Emil's Projects

OpenHardware & OpenSource

Galep4 DIL40 to TSOP48 programming adapter 4th September 2014

I own a Galep4 programmer and I wanted to read out the content of an Intel 28F640B3 NOR memory. Unfortunately this programmer only has a 40 pin DIL socket any my part was a TSOP48. Conitec (maker of Galep programmers) provides such an adapter for an extortion price of 300 Euros. For this price you can get the Xeltek 610P (which is in the same category as the Galep5 with 48 universal pins and very well supported) and a TSOP48 to DIL48 adapter . In fact I've just ordered these two for my future needs but to get the memory content out I've quickly bread-boarded an equivalent adapter.

Memory Read CycleSchematics of the Galep 210855 adapter

This entry has been cut, click to read on.

8 comments. Tags: programmers, reverse engineering.
RGB Matrix Clock 9th August 2014

This is an example of over-engineering: a clock with 4 microcontrollers! Three of these are ATmega368 which are part of a cheap development board the Colorduino. Each of these controls one third of the display namely one 8×8 RGB LED matrix. The synchronization and communication between these 4 microcontrollers will happen via a multi-master I2C bus. So far I've finished the case and I've written a simulator in GTK of the various display modes which you may download bellow.

Clock simulator
Linux versionWindows version
and GTK runtime
design file (QCAD)

This entry has been cut, click to read on.

Tags: arduino, avr, clock, i2c, rgb.
Desktop LED Lamp 2nd April 2014
Assembled Desktop LampDXF design file (QCAD)

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The lamp is extremely bright, it exceeds 5000 Lux on the desk surface with both LEDs turned on while it only draws 20W of power. The carbon tubes can bend between 45 an 90 degrees to adjust the distance to the desk surface. One (small) disadvantage is that the radiator gets quite hot and you can burn your hand or forehead if you touch it. I've measured 48 degC and 62 degC with one and both LEDs turned on.

This entry has been cut, click to read on.

1 comment. Tags: illumination, led.
Making a better HC-SR04 Echo Locator 22nd January 2014

I have bought several cheap echo location circuits from AliExpress and I'm planning to use them in one of my robotics projects.

HC-SR04 Front ViewHC-SR04 Back View

They are very cheap especially if you buy a dozen you can get them bellow 2$ shipped. Once they've arrived, to test them, I wrote a quick C test program for an AVR board which displays the distance in cm to an obstacle. The results were pretty accurate for as far as 3-4m distance for hard obstacles. Unfortunately when there are no obstacles in front of this detector or when the obstacles don't have hard surfaces then erroneous results are returned.

I wanted to understand why this was happening so the first step was to reverse the HC-SR04 module schematic.

This entry has been cut, click to read on.

152 comments. Tags: avr, hc-sr04, ultrasound.
Unlocking the Acer Cloudmobile S500 3rd June 2013

This entry has been cut, click to read on.

The "unlocked" variable is a plain flash location. So any method which will write a non-zero value at offset 0x10 from the flash partition table will unlock your phone. The "tampered" variable which only has a meaning in RAM is set when the phone is locked and the kernel doesn't have or doesn't pass the X509 certificate check.

Unlocking is performed by using a loophole which allows any phone to boot from an unsigned kernel via the UART_DM protocol. This phone has a booloader based on lk. (L)ittle (K)ernel based Android bootloader and when you issue the command 'fastboot boot some.img' you are actually sending the image via the USB line (UART_DM) and the bootloader happily runs it but sets the tampered variable. Now if one makes an image and copies just the subroutines from the leaked fw which do the "oem unlock" and makes a "kernel" image out of it (with abootimg utility) then runs it with the fastboot command it will mark the partition as unlocked.

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Tags: android, unlock.
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