# creating an electronic scale with Linux

I have no skills with electronics, but I can code. Which kind of hardware I can use to create an electronic scale that runs with Linux? Will Arduino fit this task? Where can I find the sensor to keep track of the weight?

In my application I need to keep track every hours of the weight of a liquid bottle and store the results into the hardware until I plug an USB pen drive on the board. I have to detect that and store the data onto the USB pen.

How do I get started with this?

You can begin by looking at this Texas Instrument application note: MSP430F42x Single Chip Weigh Scale or those design note from Analog Devices: Precision Weigh Scale Design Using the AD7192 24-Bit Sigma-Delta ADC with Internal PGA and Weigh Scale Design. This, also, is a block diagram for a weigh scale.

Basically, you use a load cell, an amplifier and an A/D converter, which feeds the data into the microcontroller.

Then, after this is working, you can work on interfacing it with the computer (some models of the MSP430 have USB support on-chip; other microcontrollers might have this feature too).

As for USB host (needed to store data in an USB thumbdrive), you can use (e.g.) the MAX3421E to add support if your microcontroller don't supports this function.

• +1 for a couple of good application note links. I can find MSP430s which have USB device capability on chip, but are there any with USB host capability? The OP wanted to plug in an USB pen drive to the board, as well. – Anindo Ghosh Nov 22 '12 at 21:27
• @AnindoGhosh I don't know; couldn't find anything. – Renan Nov 22 '12 at 21:31

How about: get a scale that communicates via RS-232. Plug it in and use your Linux's corresponding /dev/ttyS<n> device to read it.

• What is this 'g' you speak of? – Vorac Nov 23 '12 at 15:01
• @Vorac Oops, should have been get. Do you still have a problem with this answer? – Kaz Nov 23 '12 at 15:48
• Apparently I am quite dim :(. Great answer for someone, who "I have no skills with electronics" an does not have a couple of years free time after work before project launch . – Vorac Nov 23 '12 at 16:17