all led lights and mios don't load

Testing/Troubleshooting
1

bonjour,

I’ll try to write in english.

I read tongenerator pb and it looks like mine.

My midibox :

core

dout with two interrupts

din with 64 leds

I tried dout_button test and , when i start midibox, mios don’t load and all leds are lights.

When i try the same with only one dout x4 and the first shift register on it, the test works fine ( one led lights sequentially with one interrupt).

I must to say i have wired badly the dout the first time and i wondered if i had not burn the shifts registers ( especially sclk and rclk because they “taked 5V on the teeth” the first time  :-[).

2

Sclk and Rclk INTO a DOUT board should be fairly robust.

By this I mean they are meant to take signals up to around 5V as part of their operation, so feeding them a constant 5v is not so bad.

However, if you have shorted sclk and rclk to 5V, you could damage the PIC, by holding a driven pin to a voltage level. I’d imagine the PIC has a certain amount of protection against this… Anyway, if you had damaged the PIC, then sclk and rclk would not work, and no dins or douts would work as a result.

Try one DOUT board at a time (as you have). The next step is finding out which board is bad, (the one which makes it stop working), and figure out what is wrong with this board.

EDIT: Formatting…

3

Tilted 1 – Cimo = 0  >:(

dout with two interrupts

din with 64 leds

this is incorrect, just a typo?

I must to say i have wired badly the dout the first time and i wondered if i had not burn the shifts registers ( especially sclk and rclk because they “taked 5V on the teeth” the first time  Embarrassed).

that should n t be  a problem, but i ve destroyed some 74165s just with static

I tried dout_button test and , when i start midibox, mios don’t load and all leds are lights.

When i try the same with only one dout x4 and the first shift register on it, the test works fine ( one led lights sequentially with one interrupt).

Can you try to swapt the 2 SRs on both the placements? In this way you can bu sure if they are ok or not

Simone

4

hello,

i am so confuse .

two interrupts in din and 64 leds dout.

I tried to swapt all of the SR’s but it works with only the first alone.

5

Did you swap:

Just the SR chips

The SR chips and the boards they are in

The SR chips and the boards they are in and the cables connected to that board

Try them all :wink:

And remember - each test should be the result of ONE change. Be methodical, and record all of your results.

6

hello,

i have read something like that in midio128 page :

" It’s only important that the last input shift register is terminated with ground level (0V), so that the firmware doesn’t recognize invalid values."

there  something with my probleme and somebody could explain what does it mean. Is the last input  SER or O8 ?

How to put that on ground ?

7

" It’s only important that the last input shift register is terminated with ground level (0V), so that the firmware doesn’t recognize invalid values."

there  something with my probleme and somebody could explain what does it mean. Is the last input  SER or O8 ?

How to put that on ground ?

I guess that’s a small documentation error and TK is talking about the SR chain pullups. These are R33-R36 in the DIN schematic (http://www.ucapps.de/mbhp/mbhp_dinx4.pdf). They make sure that the chain input of the last 165 chip (SER) isn’t floating, i.e. doesn’t detect random input events when no other 165 is feeding that input. If you put GND to that last SER input, it would make the box send note ons for the rest of the (nonexistant) chain, so it should read “It’s only important that the last input shift register is terminated with a 10k pull up resistor to VCC on its SER input, so that the firmware doesn’t recognize invalid values.”