My current repair job has > 12 PICs

[kolbep]

Yep, you heard me.
I am busy working on repairing a Moving Head stage wash fitting (oby600 wash).
Finally got the schematic, and this thing has a pic micro for almost every motor. WIth two data busses linking everything.

it also had a pic for the 7seg displays and buttons, and another one that looks like the brains of it.

At least I have gotten a break, in that this thing uses a linear powersupply, not switchmode.

But I have to dissasemble most of tge fitting just to check the psu caps.

The fault, if anybody is interested, is that you can send a dmx signal for it to go to position, and it will keep on jerking until it ges there. Sometimes it does not even try to move.
Other motors are jittering the whole time, and the colour wheel keeps on rotating.

Even the builtin demo mode is not working right, so it is not dmx problem

Guess I am going to check the caps, then the interconnects, then the oscillator that is global fforall the micros.

Unldss, on the odd chance somebody has experienced the same problems on a geni oby fitting?

But, over 12 pics. Wow

[houdini]

From the title i was expecting pictures.

[BravoV]

From the title i was expecting pictures.

Same here, and realized PIC as mcu, not picture.

[Fsck]

From the title i was expecting pictures.

Same here, and realized PIC as mcu, not picture.

we've all been scammed. though, a pic of 12 PICs would be amusing to see how they're used.

[dr_p]

[kolbep]

Will post pics of the pics later on.
Each section is almost similar, a pic monitoring a hall sensor, some also monitor optical encoders, then has some other logic glue, and then runs a stepper driver.

[David_AVD]

A lot of faults in moving head are caused by intermittent wiring harnesses (stretched or crushed).  A broken harness can cause missed steps (jerkiness), loss of feedback (continuous "searching", etc.

Of course you must check the power supply rails as excessive ripple or low voltage can wreak havoc in the strangest ways.

[nitro2k01]

Speaking of multiple PICs, remember Dave's Absopulse VFC500 Variable Frequency Converter teardown?

(From around 34:35)

[SeanB]

I must upload a pic of a board from a lotto machine. Has a 68000, a 68HC11, a Z80 clone and another 6800 series IC AFAIK as processors, a lot for a board that just could use one. One does the keyboard, one does the display, one drives the printer via another processor on the printer board and the others do whatever.

[kolbep]

Thanks for the hint on the Harness. I will check it out.
Here are some pics of the pics. There are some more that are hidden by the metalwork at the bottom of the yolk for the head.

[amyk]

I remember mikeselectricstuff mentioning one of his installations used a lot of PICs...

[mikeselectricstuff]

I remember mikeselectricstuff mentioning one of his installations used a lot of PICs...

For various reasons, this has one PIC10F322 per LED, about 2600 of them in total!
http://www.uva.co.uk/work/continuum

[free_electron]

I remember mikeselectricstuff mentioning one of his installations used a lot of PICs...

For various reasons, this has one PIC10F322 per LED, about 2600 of them in total!
http://www.uva.co.uk/work/continuum

so you made connection machine ... 

http://www.mission-base.com/tamiko/cm/

that hing had thousands of 1 bit cpu's. 2 bits in 1 bit out. every output had an led attached. the cpu's commniceted in a hypercube configuration

[amyk]

Now try to find even one product that has > 12 AVRs...

[hemmikall]

my guess would be failing motor drivers, for the color wheel My guess would be that an optical encoder has failed, if it uses a hall effect sensor make sure that the magnet is still on the color wheel.
the jittering may be caused by the fixture not exiting calibration mode (startup) due to failed motordrivers or sensors and that might explain why it won't go into the demo mode, in many fixtures you can access the menu while it's still in startup/recal mode but it doesn't do anything until the fixture has found home position for every function

one good way to test if motor drivers are good or not is to push the head around (manually move pan and tilt) if it has almost no resistance (really easy to turn) it may be either the motordriver or the power to it