Hacking Together a Serial Backpack

A serial backpack is really nothing more than a screen and some microcontroller glue to drive it. And a hammer is nothing more than a hardened weight on the end of a stick. But when you’re presented with a nail, or a device that outputs serial diagnostic data, there’s nothing like having the right tool on hand.

1383501485329153153[ogdento] built his own serial backpack using parts on hand and a port of some great old code. Cutting up a Nokia 1100 graphic display and pulling a PIC out of the parts drawer got him the hardware that he needed, and he found a good start for his code in [Peter Andersen]’s plain-old character LCD library, combined with a Nokia 1100 graphic LCD library by [spiralbrain]. [ogdento] added control for the backlight, mashed the two softwares together, and voilà!

A simple screen with a serial port is a great device to have on hand, and it makes a great project. We’ve seen them around here before, of course. And while you could just order one online, why not make your own? Who knows what kind of crazy customizations you might dream up along the way.

30 thoughts on “Hacking Together a Serial Backpack

        1. If you don’t use Google services they won’t know it’s you then will they? I mean you have to be a user of their services for them to build up a profile of you to be able to identify you. But after saying that if it was a widespread practice to use google links then they would be able to build a small profile on you.

          1. Where “use Google services” includes sending e-mail to anyone who has Gmail. Or visiting any pages that have their third-party cookies or tracking images.

            This is true unless you live in Europe, where tracking you without any consent is illegal. (America could pass laws to protect its citizens as well, in principle. Write your congresscritter.)

            “You actually have to be a user of their services for them to build up a profile” is truthy. If you’ve seen a plus button, you have used their services. Same with thumbs-up from Facebook, of course. You have not consented to it, but you have used their services. (In the US.) This is how they make their money.

          2. You are being tracked in some form by many ‘services’ whenever you visit websites that use google apis, facebook apis, twitter apis etc. It really doesn’t matter if you’re logged in or not, your ip address and browser settings (a lot of info is captured through user agent and javascript) is enough fingerprint to link you to any other information they have on file.
            It’s even possible they know about your shopping habits as well, through linking the mac address, wifi and/or bluetooth broadcasts of your cellphone or tablet when you walk around shops to their already impressive database.

      1. I dunno, at least you know they’re doing it. It’s been a few years though since they switched to extra-sneaky, where they show you URLs in search results, but the actual link goes through a Google referrer. There’s Firefox addons to get past that though. And I suppose there might be one for Chrome, but since the point is NOT letting Google spy on you…

        Is Firefox still creep-tracking-free? Advantage of open-source, and the project being run by a volunteer community.

        1. I just rechecked it, you can get a direct link if you put your mouse pointer on the link once, then remove it and do the same thing again and only click then. Remark: I have JS disabled for Google (of course!). No idea how this works but it seems to work. Btw, wasn’t Google SSL/TLS-only? I just had a plein HTTP-connection?!?! Anyway, i use Google only rarely when looking for hard to find datasheets or something like this. In this case i’m not so afraid of tracking, it’s not a secret that i am interested by electronics. :-) The time i didn’t know about alternatives ( https://www.startpage.com/ ) and used only Google i had some FoxReplace-rule to change the links. And my FF deletes all cookies when i close it.
          +1 for referer. I have disabled it in FF using about:config but indeed, some pages do not work. I will check out this addon, thank you for the tipp!
          Talking about tracking, there is a whole shitload of stuff used to make servers able to recognize us, beginning at static IP (yes they might be useful but not for me), persistent cookies, HTTP-headers, … I wish the people that invented all these methods would invest their skills elsewhere in something good/useful.

      2. Also a shoutout to the “Change Referer Button” add-on for Firefox. You wouldn’t believe how much shit leaks through the referer tag, even stuff you wouldn’t ordinarily expect to. At least, to me, who’s been online since Netscape 1.2, I thought I knew how the referer header worked.

        The add-on gives you a little button, with 3 options, send referer like usual, never send it, and send it just when clicking links. Some pages have anti-bot measures that check referer, so you might need to change the option sometimes. Having a little button at the top makes that simple. And it looks like a mushroom from Super Mario!

    1. Nokia screens for hacked together projects are amazing little bits of kit these days, Everyone has one or two forgotten about in a drawer somewhere waiting to get reused.
      I remember the days Nokia was king and I never thought they would be jousted from the top spot (at least so quickly). They lost almost everything all because they refused to let go of their obsolete operating system which was no longer competitive when apple/android came along. Nokia is a great case study of how mega corporations need to adapt quickly to new trends or face total destruction, Which was a shame as I have many fond memories of buying phones at more affordable prices.

        1. You are right I forgot about those ones. (moderator can you delete the comment that I made under another account as I was logged into a clients wordpress account instead of mine)

      1. hey jack you’re absolutely right about these screens… i’ve also got a few Nokia 3310s, an 8390, and a 3595 (has a color screen). I was planning to add some code for those and use a #define to compile for the specific screen/controller type.

          1. Ah, I remember when Microsoft invented Cleartype. One of the few things they actually have. It was a secret at the time, but their claim of 3x resolution increase on LCD screens only, gave the game away pretty well. They may still have a patent on it. Since the idea was using RGB subpixels to shift black / white pixels left or right by a third, it’s the same idea as above.

            I dunno if the patent’s been invalidated since then. It was kindof obvious in retrospect, but so many things are. So there might be problems in using it. That is, in a product sold to the public, in a country that actually gives a shit about intellectual property.

  1. Let’s say I DID want to buy something like this rather than make one. What would it be called? Just out of curiosity I tried finding something with this kind of functionality on Aliexpress but it’s either not made or I don’t know the magic search term for it.

    1. You should be able to find some if you search for “graphic lcd serial backpack” (with or without the word graphic depending on what you want), but as far as i know they’re not compatible with the pcf8814 driver that’s on the nokia 1100 display. The non-graphic ones run the tried and true hitachi 44780 compatible displays.

    2. Go to the Odroid website (either hardkernel.com or ameridroid.com) and look for the “Show2” device for about $25 bucks. It’s pretty nice, has a liposuction battery on board along with a 3-ish inch display all on an arduino platform so you can do whatever else you want with it too. It’s got a few buttons and led you can use too. It’s made to be a portable serial console, but you can make into whatever else makes you happy.

  2. How about a really tiny one, in a ring you wear on your finger? Would use POV, so you’d need to keep swinging your hand around.

    That, or one of those $700 1 inch 800×600 displays mentioned in the HAD on SpriteTM’s tiny ESP Gameboy. On a ring with a big lens in front of it, focussing on your eye. Like the Stanhope novelty photo viewers the Edwardians had. Actually that’d be super cool anyway. Then the upgraded Nintendo Powerglove from that other HAD article, on your other hand, for control. An invisible computer!

    Aw man now I really want one! Any eccentric millionaires want to pay me to make them a new toy? John Lennon paid Magic Alex a stupid amount of money, for what was basically a plastic box full of paralleled neon oscillators and a high voltage radio battery. The lights would blink randomly, one at a time, as voltage built up on their plates, then discharged with a flash. Lennon gave him a shitload of money for that. Big Clive’s built one of his own, and it can’t have cost more than a pound to make or Clive wouldn’t have shelled out for it. Magic Alex was a little shyster, taking fairly simple circuits, sticking glitter on, and convinving Lennon he was a genius, whose ideas would surely make millions.

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