SynGuy7

Thanks for info TK. The "good " LCD works in either of J15A/B and shows each screen. I didn't doubt the code, but wondered if the core hardware was a bit erratic. Your test proves it to be ok. I must be just "lucky" in getting 2 broken LCD's. I guess I have to buy yet another LCD then... Thanks

Checked over the core once again. Buzzed out all the connections to the LCD's from the core and 595 chip etc - all ok. Shortened ribbon cables to approx 150mm each. Tried power on several times and suddenly the second LCD started. If I disconnect power I know it will not come on again. Can somebody enlighten me as to how the 2nd LCD is initialized. I assume it is detected somehow by the STM 32 CPU chip and initialized via the boot program from ROM. I am wondering if there may be some fault with my STM 32 chip (it checks out ok when queried via MIOS Studio though). This is very puzzling...any help appreciated. Thanks Dunc

I have checked all I can on this...Grr Yesterday I got both LCD's working all day, today the 2nd one is not initializing again. Nothing has changed in setup etc. Does anyone have a reliable source for the LCD's (originally got 2 LCD's from the German supplier (Mike ?), one of which will not initialize. Bought a new LCD on Ebay which works now and again). I would prefer to get the LCD's in UK (definitely not from the US as the customs charge is a lot). Again, appreciate the replies.

Thanks for the reply. Sorry about not being clear... I have one LCD which works in both junctions 15A and 15B. The other LCD only shows the black boxes across the top row as if it is not being initialized, it shows these black boxes when connected in 15A or 15B (used different ribbon cables to test as well with no change). This morning I received a brand new LCD and it does exactly the same thing. I find it hard to believe that a brand new LCD exhibits the exact same fault as the previous one. I must be missing some crucial setup problem or something. I am a bit lost as to what is happening here. Going away for some days holiday so unable to reply until late next week, but any help appreciated. :smile:

I've built my Version 4 Seq, but have a problem with the 2nd LCD module. No matter what I do it always just displays a top row of 20 black boxes and nothing else. I have swapped it for the 1st LCD and it is still the same. I have also tried another LCD module with the same effect. The MidiSeq seems to be functioning ok otherwise. I figure it is something to do with enablement of the LCD, but as I have tried swapping it to the other junction (15A/15B) and it makes no change to the display I am a bit puzzled as to what is happening here. I can get both LCD screen displays by swapping the "good LCD" between Junction 15A/15B ok. I've read through the construction of the STM32 core construction where it says the 2nd LCD is not initialized by default. I have just uploaded (via USB and Uart Midi) the latest Beta 22 of MidiSeq V4 with no change to LCD after reboot. I have also read the Wiki info about the LCD problem with the black bars but as I have uploaded a correct application is does not seem to apply. Anybody come across this at all ? Thanks in advance for replies.

Thanks for the replies. I did actually zoom in on your photo of construction Wilba, but it was a bit indistinct to see if the track holes had a through connection. Time to get back to construction then. Thanks again. :thumbsup:

I'm currently building the one piece PCB for version 4 and have a number of through PCB holes left (in areas of U5 & 6 and U8 & U2), am I supposed to connect these through the board to the tracks on the backside ? I've looked through the forums and constructions details but cannot find an answer to this. Thanks :thumbsup:

Thanks ultra, that will help enormously. :)

Hi All :), I'm am looking at building a MidiSeq box and have been looking at all the stuff I can find on the site. One question that I cannot seem to find an answer to is what kind of switches are required. As far as I can tell, they need to be single pole, normally open but, I can't seem to find any info saying if they need to latch on. I presume all the switches are to be of the same type ? Thanks in advance