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Topic: Controlling a series of switches of another 5V system from Arduino (Read 1 time) previous topic - next topic


Yes, it should work, and would only take 10 pins from  the arduino rather than the 16 my solution would require...

got to build the hardware, of course...




Everything runs on smoke, let the smoke out, it stops running....


Thank you Allan and Tom!

I have ordered the MT8088 chip now. Long shipment time... but I'll update the thread as soon as I prototype something.


Where'd you order MT8089 from? I didn't see any sources.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


I couldn't either. I ordered MT8088 instead whose specs look very similar.


I ordered MT8088 here:



I see the problem - part number changed from MT8808 to MT8088 with the forum page change.
MT8808 available at both Digikey & Mouser in 28-pin PLCC package. Nearly a $10 part.

You found a DIP part eh? Hope it's a quality part.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


Yes, the link I posted above is for a DIP, and that's what I ordered.

It is a Chinese distributor, I have no idea how reliable they are and what quality this MT8088 is. I'll report on my results when I build the project, but it will take time; shipment itself is between 3 and 5 weeks...



Hi all in this thread.

For some reason this thread is going on through an unsolicited PM exchange, addressed to all who participated in the thread.


Keep it to this thread and stop bothering me with totally needless PMs.

There's no reason to do this in private, and to keep it out of sight of anyone interested in this subject.

If i would be able to do so, i would set an ignore to anyone that continues sending these PMs.
Have a look at "blink without delay".
Did you connect the grounds ?
Je kunt hier ook in het Nederlands terecht: http://arduino.cc/forum/index.php/board,77.0.html


Hi MAS3,

I don't know either. I received a PM with an interesting suggestion. I was surprised with the PM, but me being totally new to the forum, and the sender being an old-timer, I thought that was on a purpose which I didn't grasp.

Anyway, let's continue here.

The suggestion was:

I really must point out that you do not require an 8 by 8 matrix of CMOS switches for this task.

You only require two 8-way multiplexers - 74HC4051 - with their enable lines commoned, plus one 74HC4066 to map keys which may need to he held such as Shift and Ctrl.

To which I responded:

Thank you, this is helpful and I will investigate both 74HC4051 and 74HC4066. However, since I already ordered the 8x8 matrix and actually find it intriguing to program and play with based on the online docs, I think I'll try that first for the project. Then I can try and simplify it using the ICs you mentioned. Both good ways to practice (I'm really a newbie to electronics).


Hi all,

Just to follow up on this, here is the proof of concept working :)

Thank you all again for help!



I just need to ask, why are you requiring to use 2 separate 5v sources?
Why can you not just tie into the existing 5v source?


But I am using a single power source -- from the Arduino. If I understood your question correctly.

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