Programming salvaged chips without assembly? - Page 1
Forum section: electronics / beginners

author: laserpon3
author_rank: Contributor
timestamp: December 03, 2012, 01:42:13 pm
content: Hello Everyone,First of all I'm kinda new here, so my apologies If I post this in the wrong place or anything.So I have a question:I'm actively trying to advance in C language programming but am put into a situation where I'm not sure if I even can avoid assembly.I have lots of tools like electric desoldering pens and a heat guns, etc to salvage IC's and lots of electronics at hand to salvage from.The most focus im putting on when salvaging are the EPROMs and EEPROMs.Basicly I want to repurpose them if they are up to the task specification wise.Be it either for just little devices doing simple tasks, to maybe some things more complex later on.Examples currently would be: controllers that can interface with pc (mostly not focussing on standalone here yet)I do have a programmer which ist the willem programmer (and I also own the arduino) but am completely new to assembly (not even sure if I should bother).The thing I was wondering for instance is if the C language to assembly conversion is good enough to be used to reprogram and repurpose IC's.

author: c4757p
author_rank: Super Contributor
timestamp: December 03, 2012, 02:51:34 pm
content: Good luck with the salvaged chips. They're all going to be different types - every one has its own quirks, its own development system, and so on. Best to stick with one kind. And yes, I'm sure you'll bump against assembly sooner or later, especially with the cheaper, more limited MCUs you'll salvage from most electronics. (Advice from personal experience: PIC assembly is easier than AVR, as AVRs are targeted at C. No experience with any other microcontrollers. I'd put in a recommendation for one of the two, biased towards PIC if you want to do assembly, if you want to choose a good starting micro.)Also note that a lot of microcontrollers aren't reprogrammable; many cheap, high-volume devices have the MCUs made with firmware hard-wired.Your third paragraph makes it sound like you're salvaging EEPROMs and expecting to program them. Excuse me if I misunderstand, but you do know they're just memory, right, not a controller? You can program them all day long but they won't do anything.

author: laserpon3
author_rank: Contributor
timestamp: December 03, 2012, 03:14:34 pm
content: aaah sorryI do understand now though! Thanks for clearing it up.Still got a lot to learn as you likely notice.Currently im using my willem programmer to make snes flash carts and gameboy flash carts so thats not really much no.So I should focus on one brand when it comes to IC programming? or really once specific type of range of IC?My primairy focus currently is mostly to make cheap HID that interface over USB, I prefer building something from scratch here, the salvaging idea seemed really cool.(Imagine making a controller from just salvaged parts).But I guess I will have to make changes in that mindset.If you have any more tips i'd love to hear themBut this at least helps me a bit further.

author: c4757p
author_rank: Super Contributor
timestamp: December 03, 2012, 04:20:41 pm
content: I would focus on one brand if I were you - there's a lot to learn with each chip. Maybe keep using your Arduino, but ditch the Arduino software. Once you've mastered that you can move on, but they all vary significantly.If you want to make a cheap HID USB interface and like the idea of salvaging stuff, have you considered stripping down a keyboard? Might be something interesting in there.

author: deephaven
author_rank: Frequent Contributor
timestamp: December 03, 2012, 04:35:41 pm
content: Microcontrollers these days have built in program memory - usually 'flash'. If you're keen on using EPROMs you're going down the 'retro' route meaning using them with very old-fashioned microprocessors like the Z80, 6809, 8080 to name a few.If you want to do something modern, then those EPROMs aren't going to be of much use.

author: laserpon3
author_rank: Contributor
timestamp: December 03, 2012, 07:12:25 pm
content: So when it comes to salvaging.Capacitors (off course tested with a multimeter for their quality)Resistors and potentiometers and some SMD things and memory and the likes (basicly anything except microprocessors) are really the only things that are worth salvaging these days?I wish there was something I could learn that sorta can be applied to using other microprocessors :/That way I don't have to stick with just one particular thing.I also tried processing but it doesn't really work at all :/The problem really im having a lot is having the arduino be seen as a HID device or it properly interfacing with my pc directly other then executing programs from the arduino itself.While arduino works well and some of the microprocessors being quite cheap a piece (2,50 euro a piece for some of the atmega's) those cheaper ones don't offer that much I/O pins.The atmega2560 for instance has quite a lot but is also quite pricey being a whopping 15 euro's a piece.I mean it doesn't sound much, but if you want to make a bunch of seperate periferals, price go's up quick.I want some cheap ic with a lot of I/O pins or the expendability with not a hefty price tag for more.I don't mind if it's a small IC which is SMD like the atmega 2560.I can etch my own board.Basicly looking for a cheap IC with a quite decent amount of I/O pins orWhile stripping down a keyboard does work.It's not really ideal for sliders or joysticks and the likes.it also doesn't allow too many simultanious buttons because the way how keyboards work.

author: c4757p
author_rank: Super Contributor
timestamp: December 04, 2012, 02:50:47 am
content: QuoteThere is - MCU programming in general. All the specifics differ widely, which is why I think it's good to focus on one group at a time, but the style of programming is similar. Once you can program one microcontroller you can learn others. Just master one first.QuoteA multimeter won't tell you a thing about the capacitor's quality except "Yep, it's gone short circuit" or "Whoops, no capacitance left!" which are both rare modes of failure.QuoteThat is a ridiculously over-spec'ed controller for almost any purpose. How about one of these:ATMEGA32A-PU: 32 KB/2 KB in DIP-40, US $3.79 eaATXMEGA64A3-AU: 64 KB/4 KB in TQFP-64, 32 MHz, US $5.88 eaPIC18F4550-I/PT: 32 KB/2 KB in TQFP-44, 48 MHz, US $5.48 eaPIC18F65K80-I/PT: 32 KB/1 KB in TQFP-64, 64 MHz, US $4.65 eaAnd so on. Sorry about the U.S. prices.

author: c4757p
author_rank: Super Contributor
timestamp: December 04, 2012, 02:55:52 am
content: If you need a lot of I/O you shouldn't be using MCU pins unless you need awhole damn lotoffastI/O. That's what I/O expanders or the humble shift register are for. You can bang some data out to a 74HC595 and in from a 74HC165 pretty quickly.Edit: My New York State filthy mouth doesn't seem to fit in on this forum

author: T4P
author_rank: Super Contributor
timestamp: December 04, 2012, 09:52:53 am
content: Heh 8 bitters. ST's Cortex-M0/M3 (STM32F0 and F1) start from 48pins and have 37 I/Os along with costing only 2-3 buckshttp://www.newark.com/stmicroelectronics/stm32f100c4t7b/ic-mcu-arm-32bit-48-lqfp/dp/65T3764

author: laserpon3
author_rank: Contributor
timestamp: December 04, 2012, 01:19:01 pm
content: Awsome!Thank you so much for the advice guys!I apreciate this a lot.I like this forum already!I will also contribute by sharing my knowledge in the field of lasers.As that is my field really

author: PhynixViking
author_rank: Regular Contributor
timestamp: December 06, 2012, 09:17:08 am
content: WOOT!!! Good luck with your salvaged chips! I'm planning to do just about the same thing. I've been stock piling them for years and just recently started to learn some programing languages. ^___^

author: ptricks
author_rank: Frequent Contributor
timestamp: December 06, 2012, 01:01:02 pm
content: You don't absolutely have to know assembly but I highly recommend it. I am mostly a PIC and ARM person so that is where my recommendations are.PIC has a TON of information online since the chips have been around for over 20 years . The problem you will run into with pulling chips off boards is a lot of them will have house markings, meaning just a number that doesn't tell you what the actual chip contains. The chips are also often OTP or one time programmable, you can't erase the contents.If you want to do USB easily I recommend a PIC18F2550 or PIC18F4550 chip and JAL. JAL is a very easy to learn pic programming language that is free and it has easy to use USB routines. The biggest thing with starting out with PIC is the need to program the chips but you have a willem programmer and that will work for the PIC I recommended.http://picshell.ovh.org/ps/