Life on FR4

!!!Allwinner A31!!! Quad-Core 64 Bit ultra cheap SoC for everyone!! Yeah sound good...but the truth are awful is some case . First of all do you know about the Banana Pi M2?The Banana Pi M1 (A20) was the killer of the first generation Raspberry pi . After the second generation Rpi was released the Bpi m2 was released too . But where is it ? The Bpi m2 was a huge fail (M3 was changed the M2 very soon) . Nobody care about the A31 SoC linux support . No community,no projects,hack or any interesting thing about this mini ARM board. And what about the android support? Little bit better but not in all case. My new target is a A31 SoC based tablet with nice screen and big battery . But something wrong because I can't turn on.And my journey started here. I took it apart and try to locating the wrong parts.I started on the power rails : Sorted Main Board WorkBench  APX221 is a dedicated Power Management Unit for A31 SoC. You can find a lot of informations  on sunxi linux...

OP3n DOTT ?! WTF ... newest company "from china with love". Promoting nice 8" Intel CPU based tablet and smartphone, both with android. And here is some accessories for their smartphone and tablet,bluetooth headset BT 4.0 Integrated MIC NFC sounds good!Get one and take a part. What's under the hood?The Op3n dott don't want to reinvent the wheel. As you can see he used the well known CSR-8635 module. Limited Datasheet and tools for flashing available on the net,not bad! And what about the sound quality?Not too bad but if you want to get some nice quality tones probably you will be disappointed. Keep in mind this is a 35$ BT headset :D Luckily I have a lot of headphones and headset parts. For example a  pair of sennheiser HD-180 headset speakers,and this is much better that the original ones. The stock speaker The stock speaker Truly integrated speaker by Sennheiser.This was fluid XD? upgraded speaker Now the sound quality ...

The simples method to manufacturing PCBs at home is the toner trasfer method.But the laser printer is the most important a part of this technic and the laser printer is expensive stuff for only printing some PCB / month. The cheapest method to manufacturing PCBs at home is using alcoholic pen and drawing the traces with your own hands . But our hands resolution or the precision is not enough in most case. The PCB plotter machine with CNC controlling are the solution of this problem. I spend my last weeks to build this PCB plotter machine from 2 CDROM driver and a floppy driver. The parameters: 38mm*38mm Workspace (enough in most case) 0.0735 mm / steep (in halfsteeping mode) Parts that is used: As I said  : 2 CDROM and 1 Floppy driver 3 * L293 Dual Full Bridge Motor Driver IC Power supply of course ATMEGA88 and USB2Serial bridge Some wires and pin headers The full cost is about 15$!! The manufacturing flow I using Eagle Cad for design the circuits a...

A few week ago I bought 5 piece  of ATMEGA88-PU on second-hand market  (www.vatera.hu).The cost was holly low about 0.3$/piece. I'm going to design and make my own arduino like development board for easy prototyping . I used Eagle Cad for designing the PCB and I used  toner transfer method for etching the PCB . Finally my first DIY PCB and my devboard for atmega88 is ready to go. This was the first prototype: Pin header for PORTB,PORTC and PORTD,ISP for Programing,GND and Vcc headers and Reset button 1 weeks later I realised some weaknesses: the power headers was broke I need to plug 2 usb device into my PC.A programer and an USB-Serial converter I can't see any heartbeat (onboard leds)  I pimped up my board with some goodness: Arduino bootloader for programing over UART (  thx  ) Extended Power headers  Onboard dual leds and voltage regulator The other stuff on the left side is USB to Serial converter from Sony...

This article based on this page. Lcd chip: based on PCF8558 I created my own  CPU FAN controller for my PC because my cooler was generate a lot of noisy.I used this LCD to print out the temperature data and PWM duty in %. The LCD use standard I2C interface for communicating with other stuffs.You can find the pinouts on the linked site. You can find more details on my GITHUB: https://github.com/zoon81/tinnyI2C Here is some pic: