So this may be a soon to be irrelevant question, once 0.4.x goes live for the Core, but it appears that right now, 0.3.4 has a define SPARK in the makefile (this issue), but doesn’t define PLATFORM_ID. However, 0.4.x defines PLATFORM_ID (for use in differentiating Core from Photon from Electron, etc.) but has removed the definition of SPARK in the makefile, so a #ifdef SPARK statement will no longer work. This is somewhat annoying, and is there a better way to deal with it other than this?
@mumblepins, I suspect the SPARK flag will get deprecated in the next Core release. As for the Core/Photon in the 0.4+ versions, there are two aspects to look at - hardware and system platforms. In the new firmware, there are two hardware related flags to differentiate between the STM32F10x of the Core (STM32F10X_MD) and the STM32F2xx of the Photon/Electron (STM32F2XX). These flags should be used to differentiate hardware environments like the Core having 5 hardware timers and the Photon/Electron having 15. Arduino code often differentiates between different processors (atmega168, 328, etc.).
#if defined (STM32F10X_MD)
// Core hardware specific code here
#endif
#if defined (STM32F2XX)
// Photon hardware specific code here
#endif
For system platform differentiation, the PLATFORM_ID flag should be used since there are some differences between the Core and the Photon/Electron. Arduino uses the #if defined (ARDUINO) && (ARDUINO > 100) for example to know which compile environment is being used.
The PLATFORM_ID would be used as follows:
#if (PLATFORM_ID == 0)
// Core code here
#elif (PLATFORM_ID == 6)
// Photon code here
#elif (PLATFORM_ID == ??)
//Electron or other Particle device code here
#endif
No need to test for (PLATFORM_ID) since the above will fail if PLATFORM_ID is not defined to begin with.
Yeah, I'm mainly using it for determining if the flash chip is there (AKA Core but not photon). However, I'm pretty sure that your last #if statement won't work as expected on Arduino or elsewhere where PLATFORM_ID is undefined, as according to this Stackoverflow thread:
From the C Standard:
(C99, 6.10.1p4) "After all replacements due to macro expansion and the defined unary operator have been performed, all remaining identifiers (including those lexically identical to keywords) are replaced with the pp-number 0""
So, if PLATFORM_ID is undefined, the first one will be true. For example, try this, and you'll see the error:
I would like to see a PARTICLE defined so you could test that before PLATFORM_ID since PLATFORM_ID is very generic and has been used for other non-Particle platforms.
What does @mdma think? Is there going to be a direct replacement for SPARK?
Well, perhaps I misunderstood @mdma regarding the compile flag testing! I believe a test is in order! The flag will always be defined in a Particle environment. HOWEVER, if a library is designed to also work on a different platform (eg Arduino) then yes, you are correct to test that way! DOH!
@bko, all of the code I have seen in the library uses either the hardware or platform flags. You’ll have to discuss with @mdma regarding a PARTICLE flag. I had pointed out in the past that I actually came across a library that used PLATFORM_ID for another processor.
For some reason, none of the above code examples work in the Particle Dev IDE. It seems that I might as well write #if (false). Are these defines for the web IDE only?
I haven’t tried that, because I’m not writing portable code right now. What I was trying to get working was the #ifdef to determine whether the code was being compiled for Core or the Photon.
#if PLATFORM_ID == 0
// Core code here
#elif PLATFORM_ID == 6
// Photon code here
#else
#error "*** PLATFORM_ID not supported by this library. PLATFORM should be Core or Photon ***"
#endif
@bdub That works. I don’t understand why it didn’t work when I tried the same code before posting in this thread, but it works now. (P.S. I did upgrade Particle Dev to 0.0.24, the latest version AFAIK.)
EDIT: I understand what I was doing wrong: I need to use #if PLATFORM_ID == 0. Can’t substitute #ifdef PLATFORM_ID == 0. Because, well, it is defined! My bad…and it’s perhaps unfortunate that my socks aren’t chocolate.
@mumblepins, This is a great question but I didn’t find it with the search button. The topic might be more widely helpful if it was retitled Detecting Platform Type (Core/Photon) at Compile Time.
As it stands it only comes up in a search if you know it is there or know the name of the pre-processor flag. @kennethlimcp kindly pointed out the answer when I couldn’t find it.
Hello,
Sorry as I only have a vague understanding of this issue, but I am having trouble using a Neopixel library with my photon redboard, and it is giving me an error concerning my PLATFORM_ID. I was wondering if this thread is dealing with a similar issue and might shed light on how to resolve it.
