Hello, in the past two days I've been trying to get working STM32L053R8T6 on my board. I managed to isolate the error down to one setting in LCD module. When using static duty the MX_LCD_Init() init function passes and program executes like usual. But when I try to use all four COMS the CPU resets and in case of debugging it crashes/disconnects the probe. The moment it happens is when reenabling the LCD (in order to write into LCD CR register it has to be disabled) after setting any non static duty.
It doesn't matter if I toggle the bit in STM32CubeIDE through ST LINK or in regular program execution. I checked all LCD pins by bitbanging GPIO outputs, which works, but I can't use multiplexed LCD like that, not to mention the current consumption would be too high.
You should be able to reproduce this bug by enabling LCD module, checking any SEG output, and choosing 1/4 Duty Cycle, then 1/3 BIAS. I also use Debug Serial Wire and external Vlcd power but all other settings doesn't make any difference.
When debuging with static duty I also found that the Multiplex option seems to be inverted and the configuration windows doesn't let me select the SEG28-SEG31 pins but they in fact work and are accessed normally when multiplex is disabled manually in user code.
Can you confirm this part has unusable LCD module for 1/4 Duty and suggest what parts are available as replacement?
Thanks,
Jan
