PCI or USB GPIO Expansion Devices for PC-Based Embedded Peripheral Testing

Folks,
I am new to this and don't know what I am doing. I come from a "big machine" software environment where testing things in isolation before integration is a best practice. I am getting into embedded as a hobbyist and I am finding the concept of coding straight onto the MCU in order to get additional components going (WiFi, LCD display, etc) a little bit less efficient than it might be.

I wonder, since my "real PC" is multiple times faster than the MCU I am coding against, is there any hardware such as PCI card (or eek, USB 3.0 perhaps) device which can give me a bunch of GPIO pins? This would allow me to connect the peripherals to that, get them working on the PC and once I got the code/protocols/etc down right, I could recode or "port" the code over the MCU for final integration?

I am happy to clarify what I am thinking at, but thought perhaps there is something out there or a good reason why there might not be.

Thanks for all the advice,

Hanan

Sounds like what you're looking for is ICE (In Circuit Emulation). This is a hardware device that behaves like the target MCU but removes the tedious Build/Write/Test cycle. And, you can not only go directly to Test, you can do some serious debugging, too. Because you are working directly withing the "MCU Space", you have direct access to ALL of the functionality, from inside the [pseudo] MCU.

Just Google "ICE ".

The Forum software filtered out one of the terms in my suggested Google search phrase (probably because I used angle brackets and it thought I was trying to embed HTML [and because there is no Preview, I wasn't able to catch this before going live ;] So here it is again with different punctuation:

Just Google: "{your preferred MCU technology, here} ICE"


[ test: < angle brace alternative? > ]

OK... notice my little "test" in my last Reply? What I did was use HTML codes for the '<' and '>' like this:

&lt; for <
&gt; for >

BTW: I used &amp; for the &

As Steve mentioned, you could use an emulator. Most of these are simple USB interfaces to the JTAG / Spy-by-wire interface of the system micro. Using this you can pause the execution of the debugging, and flip individual GPIO bits while paused to test any peripherals that are connected.

Alternatively, if the project is fairly simple, it is sometimes easier just to code smaller portions of the project and validate them one by one. You can easily set up a micro to run a simple function that toggles LEDs, PWMs, serial interfaces, etc. and by writing debug info into the code it makes it easier to troubleshoot. With the JTAG interface / debug, you can set variable watches and check them during execution, etc.

Yeah, thanks for the efforts. I guess this site has somewhat over-simplified XSS prevention running, preventing special characters.

I am going to reply to the bottom of the thread to address both replies, clarifying what I had in mind.

Thanks for your replies, Steve and Scott. I appreciate the pointers.

Scott: I am aware of the JTAG approach, but actually I am thinking of ANOTHER approach, which might be totally wrong/impractical. I am not trying to work with MCU. (see below)

Steve: I was not aware of techniques utilizing ICE, but now I am. But that's not quite what I am getting at. I am not interested in emulating the MCU.

What I want to is to just connect to PC and test components (LCD, Wifi, motors, buzzer, sensors, etc) on an individual basis before even integrating them physically or with code-wise with the MCU. I want to test these components, limits for, say, calibration with real-world inputs, etc., test a motor for control precision with a physical load that it will encounter in a complete system, etc.,

So what I was thinking is, if I had for example, a PCI board with all the wires hanging out connected to the PC (with some overvoltage protection etc), combined perhaps with a rich enough GPIO driver (such as GPIO supported in linux, etc), I could drive these external components, get the kinks out of their behaviour, etc., by just flipping the lines (high/low/clocking data out, etc) on the PCI, reading values, etc. Then when I got those down, I could port my PC-based routines to the MCU for integration. It's a way of UNIT-testing the components before integration. The reason I mention PCI board is because, while there are obviously component-specific (LCD, sensor, etc) testing boards, I am hoping for something generic that I could program on the PC to test anything I wanted.

I could be totally off in my approach and corrections are welcome.


Thanks very much guys,

Hanan