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Emulator of Original Dell Charger Using ATTINY85

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Re: Emulator of Original Dell Charger Using ATTINY85

#31

Post by flashingleds »

tentacleuno wrote: post #20
nanomonkey wrote: post #17

The old Dell barrel jack power supplies use 1wire communication to identify the power supply's capabilities. It would likely be cheaper to purchase a compatible 1wire memory module. Here is an article on reverse engineering the memory module. https://hclxing.wordpress.com/2014/02/06/hacking-the-dell-la...

> and the battery will not charge (the picture is from internet but it has almost identical information) Yikes! I used a no-name charger on my Dell Latitude for quite a while, and it never stopped me from charging. Just annoyed me about it (press F1 to continue on boot) whenever I took the battery out (wiping the CMOS) and didn't turn off the AC warnings in the BIOS. The one I was using didn't have a serial chip in i…

It goes further than warnings though - at least circa 2012 using an unofficial charger (or official charger where this fragile extra wire is broken) would underclock the cpu dramatically. It happened silently, such that I didn’t realize what was happening and why my laptop was so slow until stumbling upon a random forum post about it. I was pretty sour on Dell after that experience.

Re: Emulator of Original Dell Charger Using ATTINY85

#32

Post by sannee »

londons_explore wrote: post #23
tpmoney wrote: post #15

Earlier quoted context omitted.

The obvious answer would probably be the size and the dip formfactor. Sure you can get more capable BGA packaged chips, but how many hobbyists have the ability to properly solder in a BGA?

The 328 is also available in dip...

Was available in DIP, was... None of the standard suppliers have them at the moment and I have some doubts they are ever going to be available again, considering the rather limited demand.

Re: Emulator of Original Dell Charger Using ATTINY85

#33

Post by tentacleuno »

flashingleds wrote: post #31
tentacleuno wrote: post #20

Earlier quoted context omitted.

> and the battery will not charge (the picture is from internet but it has almost identical information) Yikes! I used a no-name charger on my Dell Latitude for quite a while, and it never stopped me from charging. Just annoyed me about it (press F1 to continue on boot) whenever I took the battery out (wiping the CMOS) and didn't turn off the AC warnings in the BIOS. The one I was using didn't have a serial chip in i…

It goes further than warnings though - at least circa 2012 using an unofficial charger (or official charger where this fragile extra wire is broken) would underclock the cpu dramatically. It happened silently, such that I didn’t realize what was happening and why my laptop was so slow until stumbling upon a random forum post about it. I was pretty sour on Dell after that experience.

Really? I have a 2013 Latitude and I haven't experienced that yet (or never noticed). I still have the no-name adapter here, so I'll have to check (I only just got a proper 130W).

If that is the case, part of me wants to play Devil's advocate and say that Dell have erred on the side of caution: these no-name adapters really are quite terrifying with thermals, which makes me wonder what wattage they're actually rated for. I was frequently in WTF mode because the adapter block was too hot to keep my hand on. I didn't really have a choice either, as my battery was at like 38% capacity. This official 130W is barely warm under load.

Aside: one thing that really eek'd me out about that no-name adapter is that it has a green LED inside it. The only thing is, you can only (just barely) see it through the slits on the sides because the plastic isn't clipped together properly. The manufacturing quality is atrocious.

Re: Emulator of Original Dell Charger Using ATTINY85

#34

Post by bavell »

londons_explore wrote: post #12

I don't understand why people use the attiny85... The Atmega328 based boards have far wider software support in the arduino ecosystem, so you will typically be able to prototype a project in minutes instead of hours, and the dev boards cost the same, but the 328 ones have more of pretty much everything. The only benefit of the attiny seems to be that you can save a few millimeters of board space, but if that's your c…

I wanted to gain experience in embedded programming at a lower level than Arduino (i.e. pure C & bitbanging). They're dirt cheap and also simple enough that I can read through the whole datasheet and pretty much understand everything.

It's also kind of a fun challenge working within the limitations on both the HW and SW side.

Re: Emulator of Original Dell Charger Using ATTINY85

#35

Post by markit »

flashingleds wrote: post #31
tentacleuno wrote: post #20

Earlier quoted context omitted.

> and the battery will not charge (the picture is from internet but it has almost identical information) Yikes! I used a no-name charger on my Dell Latitude for quite a while, and it never stopped me from charging. Just annoyed me about it (press F1 to continue on boot) whenever I took the battery out (wiping the CMOS) and didn't turn off the AC warnings in the BIOS. The one I was using didn't have a serial chip in i…

It goes further than warnings though - at least circa 2012 using an unofficial charger (or official charger where this fragile extra wire is broken) would underclock the cpu dramatically. It happened silently, such that I didn’t realize what was happening and why my laptop was so slow until stumbling upon a random forum post about it. I was pretty sour on Dell after that experience.

This happens even on new Dell machines, even if the PSU is detected but a lower wattage than the shipped PSU. I have wondered if it affects Linux more than windows though

Re: Emulator of Original Dell Charger Using ATTINY85

#37

Post by tentacleuno »

tentacleuno wrote: post #33
flashingleds wrote: post #31

Earlier quoted context omitted.

It goes further than warnings though - at least circa 2012 using an unofficial charger (or official charger where this fragile extra wire is broken) would underclock the cpu dramatically. It happened silently, such that I didn’t realize what was happening and why my laptop was so slow until stumbling upon a random forum post about it. I was pretty sour on Dell after that experience.

Really? I have a 2013 Latitude and I haven't experienced that yet (or never noticed). I still have the no-name adapter here, so I'll have to check (I only just got a proper 130W). If that is the case, part of me wants to play Devil's advocate and say that Dell have erred on the side of caution: these no-name adapters really are quite terrifying with thermals, which makes me wonder what wattage they're actually rated…

Update: looks like you were right[0], although it doesn't affect my 2013 Latitude, if Linux's cpufreq diagnostics are anything to go by.

   # Running on battery power.
   cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq
   3500000
   3500000
   3500000
   3500000

   # No-name charger inserted.
   cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq
   3500000
   3500000
   3500000
   3500000

   # Genuine charger inserted.
   cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq
   3500000
   3500000
   3500000
   3500000
[0]: https://unix.stackexchange.com/questions/576692/ignore-ppc-s...

Re: Emulator of Original Dell Charger Using ATTINY85

#38

Post by tentacleuno »

markit wrote: post #35
flashingleds wrote: post #31

Earlier quoted context omitted.

It goes further than warnings though - at least circa 2012 using an unofficial charger (or official charger where this fragile extra wire is broken) would underclock the cpu dramatically. It happened silently, such that I didn’t realize what was happening and why my laptop was so slow until stumbling upon a random forum post about it. I was pretty sour on Dell after that experience.

This happens even on new Dell machines, even if the PSU is detected but a lower wattage than the shipped PSU. I have wondered if it affects Linux more than windows though

A quick way to check would be to `cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq` while you're on battery, then do it again after you've plugged in the PSU. I checked mine[0] and it apparently doesn't affect this model (the adapter I tested with does not communicate with the laptop at all).

[0]: https://news.ycombinator.com/item?id=30458632 (god I really suck with the links today, lol)

Re: Emulator of Original Dell Charger Using ATTINY85

#39

Post by ticklemyelmo »

sidewndr46 wrote: post #19
hwh wrote: post #16

Earlier quoted context omitted.

An MCU is a chip in a package that just cannot interface with anything your consumer PC or notebook comes with. You'll need an adapter in any case. That said, lots of current MCUs come with UART, I2C and/or USB bootloaders allowing to erase/program (if not disabled). This bootloader is typically included in factory ROM, not to be programmed by you or a third party.

What? Why couldn't an MCU interface with my computer? It's not like it has special electrons or something in it. I regularly program atmega chips with a cable I made that plugs into the parallel port on the back of any computer that has one. If you have a couple GPIO pins on a motherboard, you can probably program almost any MCU with with it. The only exception is if the motherboard GPIO was say 3.3v and you had a 1.…

So do you jam the chip into the parallel port? Or do you...use an adapter?

Re: Emulator of Original Dell Charger Using ATTINY85

#40

Post by unwind »

titzer wrote: post #8
alexk307 wrote: post #3

Awesome work. I just dove into the world of AVR programming and bought a bunch of ATTINY85's. Super easy to work with, extremely versatile, and low power consumption.

Do you use a USB programmer, or did you buy ones that have a USB programmer built in?

The ATtiny85 is a rather small 8-bit microcontroller, and controllers in that size range generally don't have peripherals on the complexity level of USB. So no, there are no 85s with USB programming support built in.

Truth be told, the 85:s are a bit old now, it was released around 2005. But even the more modern "[012]-series" [1] don't support USB, it is kind of the point. The linked Wikipedia page says:

ATtiny microcontrollers specifically excludes various common features, such as: USB peripheral, DMA controller, crypto engine, or an external memory bus.

[1]: https://en.wikipedia.org/wiki/ATtiny_microcontroller_compari...

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