Build an Arduino EEPROM programmer 

Excellent video but one minor comment on the code. Currently in the write eeprom routine you set all the arduino pins to outputs and then set the address and turn the output enable off. If you had previously read the eeprom then the output enable would be active and for a very short time the eeprom's data lines would be driving the bus and the arduino pins would be as well causing contention on the bus and possible damage. It would be better to turn off the output enable before switching the arduino pins to be outputs to avoid this.

The Bob Ross of electronics returns.

Im a house builder and for years I have been trying to get my head around basic programing and electronics. I have collecting machine parts and pieces. I have many little projects that require electronic control. Every machine I have built required manual control. I really get it now and all my learning has suddenly come togeather. Thanks so much for putting such a good learning video togeather. Dale

I have never seen anybody putting dry Theorie better to life than you in ur Videos. It Shows me that the Things I get thaught in uni are actually relevant and thats the best Motivation there is. Cant wait for ur next Video! Greetz from Germany

I'm currently watching through your playlist on building the breadboard computer and I have to say I really (!) like the style with the continuous commentary over the speed up parts. There are videos of people speeding up parts but they'll first finish the comment and then speed it up without any commentary then. Your style is more compact and fluent! If I had the endurance I would probably try to recreate your breadboard computer, because it actually has taught me a lot on how CPUs internally work. Sure modern CPUs are way more complicated but in their essence they work like yours, but in yours you can see how everything is ticking along!

I really love the way that you explain the workings of the digital electronics. The progression from the d-flip-flop to the shift register was awesome. You make me feel like I can do this stuff myself.

I love it! I imagine that programming EEPROM can get pretty complex with larger storage spaces, but this implementation really beats dropping 50 + dollars on a read / writer. AND you learn a lot. So thank you, from a beginner,

It’s ASMR, for computer nerds

Brilliant stuff, Ben, thank you so much - I can't imagine the effort all these videos took. For an older EE/CS engineer (like me!) they totally take me back to my roots. Especially this one: in 1978 I was in my last year as an undergrad at the Univ. of Sussex in the UK. My 3rd year project was - an EEPROM programmer. It took me a whole semester, mostly because I had to build the hardware from scratch (Z80 on wirewrap boards) and write the code in Z80 assembler (assembling it on a 64K Z80 CP/M machine!). Watching you do it in an hour or so really brings home just how far things have progressed. And yet - the principles of processor architecture are not so very different.... Thanks again!!

It’s 2:30 in the morning as I watch this video and never have I been more excited for my last year as an EE undergrad to start

Fantastic video Ben, I’m only discovering it today... I wish I watched it - and the whole set of your videos - when I was building my first projects in the 80’s ! Keep up the great work !

Honestly speaking, I have never yet seen anyone else to explain these concepts in such minutely detailed way. Thanks a lot for all your hard work and time.

Funny how computing has changed so much, yet this takes me back to my old C=128 days when I used to subscribe to COMMODORE and RUN magazines, each came with programs in machine code that you had to type in using a machine code monitor program (which you had to type in the first time you used it as well). I never really understood how that worked until now, but I spent many a day typing these codes in as my good wife set dutifully beside me reading the code as I poked them into the old machine, then saved them to a 5 1/4 inch floppy. I am loving this whole series, you make a wonderful teacher, I always thrived in college when the instructor showed, hands on how things worked, even studying the law, it was the hands on paperwork that drilled down into my brain to leave the data permanently written to my memory core.

Hi Ben. Good educational stuff. But just thought I’d point out that the issue you saw with your incorrect read following write, is because you didn’t implement the (not)DATA POLLING, outlined in the 28C16 data sheet. ie. "The AT28C16 provides DATA POLLING to signal the completion of a write cycle.” DATA POLLING uses the inversion of the most significant bit (when a post write read is performed) to indicate the write busy state. Please also note that the other read bits (other than MSB), are indeterminate during the data polling busy state. So when you saw two subsequent reads of 0x81 after writing 0x2A, you’ll note the byte you wrote (0x2A) has a 0 MSB, and the read value (0x81) has a 1 MSB (ie. inverted 0 indicating busy state). The remaining bits of the 0x81 byte being indeterminate. By the third byte read, the busy state was complete, and the 3rd address data byte, and onwards, were then correctly retrieved. Likewise, the same can be seen with your second attempt to write 0x00, where you then read 0xAA bytes. Again, note the MSB is inverted from 0 to 1, to indicate data polling busy state. In summary: Although the Write Cycle Time is spec’d as max 1ms, you really shouldn’t just assume a 1ms delay will do the trick. The correct implementation would be to perform a read loop after a write, to poll for a non inverted MSB of the byte just written, to await busy state completion.

This is the most engaging channel I've ran into in a long time. Not only because I'm interested in the content but because everything is explained so concisely and intuitively.

These videos are GREAT for the beginner Electronics learners! We did this kind of stuff back in the late 80's when I was enrolled in college! Only thing then is that we did not have the convenience of using an Arduino since they did not exist back then. But we did breadboard a manual EPROM programming circuit similar to the one in the previous video in this series for educational purposes. For larger data size programming, we actually used an EPROM writer that plugged into one of the slots of an Apple II Plus computer. All you younger folks out there won't even know what I am talking about here! Kind of sad the young ones have no clue about how fast and how far technology has come in such a short amount of time. Thanks for taking me back and bringing back memories of a simpler time in life!

Thank you Ben,we love you!

Pro tip: You can use the analog pins of the Arduino as Digital GPIO pins :)

This is extremely calming, and not only is fascinating in its own right, but also makes lovely background noise. I actually listened to this while putting together a website of mine

Your videos are very cool. It takes me back to my college years when I used to build circuits like this. I still have one on a breadboard that I made in the mid 80’s. I have to say, your wiring is much cleaner than mine.

I used to do minecraft redstone when I was like 12, and these videos are much easier to understand because of it. The most complicated stuff I made was a full-adder. Anyway nice videos you make computers seem so easy to understand!

Great video not only for electronics but also programming. Thanks.

As usual, excellent content. Humble, to the point, clear. Ben, your work helps to quickly understand things, which are not so clear when reading datasheet. I wish you all the best!

Another video of Ben I loveto watch. As always very interesting, I'm learning so much. I had no idea how an Eeprom programmer worked and Ben, you make it so simple to understand. And honestly even your code is elegant and it real pleasure to watch you write it.

This video is awesome & very well done, keep it up. Best shift register explanation ever too, you could chop that up into its own video even!

If Ben is improvising during the video, then he is a super star indeed and if he really plans each step on the way then he is a super super star ....really unbelievable great tutorial ....well done young man.

So nice to have these kinds of channels as an engineering student! Not all the science channels have to appeal to the general public, and the educational value on these videos are just immense!

Ben, excellent video very informative and well laid out. Great starting point for people that want to venture into this area. I wish had something this clear a few years ago when I started playing around with eeproms. Keep up the good work looking forward to to your next videos.

Exelent tutorial. Now I know how shift register is working.

If you read the datasheet carefully, it says if you read from the chip, and the write cycle is not yet finished, the MSB of the data will be the INVERSE value of the data you are writing. The other data outputs are undefined at this time. After pulsing the /WR line, you should enable the chip output and monitor the value of IO7, waiting until it matches the MSB of the byte you wrote. That way you're not stuck inserting arbitrary delays in your code, and you can never enter in to a race condition with the write cycle, like you are here. This is the reason you get funky data when reading the chip, directly after writing to it.

Your videos are impressively clear to comprehend. Please, keep making them!

Wow. First video I've seen using shift registers for a purpose instead of just explaining how they work. Good Job!

This is great. I'm new to Arduino so I really I like seeing random chips that I've never seen before like that shift register and how it works. Could you do a series showing more random things like that? There's projects in the past that I would have used a shift register if I had known about it but I didn't at the time!

To get rid of the delay(10) in the writeEEPROM function, you could take advantage of the inverted data polling feature of those EEPROMs that lets you directly determine when the write cycle has completed. After clocking the write enable pin, switch back to reading that address and wait until the data you wrote appears on the output pins. A few other possible enhancements I thought of while watching that I might try - Speeding it up by cycling the addresses in a De Brujin sequence rather than incrementing the address. That way only a single bit has to be shifted in for each write. - Using the SPI perhiperhal to write to the shift registers much faster than doing it in software. The 74HC595 is rated for up to 25 MHz, significantly faster than even the CPU clock speed for the arduino. Hook the shift register data pin to MOSI, the shift clock to SCK, and then you only need to use a single digital pin for the latch. - Re-wire the data pins to be in the correct order in the GPIO pin registers, so that the byte can be reassembled more quickly: read the two pin registers, mask off the relevant bits, and just or them together.

Jesus you’re so smart man. Seriously a lifetime of knowledge it seems like. You explain things so well and simply, too. I just graduated college last year and I have so much to learn. I love watching your videos and learning things I’ll probably never do but I still enjoy learning about it. Thank you man and please keep it up. Great work

Thanks for posting your videos, very well done. They answered many questions I've had as to exactly how data can be stored and used by a computer. I hope your able to keep producing more videos in the future.

You could have used the analogue pins as outputs also. Pns A0 - A5 are on PORT C which can be used as normal IOs 😁 A6-A7 are only connected to the ADC MUX though.

This is a wonderful video with everything clearly explained so even a newbie can understand it. Thanks, Ben. If anyone is wondering, this circuit can be used to program any EEPROM with similar programming characteristics up to 32K by 8 bits (256 bits) without any substantial modification to the circuit (just make a few more connections between the shift registers and the EEPROM address pins) and with only minor changes to the control program. This circuit could be used as the basis for programming even larger EEPROMs by simply adding more shift registers, although there would need to be more extensive changes made to the program to account for sending the extra address bits.

WOW just found this chanel and i'm in love. So much knowledge. Thank you very much for taking your time and making these videos and keeping em commin.

I've used these shift chips many times but not entirely understood how they work. Your excellent explanation has enlightened me, many thanks.

Just FYI Arduino Nano's Pins A0 to A5 (not A6 nor A7) can also be used as digital Pins D14-D19

Instead of using the 'bool outputEnable', you can convert an analog pin to digital pin. Say we wanted to make A0 go high then low, we would do it the same as a normal digital pin: pinMode(14, OUTPUT); digtalWrite(14, HIGH); delay(1000); digitalWrite(14, LOW);

Thank you so much for explaining how old EEPROMs work :-) I plan on building a nixie tube clock with 7-segment nixie tubes and really appreciate your efforts to explain

I've been a Software Engineer for 15 years. Your videos are the first I have found the explains how software works at a hardware level. I've recently decided to learn assembly language and your videos help me understand how code is translated into byte code and how processors operate. Thank you for your videos. They are a great contribution to EE and Software Engineers alike. They have helped me reestablish my curiosity in computing.

You should disable the EEPROM's outputs BEFORE you change the data lines' pinModes to OUTPUT to avoid the potential for microseconds of conflict.

Maybe you can do a similar circuit from the pushbutton to limit the pulse of the switch with the arduino. I don't tried it yet but if you put the 680 resistor in series with the arduino pin and the capacitor, and the other leg of the capacitor to a 10k resistor and then to ground, when the arduino sends a 1uS pulse the capacitor will charge via the 680 Resistor, and while is charging you should have a logic one in the other part of the capacitor, when you set the pin to low then the capacitor discharges via the same resistor as before, so it shoul work as the pushbutton, if you want to get the low pulse just change the 10K resistor to VCC and the Arduino pin to High, and it should do the job :/ I repeat, I dont tried it yet, but it should work

this video is so well made, i have no idea how you did it. keep up the flawless content ♡

This is a great tutoral. I wish that they would have done Lab work like this in Digital Electronics at Ivy Tech State College. It makes things so much easier to understand and you rolled 4 days of lessons into a half hour thats understandable. Keep up the good work.

44:01 I think you could use the RC circuit you made before with the delay to be more precise when writing on ROM

Hello Ben, Nice Arduino EEPROM programmer I was hoping you were going to use a cheap simple microcontroller to program EEPROM with the Binary to 7 Segment decoding data.

I did not follow all (most) of that but as good a tutorial as I have ever seen, well presented. Took me back to my Nascom days when I had much more understanding. This old fella is going to trawl through this vid quite a few times more yet. Many thanks.

Hallelujah !!! That was a tough one for me. I had my ups and downs with this one, but never gave up. After finishing the project, I looked though your updated code and added the Erasing EEPROM, which helped, as the first time I ran it, it did not appear to be doing anything, but I guess that is because it takes a little while to fully erase. Anyway, thank you for the video, it was FUN !!! Even though I do have a simple($40) programmer, that I could use. It is always fun learning new ways of doing things. Thank you

This channel is soooooo relaxing 😏😏😏

You don't have to convert the truth table binaries to hexadecimal, you can just write them as binary literals in C: '0x4C' is equal to '0b01001100'.

This is a great video - Thankyou for making content like this - One of the best videos i've found on a personal journey trying to build a Z80 based computer from scratch (with very little previous electronics experience) just to learn new things (I currently have an Arduino faking memory) - i've learned so much watching this, you explain things clearly and simply , i'm pretty sure i can go away now and implement a lot of what you've explained because i actually understand it, rather than just copying it.

Man you are great! I get goosebumps while watching each episode. Good stuff.

"Thank You", thank you very much 😀 This is a REALLY good tutorial 😎

*sigh* I already know all this. When are you going to teach me something I don't already know? (lol this was as sarcastic as I could muster. I bow in the presence of a Master) This was brilliant. So clever.

Can not believe you putting so much effort for explaining. Thank you

I'm building up something like this- but for mine, I went with counter chips, 74HC163s with their Qn outputs wired to their Dn+1 inputs - Since count enable is active high and load is active low, I just connect them together as a mode bit, no need for glue logic. Effectively it works as either a counter or a shifter, depending on the mode bit- so I can shift in an address, flip the mode bit, then step through further addresses with just one clock cycle each. I was originally planning on having the data pins do double duty and use a '138 to address which counter to load with 4 bits at a time, but watching this video inspired the shift register configuration, and it just happened to work out really nicely.

The main problem is that he is using the wrong datasheet. The -25 after the device name is the speed grade and this is very slow. I didn't find the good datasheet too be I saw some -20 that had a 10ms write cycle... The cleanest solution would be to implement the data polling test that checks if the write cycle is finished. This way you can adapt the write speed to the actual performance of the eeprom whatever grade or brand you use.

This is one of the most amazing channel here on RU-vid! For GEEKs!!! BTW, from where did you got all this knowledge of electronics and computer architecture? Salute to you👍👍

more excited about the video drops than favorite TV show. thanks man

Before I found your channel the best thing I could do is program a tiny 45 with my arduinos. Thank you so much for making me understand that I can program so much more!

for some reason this made me want to build an electromechanical EEPROM programmer that reads punched cards, or even those scantron cards from school that require a #2 pencil

Thankyou for posting this! :) This is extremely helpful as I'm about to embark on making my own microcomputer :) One thing though - noticed you used D13 as the write enable - this pulses everytime a new program is uploaded to the arduino, I believe that would cause data to be lost from the EEPROM? Would it not be better to use one of the analog lines as a digital output?

I enjoyed the video very much, helped me to recap on some of my rusty digital principals.Your command of C is really good. With reference to so many viewer asking why not just use a 7 segment driver chip...that was not the intention of this exercise. It is a great tutorial on the making of an eeprom programmer. It is not only to program a 7 segment display. If you follow the further you will notice how this programmer is used to change code in the MCU.

This is the best video about shift registers what i see on yt, i learn a lot from this film. I watched more of Your video and i learned a lot from them. You are excellent teacher!

On code style, usually you'd make the condition on the for loops use < instead of

tanx, for note with (chip datasheet): delay(10); (45:45 add delay(5); (5ms?)) 49:06 "ups?" (reading wrong 51:26) 51:55 (what datasheet say AT28C16 / AT28C16E (write cycle time)) (Typ 0.5ms , Max 1.0ms ) (how Arduino get 0.5ms or 100us or 200us?)

Brilliant. I was just about to build this from scratch using an ATmega 2560 for 16 digital pins. This saved me loads of time.

This series is awesome! Im a total beginner but im hooked. Keep it up!

What is the wire you use for this? Your cable management is awesome.

Ok, I know I'm not crazy, now. There need to be breadboards with rows that have more than 5 pins.

Your videos are a great teaching aid. You go into detailed explanation in a way that is easy to understand and create something usefull

Awesome, That's what I thought you were going to do. Just another use for Arduino and great example of using functions and c code. So much to do so little time.

Seems like it would have been simpler just to have an address register, and a data register, load them directly in separate steps, then pulse the write signal.

This is how to really stop worrying and understand electronics!

By just watching it is not enough, I have to get my own chips, proto boards, cables and so on. Get all ready and try to follow. Great videos. I will make your video lessons one of my projects. Thanks.

Every time I see people using neat wiring on breadboards remind me of high school where we also were required to trim and bend every jumper to the proper length and make it neat. Now days, people just throw jumpers in and you can never troubleshoot them easily. Thank you!

I bugged out on 22:00 where you convert address 1234 into binary. How do you do it so fast ? Did you cut the video to calculate it? Great and clear video anyway, thank you.

Good video but do you know that you can use pin A0 to A7 as digital pin on the ardino

Thanks so much. i was just looking for a propitiation check on EEPROM and you were very clear and concise.

Ben - THANK YOU for this video! Thanks to your tutelage, I was able to easily create a modified design of your circuit for a 16KB D27128A EPROM. That EPROM is used for the OS ROM in my old Atari computer. I was able to pull the data off my custom OS EPROM and dump it into a binary file to load into my old system (which now has a way to load ROM files for the OS). Mine doesn't look as nice as yours does though - I don't have customized lengths of wire that fit in nice and neat. You saved me a good bit of money too, since the programmers you can buy on Amazon/eBay are upwards of $100.

Wouldn't it be faster to just use two latches which would latch the address and data and then assert the write signal? That's just two clock cycles for each byte instead of one clock cycle for each bit :q

I thought about demultiplexer first, instead of shift register :)

I watched the three videos you posted for manipulating binary to a seven segment display, very well done sir! I am a Electronic Tech, did my schooling in 1986-1988 and it brings back some great memories of learning digital logic and serial in parallel out shift registers! Now tying all of that into an EEPROM being written to and read by an Arduino Nano! I would like to learn more about programming the Arduino's, I have a UNO that I bought awhile ago to rescue my 3d Printer that was bricked from a bad flash, so I haven't really programmed it to do anything yet, but that is about to change! Thanks Again!!!

This video is just amazing. You're knowledge and expertise in this field is unmatched, as far as I know. :p I'm ordering the Ardruino and eeprom right now. Thank you Ben.

Cool to see that I'm not alone. I've done the same for my 8-bit microcomputer project (6502 based). Ended up with an Arduino based programmer that has a Java-Client for easy uploading, downloading and erasing eeprom Content. github.com/mkeller0815/MEEPROMMER Additionally you should use "unsigned int" for your address variable, because calculating with a signed integer can have unwanted effects.

How do you get your wires the perfect length?! Haha

Fascinating .... the words can't express how much I appreciate this explanation.

thanks for your schematics and extensive knowledge about the arduino and accessories! youve been an inspiration for me

"getting really old" This used to be the ONLY way to boot some legacy hardware... you had to manually program in the boot sequence with switches just like this.... Those long winter evenings in the server room used to just fly by......

Before writing 42, you should have made sure you knew where your towel was.

of all the things in this video, what impressed me most was how you read the binary out forwards while moving your left hand left and your right hand right without sliding off point. well done I suppose lol

These videos really help in de-mystifying these mystical things. Much appreciated 👍🏻

Do the "analog" pins can be used as digital i/o? I think you can... On PICs thats completly possible!

34:02 I’ve had that problem too where my computer won’t recognise the Arduino unless I restart it It’s very strange

as has been pointed out, all pins on most modern micro controllers can be used as I/O normally with a digital aspect it is referred to as tri state logic meaning it can, sink and source current as well as being high impedance as an input.

You earned a subscriber with this video.... just getting into Arduino and already have a coding background so this is something I already wanted to tackle on my way to reprogramming BIOS chips.