I measured the 1st and 2nd point, I'm not very familiar with my ammeter, so I didn't do the 3rd point (if it is important, will also do it)

as we guessed, one of the points is GND, the normal current of points is 4,85v and once I pressed the button, it droped to Zero. I did it many times and on both points and the result was same whole time.

 

I
as we guessed, one of the points is GND, the normal current of points is 4,85v and once I pressed the button, it droped to Zero. I did it many times and on both points and the result was same whole time.

I take it that this is +4.85V?

 

This was my initial Problem which triggered to ask this question. I have a AOYUE 968 Reflow Station which I want to use to lift up BGA Chips.
Doing it, needs to keep a Profile from various Temperature and with an exact time length e.g.
183 oC -> 2 min.
231 oC -> 2 min.
271 oC -> 10 sec.
and so on.

as you see on picture, there are 2 buttons for increasing or decreasing the temperature and 2 Displays, the above one shows the set temp and the below one shows the current temp.

if I connect 2 points on PCB behind the display with a screwdriver, the temperature will be increased or decreased (depend on which button I connect)

so my Idea was to build a very simple circuit with relays to control the pressing the buttons by a PC.

After re-reading this I just realized that the code that I posted needs to be edited because you will not want both switches closed simultaneously... or do you?? I can edit it for you or you can do your own thing, if you wish.

Attached is an Opto-Isolator circuit that should switch those two points to ground. No power is needed and it provides a high degree of isolation between the PC and your Reflow station.

If you want to be able to import the temp data, to display and save to a log file, we are going to need much more information about the Reflow station.

Edit: You may want to open the attachment in a new tab. Sometimes when I open them in a new window some of the circuit is lost. Dunno why though!

 

Thank you very much.

just a question, you indicated 3 Points with GND Sign, can I connect them to DB9-5 or better to use a GND on Board.

I have tried to find connections between front panel and the board and marked them in this picture.

the Chip there (not sure if it is a AVR or PIC) receives the signals from both buttons and forwards it to upper display.
it also receives the current temperature from that LM35 and forwards it to lower display. (also not sure if it is a LM35 as it can measure the temperature till 150oC and the display shows temps till 450 and above, perhaps there are more than one)

is it possible to read the data from that display wire and transfer them to PC?

Thanks again.

 

Thank you very much.

just a question, you indicated 3 Points with GND Sign, can I connect them to DB9-5 or better to use a GND on Board.

Schematic ground symbols are used to indicate chassis ground or board common. They're used to minimize unnecessary conductors all over your schematic. All three of those symbols indicate the same electrical point but not necessarily the same physical point.

is it possible to read the data from that display wire and transfer them to PC?

If there's a point that you can pick off "Serial Data" then we can interface it to the RXD pin on the PC's Serial Port. I don't see this happening without a schematic. Maybe with an oscilloscope you could plod your way through.

Suggestion: Do a search for all the chips including the readout to find out what they are. If the readout circuit has a (Serial Data In) pin you may be in luck.

 

The large chip with CR1 (crystal) next to it is your microcontroller. The manufacturers web page says it's a Microprocessor but I doubt it... Could be wrong though! .... CYA

 

I brought the Board out and took some pictures. the big Chip is an AT89C52. I have marked all other chips and transistors. hope that is what you need.

 

Did we forget how to Google?

 

I brought the Board out and took some pictures. the big Chip is an AT89C52. I have marked all other chips and transistors. hope that is what you need.

The AT89C52 is a Microcontroller.
http://www.8051projects.info/intro_3.asp
Pin 10= RXD (Serial Data In), Pin 11= TXD (Serial Data Out). Post some info and pix of the readout board.

You're asking a lot here. Don't you think it would be a good idea to breadboard the switching before progressing to the data issue?

 

What do you mean from readout board? is it the board with display and buttons?

I'm really thankful that you help me so much. I know that I'm asking a lot, but my idea was to recognize every option and order all necessary parts at once, as it takes about 1-2 Weeks every time till they arrive.

 

Yes, the readout board.

 

Here you are:

 

Just to let you know that I haven't been ignoring you, just busy with other things. Please trace the path from the uC TXD pin(11) to its next node and path to the display. Is the display LED or LCD? Do you have a scope?

 

I know, many thanks.

I have unfortunatly no oscilloscope but as I see, it is free and unconnected.

 

If the DTX pin isn't connected to anything then the displays are getting their data from multiple uC outputs, probably driven from U3, which is a transistor array. This also means that there may be no serial data to read. The fact that the uC has serial in/out pins doesn't necessarily mean that code was written to those pins. Can you get your hands on a logic probe? The other option would be picking the data off of each of the display lines and converting it to serial data..Ugh!

 

I just had a thought. Not a great thought but a thought none the less...Do you have a Piezo element in your box of junk?

 

not so directly, but I think there must be some in one of the playing toys. will check it. otherwise I will build or buy a logic probe. I'm also thinking on building a simple usb scope, if that helps.

 

Yes, I've found a Piezo element. what shall do now?

 

not so directly, but I think there must be some in one of the playing toys. will check it. otherwise I will build or buy a logic probe. I'm also thinking on building a simple usb scope, if that helps.

Great idea, especially if you intend to broaden your electronics experience.

 

Yes, I've found a Piezo element. what shall do now?

Are you sure that it's just the element and not a Piezo Buzzer? The latter is connected to a DC source and it generates a tone.