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Showing posts from 2017

Non-genuine battery in Lenovo X230

I wanted to refresh the battery in my travel laptop and decided that 70€+ might be a bit too much. So I've settled onto a 20€ battery, +1€ shipping, from Amazon. Here's the affiliate link:  http://amzn.to/2AUSIUW - but read before you decide to buy it. If you are ordering from outside Germany, returns will be difficult, as LiPo batteries fall under a special shipping clause. Second, the battery is suited for an X220 model, not X230. Third - and most importantly - the battery is a fake, with less than the advertised capacity. If you still decide to continue, then read on. Some nice people have managed to decrypt the EC firmware inside the Lenovo laptops and allow for a way to rewrite it: https://github.com/hamishcoleman/thinkpad-ec You can go through all the trouble of compiling it, but, to save you 5 minutes, here's the ready-built image that I've used myself, for X230  and the file for X230T , tested by readers: https://www.dropbox.com/s/pgd6o6gn3xkvl2e/patch

Inside stuff: battery-powered glue gun

I use a glue gun from time to time and was getting annoyed with the cable, finding a free power socket, was always in the way, ... So I bought a cheap battery-powered glue gun . It takes 7mm sticks instead of my old one - which takes 11mm ones. It also takes a little less space and has a better stand. The old one is rated at 15W while the yellow toy has 8W written on its label. No surprise in finding a standard 18650 cell in there. The glue stick feeds through a rubber o-ring. The only electronic intelligence can be found in the board at the bottom of the unit. The bottom of the board features a standard (90 degree) micro-USB socket and three LEDs. The LED diffuser is pictured bottom-left, while the hand-soldered "ON" switch is center. The bottom of the board has a TP4056 battery charger IC . It can supply up to 1A of charging current (and it does) and is produced by the NanJing Top Power Corp. While it looks like the same part number and provides sim

CTC / MightyBoard wireless conversion attempt

This is not a "howto" as I couldn't get it to work. But if you want to know why, read on. I've been using MatterControl instead of MakerBot for my CTC Bizer (Dual) for a while know and have been really satisfied with it. However, the best results (and control) I got with a direct USB connection. Having a 2m-long USB cable dangling is not my style so I've searched for a solution. TCP-Serial bridge There are several options here, but I've settled on ESP8266 (NodeMCU) and one of these projects: https://github.com/jeelabs/esp-link https://github.com/beckdac/ESP8266-transparent-bridge https://github.com/luc-github/ESP3D So basically the ESP8266 acts as a server which then forwards everything to and from the hardware serial connection. The first two projects work (probably) fine, but MatterControl has currently (Nov 2017) an issue with virtual serial ports. I've tried both com0com and VSPE. It runs fine for a few commands (2-5) and then it fai

Floureon BYC17.GH3 thermostat teardown and impression

I recently bought a Floureon thermostat for my electrical floor heating . and. took it apart. for your appreciation. Later edit: a lot of the users are complaining about the clock advancing a few minutes per day. You need to decide if you can live with that or ask the seller to provide details. I couldn't test this, as my unit runs from an intermittent supply. Edit 2: see a hand-drawn schematic at the end to help you with wiring. The thermostat can switch both heating and cooling loads, but the product page does not list any instructions. Fortunately, I have a cell photo of those: Outside In the box, the thermostat comes with the leaflet above, the unit, two drywall(?) screws and an external sensor. The pinout is listed on the back and this is where you should pay attention:

CTC / Mightyboard serial Wifi conversion fail

This is just a quick post while I'm working on something bigger. I've tried to get a NodeMCU module to interface to the serial port on my CTC Dual/Bizer printer, which uses a Rev G(?) Mightboard motherboard. Unfortunately, the main serial port is not exposed, just UART1. The easiest way I've found to get to the TX/RX lines was to piggyback on the resistors just before the ATMega8U chip: The 8U is used as a serial to USB converter. 5V and ground can be picked up from the exposed UART header, pictured bottom middle: I tried to use the ESP3D firmware but it only works with boards that support G-Code, not X3G. So I abandoned the project due to lack of time. The pictures above are from a few weeks ago but just yesterday I managed to put a hole in my 8U chip, no idea how that happened: So now I was forced to use my makeshift serial connection. I tried both possible solutions: https://github.com/beckdac/ESP8266-transparent-bridge https://github.com/jee

Voyager Golden Record images - processing considerations

As you may have seen in my previous post, decoding the images on the "Golden Record" is not very difficult. The problems arise in timing and amplitude issues. I've talked about timing in my previous post: there "sample rate" varies throughout the record (slowly increasing speed) and it also "flutters" throughout a frame. The amplitude issues are caused by feeding digital signal into an unconditioned/untuned analog system (probably a recording needle). Let's analyze the circle image: I will use the [vertical] scanline represented by the red dot as illustration for how a uniform background (constant color) should look. The blue trace is the actual waveform. My red line underlines the non-linearity of the recording. The yellow line signifies my expected value. So we have an inverse exponential gain that needs to be applied with respect to time, as well as a linear gain. The could be mixed into a single formula. For reference, the

Decoding Voyager Golden Record images - in Java

My inspiration started when I first saw the associated video for this article:  https://boingboing.net/2017/09/05/how-to-decode-the-images-on-th.html Without studying much further, I decided to download the sound files and try my hand at decoding the images - more as a programming exercise. I haven't studied the original article too much as I didn't want any spoilers. After struggling a bit with the data, I found that the article could not help anyway with the problems I was having. So there's the "cheater" disclaimer. Watch the end of this post for updates. Data preparation Load the sound file into Audacity, perform a normalization (Effect -> Normalize) to 0dB. Then click the black triangle above the track name and do "Split Stereo to Mono". Select one channel (entire width), File -> Export Selected Audio. I used WAV 16-bit PCM as I couldn't get MP3 to work properly in Java. That's how the waveform should look. Get famili

Zoom 9002 hardcore repair - basket case

Many years ago (circa 2004) I bought a used Zoom 9002. This worked fine for a while until the output became weaker and weaker. At some point it stopped amplifying completely. I looked online, there was at least one blog post mentioning that some electrolytic caps and the ICL7660 need to be replaced. I did that, nothing improved. I think the display also started failing. "Smart" as I was at the time, I decided that perhaps the board needed some reflowing, so I stuck it in an oven for a few minutes. Packed it good. Fast forward 10 years later: Initial condition This was literally a "basket case" - all the parts were in a basket, with no ideea what goes where.

Blackview A7 quick review

This a departure from my normal topics as there seems to be little information online about the phone. Paid ~32€ (38 USD)  for a shipped unit, so try to keep the price in mind. A unit with similar features would cost today at least 55€. In the box Phone, TPU shell, charger, cable, small leaflet. No earphones, no extra screen protectors. Compared to a Motorola Razr XT910, it looks like a monster. Performance

A look inside the Samsung S7 camera implementation

This post is less of a guide and more of a collection of thoughts. It assumes some Java and camera operation knowledge. My S7 has become my main camera since it handles low-light, uploading, water and time zones very well. It does have a few big weakness though, oversharpening being one of them and over-confidence the other. By over-confidence I mean it will gladly lower the shutter speed to 1/4s, thinking OIS will take care of the shake. It can't. The Samsung camera app on Android Nougat has shed a lot of features in exchange of user-friendliness. Gone are the sharpness controls, OIS cannot be disabled, RAW mode is available only in the "Pro" camera mode. Quite a lot of artificial limitations which third-party apps don't seem to bring back. Start To analyze the application we need to take a look at some binaries: SamsungCamera6.apk, semcamera.jar and seccamera.jar. There are some other binaries but they are written in native C (libcamera_client.so) or ev

Failed project - WiFi to InfraRed to Coffee

In one of my most-viewed articles, from quite a few years ago, I've teared down a Saeco Talea Coffee machine and noticed a strange protrusion on top. I assumed it was an IrDa transceiver, then thought that maybe it was a coffee cup detector. It indeed turned out to be an infrared port. Armed with this knowledge - and some time to kill - I've decided to try and talk to the machine, wirelessly. While it might sound easy, there are many steps involved: get hold of the service tool application, reverse engineer (RE) it, RE the service dongle, RE the machine protocol, write an IrDa implementation for Arduino, write the web app to serve the page - and coffee. Step 1 - .NET reverse engineering Ever since I've discovered JetBrains' DotPeek, my life has been changed. I don't know C#, in fact I barely know C, but I can pretend to be a .NET developer. After getting hold of the SSC2 application (that's another topic in itself) we can try to see how it can ta

Aggregated updates August 2017

I haven't had much time to write full articles but I can go through a quick rundown until I tackle each subject: CTC 3D Dual (Bizer) Printer Will create a separate article about the mods and results. I've re-tightened all the screws and tried to take out the backlash of the Z carrier. This has improved the jagged edges a bit and also reduced the noise. I made a small DIY enclosure: A4 plastic sheet on one side, the glass from a picture frame in the front, the particle wood panel from that frame in the other side. The glass frame was affixed with some 3D printed clamps as well as a modified Tic-Tac box. On the top of the printer I've cut some Ikea Schottis blinds (3$) that fold with the moving head. I found out afterwards that I'm not the first one to do this:  https://ultimaker.com/en/community/9484-umo-dust-cover I've cut a few pieces of 2.5-3mm glass to the bed dimensions. Rather, I've had a glass manufacturing company cut them for me (<10$). Th