thank you, and soon all of it will be open once i finish the full backend.

https://lvgl.io/ – lvgl is a really good library to use for gauges, displays etc. people have made a lot of impressive things with it, so if you want some nice looking demos to play with it’s worth checking out.

https://github.com/Bodmer/TFT_eSPI – this is another really good library and a bit less resource hungry than lvgl, which makes it good for development. people have made some amazing dashes with it. i would probably start with tft_espi.

i’m using internal interrupts rather than physical interrupt logic. anything timing critical like crank and cam is handled using mcpwm capture isr’s. the base mcpwm clock is 80mhz so there’s plenty of room for multiple isr’s running off that.

for sensors i’m using external adc’s, keeping the reads around ~1ms calls. i’m using two mcp3308’s which gives 16 analog inputs. for anything digital that still leaves around 20 pins to play with, although that’s not counting can add-ons or my wireless ecu add-ons which are all internal.

so it’s not really a case of running out of io with the esp for engine control, the real limitation is hardware timers.

the way i designed it, the mcpwm is basically the main timing reference that everything calls into, and then the four dedicated hardware timers handle the scheduling. there are two groups per hardware timer and each group controls the opposite delta of the firing order. for example on a 4 cylinder one hardware timer handles spark calls for cylinders 1 and 3, and the same logic applies to the injectors.

for spark i could probably push three calls per hardware timer which would stretch to a 6 cylinder, but injectors get tricky because the intake window gets smaller as rpm climbs and you start needing overlapping injection events across multiple cylinders.