
1

I need to serial communicate with a digital weighing scale or balance, RS232 or USB. The two manuals I have read describe communication exchanges with ascii strings that are kind of the same but enough different to be a pain.

No doubt I can make it work but I hate to work toward a dead end with regard to the application or extension of the code I develop. Does any one have some practical advice about the way scales communicate and which ones to seek out or avoid? Does anyone have some existing code to share? I would be pleased to contribute to something that already exists rather than reinvent a wheel.

2

Does any one have some practical advice about the way scales communicate and which ones to seek out or avoid? Does anyone have some existing code to share? I would be pleased to contribute to something that already exists rather than reinvent a wheel.

Other then using USB or serial communications standards, I would be pretty sure that every manufacture of such scales would use a different and proprietary protocol for their scales. Heck, I wouldn't be surprised if there was not significant differences between models from the same manufacture. So best you can do is to link to the proper manufacturers manual and see if anyone can help you with building your sketch to support it.

Lefty

3

Research the kinds of scales used in 'point of sale' applications. If you are lucky there may a de facto interface standard that manufacturers adhere to.

4

I need to serial communicate with a digital weighing scale or balance

Which one?

The two manuals I have read describe communication exchanges with ascii strings

Which manuals would they be?

Are you looking for a scale you can communicate with, or are you looking to develop (or reuse) code that communicate with ANY scale?

5

mjbmikeb thanks for the sanity check.

You are correct, there must be some common denominator. Guess I will just buy a pretty one and live with it. I will know a lot more in a week or so.

Nothing inspired is necessary, just slave labor to create the command strings and to dig the needed values out of the ascii response strings, make it work and keep the execution from overwhelming really tight ram. The needs are pretty minimal, so really specific code will probably come from this, not a general solution. Thanks again

jac

6

If its USB, then you may have issues - it will likely be expecting to talk to a USB host, and arduino is not.
If RS232, then you can add RS232 to TTL adapter and bring the signals in on D0/D1 Rx/Tx and talk to it more directly.