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General Category => Your projects => Topic started by: modchip11 on June 01, 2014, 01:54:12 AM

Title: repair a small cetrifuge
Post by: modchip11 on June 01, 2014, 01:54:12 AM
hi pcbheaven user

the  centrifuge  use 2 boards ;

*one power board
-based on pic 16c72a
- make the phase control for universal motor
- read the speed by tacho
- oppen door by bobine
- make the brake

* second display board
-based on pic16c57c
- display the speed in two 7 segment
- display running time in two 7 segement
- display the door status by the (a,b,g,f) segement from one desplay ( _ door closed , |_ door oppened)
- read the 8 buttons
     * butto, up and down for time and speed setting   (4 button )
     * button start to start motor
     * button stop to stop motor
     * button LID to open the door
     * button continue fonction ( i donot use it )

the problem that this centrefuge have always the 16f72a vcc and gnd short-circuit
my custemer ask for board repair i try the cpying prog but the two pic's are code protected

So i try the reverse ingeniring
i got the display of speed and the time and the 4 button for setting time and speed    (for the display board )

i got also the motor speed control and i think it is easy to read the speed from tacho

i do all the two board by changing the pic's by the 16f876a

but i m stuck on the way that make the communication for the two board

any one can help they made this connection on the picture
thank s in advance 


Title: Re: repair a small cetrifuge
Post by: cheerio on June 03, 2014, 22:31:29 PM
not sure but it might be a software driven i2c. hook up a logic analyzer and post the output.