1
\$\begingroup\$

Ok, Let me explain: I would like to drive 15 analogs (0-12V) signal from my computer (based on user interactions/other not-so-cool stuff).

This hardware has to be controlled over USB or Serial port or USB-to-serial adapter, keep in mind that this application will be installed on various OSs (I have to control this board from an application I already have, written in c# (for windows) and in java for linux (both with c++ parts))

I've considered using Arduino, there's one version with 15 PWM outputs and it should be possible to do exactly that.

I can "convert" PWM signals to voltage using a mosfet (and that's pretty easy). Each output will require about 200mA.

Does anyone know a similar solution?

\$\endgroup\$
3
  • 1
    \$\begingroup\$ Your question is vague. Please explain your constraints. To get 0-12V, you will need either some sort of interface electronics (e.g. transistors are something more), or a MCU with 12V tolerant pins. To understand which, we'd need to know how much current is required, and what programming languages and platforms you prefer to use. Do you want to communicate with this electronics over USB? \$\endgroup\$
    – gbulmer
    Aug 14, 2014 at 12:29
  • \$\begingroup\$ Over USB or Serial port or USB-to-serial adapter, keep in mind that this application will be installed on various OSs (I have to control this board from an application I already have, written in c# (for windows) and in java for linux (both with c++ parts). < sorry, I am a software developer, not an electrical engineer :) > \$\endgroup\$
    – AndreaCi
    Aug 14, 2014 at 12:35
  • \$\begingroup\$ It might be worth adding that comment to the question. My interpretation is, you are okay using a USB-to-serial interface. That opens up the possibilities! \$\endgroup\$
    – gbulmer
    Aug 14, 2014 at 12:37

1 Answer 1

1
\$\begingroup\$

I would use something cheap and simple, like an Arduino, and an "LED display driver" chip. Then it does not matter how many PWM signals are on the MCU. In fact you could use a tiny MCU, maybe even an 8pin device. The "LED display driver" handles all of that.

Typically they drive LEDs directly, so dispense with any need for external transistors. Many have constant current source drivers, and so dispense with any need for external current-limiting resistors for the LEDs.

Many manufacturers make such chips, for example TI display drivers

Also Maxim Integrated

Many do PWM themselves. The PWM data is loaded over a serial channel (which could be done using SPI or bit banging), and the chip 'just does it'. Many use one external resistor to set the overall current for all of the LEDs.

Some come in DIP packages that you could prototype on a breadboard. Some cost under $2.

They can also be 'stacked' end-to-end, so if you need to add more PWM outputs, you'd just add another part.

If you wanted to strip out the MCU completely, you could get a USB-to-SPI chip. I think it is more awkward than using an MCU, e.g. an Arduino, but YMMV.

\$\endgroup\$
3
  • \$\begingroup\$ MAX7219 for example. There are also dedicated PWM modules. \$\endgroup\$
    – sherrellbc
    Aug 14, 2014 at 13:59
  • \$\begingroup\$ @sherrellbc - Thanks. I added a link to what looks like the whole range of products to complement your datasheet link. \$\endgroup\$
    – gbulmer
    Aug 14, 2014 at 14:18
  • \$\begingroup\$ I would like to chip the TLC5940 in since it does hardware PWM and has an arduino library for it already \$\endgroup\$
    – Funkyguy
    Aug 14, 2014 at 14:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.