Need Help for a product status identification idea

Thread Starter

AMEHDI

Joined Jul 8, 2019
2
Hi All,

I work in a sales role, and I have an idea to implement a "product status identification" system. Basically, I want an LED indicator to be placed next to the products, and be linked to our database, and signal when the product stock is running low. So when stock is above say 10 pcs, it will be indicating green, at 5 pcs, yellow and at 2 or less, red.

The database is linked to the cash registers so it is constantly updating as products are purchased and returned.

I am wondering if this is possible, and what are the components required to launch this idea? I need some guidance towards the right reading material, and any other input is of course welcomed.

Regards
A. Mehdi
 

dl324

Joined Mar 30, 2015
8,877
Welcome to AAC!

Having indicators for each product will be a pain if product is relocated, dropped from stock, newly added, ...

If it's for restocking purposes, that should be done using the database; not going around looking for LEDs indicating low stock. I suspect your store determines stock levels using a number of parameters (lead time, purchase history, etc).
 

Thread Starter

AMEHDI

Joined Jul 8, 2019
2
Hi Dennis,

Thank you for your response, it is a very valid comment! I am wondering if it would be possible to have the LED indicator linked to the product identification number. So, if a product is indeed changed, or a new product is added in its place, we change the location identifier in the code itself. We basically have a bay layout system where we have a plan view of the bays and the products laid out on it, with each product given a number (usually between 1-30 per bay).

It is not only for restocking purpose, but to also allow customers to identify quickly if the product is simply out of stock in the store instead of spending their time looking for it in the overheads.

The main thing that I am trying to figure out is how to link a database to the LED. I am not an electronics engineer, however I studied logic gates back in school. I have a feeling that I will end up using logic gates somehow, but I only know how to create a physical logic gate (with a couple of transistors, a resistor and switches.. ). How do I get a circuit to recognise information in a database?

I understand my questions may be worded weirdly, but I hope that you can make sense of it.

Regards
A. Mehdi
 

AnalogKid

Joined Aug 1, 2013
8,102
What system is the database running on? Operating system name and version, database engine name and version, etc? Over how large an area are the products spread out? AND, how many different products to track? The logistics of the problem could be much harder than the programming.

ak
 

dl324

Joined Mar 30, 2015
8,877
It is not only for restocking purpose, but to also allow customers to identify quickly if the product is simply out of stock in the store instead of spending their time looking for it in the overheads.
When I want to purchase more stock than a store has on display, I'll ask a sales associate. Some stores have additional stock in the area where the product is displayed, but more keep it in some storage area.
The main thing that I am trying to figure out is how to link a database to the LED. I am not an electronics engineer, however I studied logic gates back in school. I have a feeling that I will end up using logic gates somehow, but I only know how to create a physical logic gate (with a couple of transistors, a resistor and switches.. ). How do I get a circuit to recognise information in a database?
You're not going to want to design with gates to access a database. It can be done, but the circuit won't be small.

You can put the intelligence at the point where the indicators are or you can have a centralized controller that operates remote indicators. Either way, the amount of wiring and/or hardware won't be insignificant if you're talking about a large number of items.
 
The biggest problem would accessing the database. If National Instrument's LabView (Visual programming language)can access the database, then that's a start. This would use, say a PC to get the data.

This https://lmgtfy.com/?q=plc+database+access search should give you another idea. This would use a PLC to get the data.

That is about 75 digital outputs if you used an RGB LED such as https://www.amazon.com/EDGELEC-Tri-color-Multicolor-Resistors-Included/dp/B077X95LRZ RED and GRN turned on at the same time would give you some varient of yellow.

The PLC generally operates on 24 VDC and would have it's own digital output ports.

MODBUS is yet another way of controlling stuff. Many PLC's will support MODBUS. the protocal runs on RS485 and Ethernet. A MODBUS segment supports 32 devices. one is a master.

I'll throw this http://www.sealevel.com/product-category/functionality/remote-io/ out too.

I'll throw this https://www.microdaq.com/catalogsearch/result/?q=digital+I/O out as well. These are mostly USB, s you may need an ethernet to USB serial server if you went the LabVIEW route.

Going the RGB LED route may or may not give you problems. I'd choose a resistor that would make each color appear approximately the same intensity to the eye. You'd have to get that art working too.

Generally, we don;t like lots of wires. So, look at addressable LED drivers. e.g. https://core-electronics.com.au/tutorials/addressable-rgb-led-controllers.html

The ADAM-6256 module is expensive. Google that one.

it's a lot of wires spread out to do it the stupid way.

The beginning and endpoints are both difficult.

There may even be another approach where you would multiplex, say a group of 8 LED's with say an Arduino. That would give you control of the intensity. Maybe there is a MODBUS library available.

Brightness and the size of the LED would have to be worked out.

So, the arduinos say would control 8-10 multiplexed RGB LED's and would be a MODBUS SLAVE using RS485 or Ethernet.

The SIEMENS LOGO might be able to handle a FEW LEDS (8-10), but it might not be fast enough for multiplexing.

3 separate LEDs might be easier. You can latch them and set the intensity colors with fixed resistors. Might be able to make a small PCB that would latch the LEDs and then daisy chain to the next one. e.g. 3 outputs, one for each color, 4 outputs (binary) for 16 LEDS , 8 outputs for 255 LEDs. You might need a few other signals too, like an input saying the interface is ready.

So, what, you change one at a time. Less ports, less wiring. Say a daisy-chained ribbon cable and power. You could put a uP there too and maybe do the single LED thing.
Then another that would be used as a strobe. 000 might be considered off.

These are some ideas.
 

Yaakov

Joined Jan 27, 2019
1,536
This shouldn't be very difficult using any of several IoT WiFi connected boards readily available on the market. They are small, low powered and easily interfaced.

The question is budget—how much can you spend on each one?

I would look at something like the Particle ecosystem (https://www.particle.io) if you can afford it, or ESP 8266 (https://www.esp8266.com) boards if you have to go dirt cheap.

The are retail systems that use LCD price tags that dynamically adjust prices, this would be much simpler. It's really not a very hard problem if the budget is sufficient.
 

Yaakov

Joined Jan 27, 2019
1,536
They are actually e-paper displays. e.g. https://www.aliexpress.com/i/32929629021.html
The ones I am thinking of are LCDs, same idea though. The ePaper makes sense from a power consumption angle.

These are just little boxes, about 6cm*3cm*2cm with an LCD. I haven't looked into the guts of them, but they can change prices dynamically. I'm not certain how they communicate. It could be something near-field and a person scans them, or something.

The solution I am proposing would use WiFi. Not a hard project given enough money and time.
 
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