Experiments 5.2: Arduino - Serial to Parallel Conversion (74HC164 & 74HC595)

[@robdolson3656]

This was a really informative video on 74HC164 & 74HC595. Very well presented and easy to consume. Thank you for posting this video.

[@oleg4096]

Thnx man. This is the best 74HC164 &74HC595 tutorial.

[@molomono]

You can also place a transistor between the cathodes of the LEDs and the ground. That in essence dubs for a latch. I use that trick when driving larger groups of LEDs, (around 50 and up) Makes having 595's obsolete imo. Just make the base of the transistor high when you want the leds to turn on.

[@demestavr]

Great video. I was looking for the difference between the two and your explanation was right on!

[@QSQCaito]

You can cascade the 595 using the serial out. That way you wouldn't need a new wire. You tie together the transfers and send 16bits instead of sending two times 8bits.

[@darktherapy]

Really nice video. So if I were to use the 595 along with a 7 segment LED display, would I need to choose the common cathode type?

[@kungfumaster8171]

Great explain. Thanks.

[@McKaamos]

No, you don't. You can also daisychain them together. There's a serial output on the 595 that can feed the serial input of the next. Just daisychain them and connect the latches and clocks together. As @QSQCaito pointed out, you can then send 16bits out in one go, instead of 2x 8bits.

[@brub5174]

Thanks! I needed this for my leds to do at startup. I save a a lot of pins this way. But (question) with same setup if I put use the pwm to control 2 leds parallel (for fading light possibilitys) will the current affect the chip or is there a way to prevent this?

[@sanosukekursch]

Nice vid. But I guess you forgot the current limiter resistors on the LEDs. BTW, I'm planing on making a big LED matrix using my arduino, I'll use 9 8x8 matrices, it'll be a 24x24 LED matrix and I'll use 6 74HC595 to drive the matrix, I'll use a bunch of BC547 to source the current to the LEDs, but I'm not sure if the 74HC595 will be able to sink all that current from 24 LEDs since a whole column might be lit at the same time, any ideas on how I can address this issue?

[@LynkedVideos]

When you added a second 74HC595, is there a reason that you used a second data output from the Arduino, as opposed to using the Q7' pin on the first 74HC595?

[@sanosukekursch]

@DerekMolloyDCU I'll use a bunch of BC547 instead of ULN2803, since it'll be cheaper, I have one ULN2803 that I used with one matrix, worked fine, but there was only one matrix, hence only 8 LEDs per row/column, with three matrices there'll be 24(48) per row/column (bicolor matrices), I'll use transistors as drivers on the anodes, but as for the cathodes, the LEDs will bedriven by the 74HC595 itself, I would like another driver here just to be on the safe side.

[@darktherapy]

Derek, does it make writing code easier when you use the 1 extra pin to control the second 595 rather than connecting pin 9 from the first 595 to pin 14 of the second? (using only 3 Arduino pins rather than 4)

[@rodstartube]

for each aditional 595 chip, will you need an aditional wire ???

[@wanderfra42]

Sorry for being finicky but in your code you wrote that "The 8 LEDs light for one second *exactly* on each pass", but isn't there some extra time used by the microcontroller to run the "for" instructions between a Timer Interrupt (or wathever the delay is) and an another one? I'm not really sure of this, infact I'm asking..! ;)

[@dhruvshah7488]

How does the clock pin affect the ic?

[@doodh_jalebi]

Why are the LEDs slightly blinking together after each round?

[@darktherapy]

Derek would you please take a look at this video: eJN05XOxHYI I'm having an issue with one of my 7 segment displays with certain numbers, do you recognize the issue?

[@ThePhilleboy]

Very good tutorial! Thanks! :D

[@raghavendrashekhawat3249]

Awesome Thx a lot.

[@cientifico943]

Amigo tendras es esquema?

[@molomono]

Isn't it possible to ground the led's through the source-drain of a transistor and drive that transistor with a PWM pin to simulate a latch while using the 74HC164? If it is than it would be very easy to not only remove the flickering led's but you could change the duty-cycle and thus the intensity of the led's with the arduino using that method.