I’ve committed (and pushed) an experimental extension to allow C++ objects to be optionally moved to SPI RAM. The code is in ovms.h, so should be easily accessible to everything. It is pretty simple: We have a new class ‘ExternalRamAllocated’. That does nothing except override the new and new[] operators. Those operators try to malloc from SPI RAM first. If that doesn’t succeed then they fall back to standard internal RAM. The definition of a C++ class can then be changed to make it “: public ExternalRamAllocated”. Once that is done, any objects of that class allocated will try to be placed in external (SPI) RAM. For other malloc uses, a general purpose 'void* ExternalRamMalloc(std::size_t sz)’ function is also provided. To test this, I’ve made a one line change to the OvmsCommand class: -class OvmsCommand +class OvmsCommand : public ExternalRamAllocated Here is what the memory usage looks like: With SPI RAM disabled (in menuconfig): Free 8-bit 120844/284304, 32-bit 30508/57680, SPIRAM 0/0 --Task-- Total DRAM D/IRAM IRAM SPIRAM +/- DRAM D/IRAM IRAM SPIRAM no task 5312 0 0 0 +5312 +0 +0 +0 esp_timer 52328 0 644 0 +52328 +0 +644 +0 main 16448 0 0 0 +16448 +0 +0 +0 ipc0 11096 0 0 0 +11096 +0 +0 +0 Housekeeping 40576 5120 0 0 +40576 +5120 +0 +0 tiT 128 0 0 0 +128 +0 +0 +0 Tmr Svc 884 6444 0 0 +884 +6444 +0 +0 ipc1 12 0 0 0 +12 +0 +0 +0 AsyncConsole 20 0 26404 0 +20 +0 +26404 +0 Without deriving OvmsCommand from ExternalRamAllocated: Free 8-bit 119240/282436, 32-bit 424/27596, SPIRAM 4193924/4194252 --Task-- Total DRAM D/IRAM IRAM SPIRAM +/- DRAM D/IRAM IRAM SPIRAM tiT 0 0 0 128 +0 +0 +0 +128 Housekeeping 40564 5120 0 12 +40564 +5120 +0 +12 no task 5348 0 0 0 +5348 +0 +0 +0 esp_timer 52328 0 644 0 +52328 +0 +644 +0 main 16448 0 0 0 +16448 +0 +0 +0 ipc0 11096 0 0 0 +11096 +0 +0 +0 ipc1 12 0 0 0 +12 +0 +0 +0 Tmr Svc 884 6444 0 0 +884 +6444 +0 +0 AsyncConsole 20 0 26404 0 +20 +0 +26404 +0 After deriving OvmsCommand from ExternalRamAllocated: OVMS > module memory Free 8-bit 152308/282432, 32-bit 424/27596, SPIRAM 4160852/4194252 --Task-- Total DRAM D/IRAM IRAM SPIRAM +/- DRAM D/IRAM IRAM SPIRAM esp_timer 31664 0 644 20664 +31664 +0 +644 +20664 tiT 0 0 0 128 +0 +0 +0 +128 Housekeeping 39636 0 0 6060 +39636 +0 +0 +6060 no task 5348 0 0 0 +5348 +0 +0 +0 main 16448 0 0 0 +16448 +0 +0 +0 ipc0 11096 0 0 0 +11096 +0 +0 +0 ipc1 12 0 0 0 +12 +0 +0 +0 Tmr Svc 7328 0 0 0 +7328 +0 +0 +0 AsyncConsole 20 0 26404 0 +20 +0 +26404 +0 The advantage of SPI RAM is obvious. 30KB of internal RAM saved with just one line changed in a header file. Most of our other objects like that (metrics, configs, etc) could be equally easily moved to SPI RAM. We can make the decision on a class-by-class basis. I think this is a pretty good solution. It puts the onus of the decision of whether to put into SPI RAM into the object itself (as presumably the object knows best whether it can actually be put in SPI RAM). It is also extremely simple to define that. But, it is an experiment. Please let me know what you think. Regards, Mark.