P10 LED Running Text Controller Project

[alvin_nt]

Hi,

I'm currently building a small project for displaying some data on a running text. The running text is using 2xP10 module, that is going to be powered using a board connected via Wi-Fi (802.11). The running text should be as 'dumb' as possible, i.e. it can only display a single, formatted floating number, with a percentage embedded at the back. After I've done some research, these are my findings:

• I can't use the ready-made Chinese microcontrollers, since their protocol(s) is not open (CMIIW). The users would be able to type anything using the supplied software.
• An ATMega-based board (i.e. Arduino) or SoC like ESP8266 are possible candidates to implement the logic for driving the running text
• The embedded DC power supply (was bought along with the ready-made Running Text) is operating at 5V. Therefore, if an ATmega is used, a boost converter is necessary to make sure that it can be powered using the same power supply. OTOH, a buck converter would be necessary to step down the voltage, if an ESP8266 module is going to be used.

Since there are several of these running texts (6 of them), keeping the cost low would be a nice option.

Moreover, this is a project for a company and the company does not own proper equipments for building stuff, such as an oscilloscope, a logic analyzer, a good multitester, helping hand for holding PCB, a good wire stripper, etc. These will need to be procured first (if my manager decides that building a custom hardware is worth the buck, this is not an electronics company FYI).

There are three questions:
- Since the ESP8266 module is operating at 3.3V, and the P10 is operating at 5V, I think OpAmps (like the LM741) can be used to boost the 3.3V output from GPIO/SPI. I have no info on the power supply, but guessing from the build, I think it is rated at 5V, 10A (the cheap, switching ones). Is it possible to use the same power supply to supply power to the OpAmps (I think 5-6 are required, plus one microcontroller)? Last time I measured, the power supply is operating around 5.1V.
- Is a budget around $800 is enough to procure the hardware needed? I live in Indonesia, so access to Ebay would be close to none. There are some places that I can procure the stuff from.
- The power supply (rather new, was bought at February this year) is emitting 'clicking' sound when it is turning off (the AC supply is disconnected). Whenever it 'clicks', the microcontroller 'blinks'. Is this a normal behavior, or a signal of bad power supply? Any way to diagnose this? What about rectifying it (I was thinking of connecting some capacitors in parallel, so that the microcontroller does not oscillate between turning off or on)?

FYI, I have some background in making software (I have a degree in CS, have done an internship before, made some apps here and there). I know more about software than hardware (did a course on Fundamentals of Electric Circuits, learned basics of Op-Amps to Phasors, but that was years ago).

Thanks for reading!

[danadak]

- Since the ESP8266 module is operating at 3.3V, and the P10 is operating at 5V, I think OpAmps (like the LM741) can be used to boost the 3.3V output from GPIO/SPI. I have no info on the power supply, but guessing from the build, I think it is rated at 5V, 10A (the cheap, switching ones). Is it possible to use the same power supply to supply power to the OpAmps (I think 5-6 are required, plus one microcontroller)? Last time I measured, the power supply is operating around 5.1V.

Use level translators easiest.


http://www.ti.com/lit/ml/scyb018h/scyb018h.pdf

http://www.onsemi.com/PowerSolutions/parametrics.do?id=649

- Is a budget around $800 is enough to procure the hardware needed? I live in Indonesia, so access to Ebay would be close to none. There are some places that I can procure the stuff from.

$20 should be your approximate budget. Not including display module.


Can you post a datasheet for the 2pX10 module ? That would help determining your
power requirements and interface.


Regards, Dana.

[alvin_nt]

Hi Dana, thanks for the prompt reply.

The LED module is not called 2PX10, but P10. I'm using two of them, which are connected horizontally using an interface at the back. If I'm not mistaken, some sites mention that it is basically some shift registers wired up together

http://ledworld.ae/resources/uploads/brochure/pdf_1342627000.pdf

- Is a budget around $800 is enough to procure the hardware needed? I live in Indonesia, so access to Ebay would be close to none. There are some places that I can procure the stuff from.

$20 should be your approximate budget. Not including display module.

By hardware, I mean both the tools and the components required. The components should be rather cheap ($20?), but the tools (multimeter, tweezers, helping hand, drill, etc.) also need to be bought.