Hi everybody I finished my mbfm + built-in 4-channel stereo mixer + tone control. I built it around a heathkit ET-3200 case. The mixer has balance, volume, phone amp and RCA connectors. I used a dvd player power supply (+5/+12/-12) and works fine. Here some pictures.
But I have a problem: with a 18F452 the LCD works fine, but when I use a 4685 it gets stuck after pressing/rotating a little bit here and there (but the rest still working, it plays notes and I can change parameters …). I looked around and realize that 4865 works in 4-bit mode with the LCD, but still the problem after fixed that. I thought in a corrupted midi transfer but the 452 works fine. What can be the problem? Thank in advance for your comments.
first I wired up the 8, then only 4 and D0-D3 from the LCD to ground and D0-03 from CORE open. The strange thing is it doesn’t get stuck when I move the data dial, but when I use the selection matrix or the v-pots it gets stuck after 3 seconds … I don’t understand why, please any help? Thank you for your reply.
first I wired up the 8, then only 4 and D0-D3 from the LCD to ground and D0-03 from CORE open. The strange thing is it doesn’t get stuck when I move the data dial, but when I use the selection matrix or the v-pots it gets stuck after 3 seconds … I don’t understand why, please any help? Thank you for your reply.
If a PIC18F4685 is used in the project (-> MIDIbox SID V2), the LCD is accessed in 4bit mode. Accordingly, the data pins D0/D1/D2 and D3 should be left open at core and LCD side (don’t connect them to ground!) - see mbhp_lcd_4bit_mios8.pdf
If a PIC18F4685 is used in the project (-> MIDIbox SID V2), the LCD is accessed in 4bit mode. Accordingly, the data pins D0/D1/D2 and D3 should be left open at core and LCD side (don’t connect them to ground!) - see mbhp_lcd_4bit_mios8.pdf
Yes I set the connectios like that but the problem persist. Then looking in the wiki I found this:
;; using the 4-bit interface:
;; -> connect MBHP_CORE:J15:D7-D4 of the core module to D7-D4 of the LCD
;; -> left MBHP_CORE:J15:D3-D0 of the core module open!
;; -> tie D3-D0 of the LCD to ground
So I tried it (D3-D0 of the LCD to ground and D3-D0 of CORE open), but again the problem persist, I don’t know what else to try.
I think I found the problem. I’m using a dvd player switching power supply and its +5 Volts varies between 5.25 and 5.4 Volts. I tried with 5.0 volts coming from an adjustable power supply and the LCD works fine, never got stuck.
May be is the PIC or the LCD that have problems with voltages around to its limit (5.5 Volts).
