Number of fans limited by firmware?

dc42

@techni these are the current limits for Duet 3 systems:

// Limits of Duet 3 systems
constexpr size_t MaxSensors = 56;						// limited by the size of bitmap we can store in an ExpressionValue
constexpr size_t MaxHeaters = 32;
constexpr size_t MaxMonitorsPerHeater = 3;

constexpr size_t MaxZProbes = 4;
constexpr size_t MaxZProbeProgramBytes = 8;				// maximum number of bytes in a Z probe program

constexpr size_t MaxFans = 16;

constexpr size_t MaxGpOutPorts = 32;					// increased as requested by Jimmykc

// The following currently don't need to be known by expansion boards, but might in future
constexpr size_t MaxGpInPorts = 16;
constexpr size_t MaxSpindles = 2;						// maximum number of configurable spindles

I can increase MaxFans in the next 3.4beta.

TechNi

@dc42 said in Number of fans limited by firmware?:

I can increase MaxFans in the next 3.4beta.

That would be cool! I guess there's a good reason for these limitations but I am sure the Duet can handle this.

@peter247 Neopixels are kinda expensive compared to "normal" LED strips and I'd like to be flexible.

@Phaedrux Did not know you could do that, thanks!

TechNi

@dc42 Hey dc42, I know minor issues like this are not exactly a priority on your list but any chance that this is now fixed in the new RRF 3.4.0 beta 2? I did not find anything in the changelog. Would greatly appreciate this small fix. Thanks!

bot

@techni see if you can follow the build instructions, and modify the value yourself and compile. It shouldn't be too hard.

kb58

If any of these fans are turned on and off at the same time, just wire them in parallel, first checking of course that the driver can handle the total current.

dc42

@techni I will increase the maximum number of fans to 20 in the next beta.

TechNi

@dc42 Morning, was this finally solved in RRF 3.4b3?

dc42

@techni said in Number of fans limited by firmware?:

@dc42 Morning, was this finally solved in RRF 3.4b3?

Yes, I increased the maximum to 20.

TechNi

@dc42 Many thanks!

TimMacey

I have an application that needs 24 fans. Is there a means to do this? I'm running a 6HC MB with 7x 3HC extension boards.

dc42

@timmacey currently (using RRF 3.4) you could only be able to control 20 at once as fans, but you could configure the remaining 4 as GpOut pins and control them using M42. I can increase the maximum number of fans in RRF 3.5.

dc42

@TimMacey the maximum number of fans was increased to 32 in RRF 3.5.