FSMC Progress

A project log for Lerdge 3d Printer Mainboard Hacking

Breaking the encryption on the Lerdge series mainboards so I can try porting Marlin 2.0 to it.

J.C. NelsonJ.C. Nelson 07/08/2019 at 05:000 Comments

A week ago, my STM32F4xx mcudev black board arrived, with a fun STM32F4 processor on it and a TFT LCD interface. I also ordered the cheapest LCD I could find on AliExpress, an Orise clone that specifically mentioned supporting FSMC access. The pinout wasn't identical to what the STM32F4XX wanted, but with a nest of jumper wires, I hooked them up to the right ports.


I want to build a nice, generic FSMC library where I can tell it the configuration and let it do the rest, and FSMC code is very picky. I found a sample for Keil MDK (which is very expensive) and slowly began cutting it over from the Standard Peripheral Library to the ST HAL. Finally, I managed to get some code that successfully initialize the LCD, but the Orise is an oddity - it can be hard reset from software. The reset pin isn't even used during init. Most LCDs require a reset sequence (lerdge certainly does).

The other advantage of this hardware is that it has an XPT2064 resistive touch, just like the lerdge, meaning that next I can hook the four wires (SPI + Interrupt) for the touch, and get that working. 

Lastly, SDIO + DMA will be the end goal, with DMA from an aligned buffer. Touch work will come first.