ILI9488 MISO Fault Question

Author	Message
DrifterNL Regular Member Joined: 27/09/2018 Location: Netherlands Posts: 58	Posted: 12:43am 18 Oct 2022         phil99 said   Edit. Doh, The light just went on! MMBasic uses 16 bits for LCD screens, not 24 bits. You will never get 255 back for any colour. Your transistor is probably working just fine. Now I remember reading that somewhere also... oops But something isn't adding up so I tried something: I disconnected the SD card MISO line and reconnected the lcd MISO directly to the PicoMite. If this is 16 bit (5-6-5) colour then if I cls 263172 (&b00000100 00000100 00000100) I should read back with pixel value 1024 but I get value 263172 which seems that this is an 18 bit (6-6-6) colour. looks like MMBasic drives the ILI9488 in reduced 262K 18bit (6-6-6) colour mode. I reconnected the sd card reader and built up the transistor circuit again but was still not getting the correct values with 5K1, 10K, 20K, the error just went up. I Then went down in resistance and tried an 2K2 resistor and it worked! Reading and writing from to sd card and Blit works and pixel gives the correct 18 bit colour code I will do some further testing but it looks like the BC557A with a 2K2 resistor works. Edited 2022-10-18 11:01 by DrifterNL