Evaluating a device

I love to go to antique mall and flea market and look to find pieces of technology to play with.

In one of my tour I did find in very good conditions an Anviz FacePass Pro 7, a clock-in face recognition device for few $.

Let discover what it is, if is working and how I could use it !

Flipper Zero - introduction

Flipper Zero is defined as "hacking" tool, i.e. is a collection of devices and SW that allows to explore and interact with technology around us.

Alphaline mod. 18281

Since I have a nice bricked Alphaline MP4 player, and nobody willing or able to service it,  why not take it apart and see what is inside ?

Open the player

The shell of the player is in plastic. No screws, only small plastic hooks.
With a very small screwdriver, start to gently force close to the bottom angles of the player, where the USB connector and phone connectors are.
Then very gently start to work all around the border of the player.
A certain point it will be possible to user the fingers to gently separate the shells.

The inside

After the shells are separated, the PCB and the battery appears (the gray "thingy" on the right).
3 big chipsets are visible, plus the microphone and the pinhole camera.
Also the micro SD card reader, the USB connector and the headphone jack are visible,

The three chipset are so marked :

• ATJ2259C - ZC55LBB B7A
  The microcontroller - So far I was unable to retrieve datasheet or even basic information about this controller.
  It is a Chinese processor and in the typical Chinese way, no information are released.
  Pity. We should really stop to buy stuff produced in China.
• Infineon HYB39S25616odt
  HYB39S256160DT-7 - 256-MBit Synchronous DRAM
• PF369 - AR - 1134
  Probably LCD/touchscreen manager but like the processor I was unable to find information.

External iRobot battery charger modifications - manual

In order to test the Roomba 4xx series battery, it is needed a battery tester.
The ultimate goal is to design an automatic gadget, but first some experiments are needed.
More articles will follow.

The test battery project, uses different components.
The most important is the battery charger.
Instead to design one from the scratch, I decided to use the external iRobot charger model 02004, out of production for some time now but still available on eBay and modify it.

Battery charger 

As usual, before any modifications ...

CAUTION !
The modifications make void any guarantee and are potentially dangerous !
If you are not sure about what you are doing, DON'T DO IT !

There are some advantages to use it.

• the battery charger circuit is already done
• it provides mechanical support for the battery 
• it provides an optimal electrical connection to the battery

However it is not perfect. It was designed mainly for the traditional NiCd batteries, not the NiMh (APS - yellow ones).
It can charge them but it requires TWO charges (see the 02004 technical description by G. Plews )

Anyway, the first thing to do is to modify it in order to be able to connect the battery to the dis-charger and the voltmeter.

Battery charge modifications

The idea is to bring out the battery connectors, in order to connect the battery to the charger or to the dis-charger and the voltmeter.

To open the unit, there are 6 screws on the bottom, 4 of them hidden under the rubber pads. 

Once removed the screws the upper half of the charger separates from the base.

The electronics is anchored to the base.

There are two set of wires going in the upper shell.
Two wires are for the LED, and three wires are for the battery.
The three wires are the negative (black wire), the positive (red wire) and the thermistor feedback (blue wire).

To "bring out" the battery connections, I used a 4 pins audio connector (Radio Shack mod. 274-0002).
The choice of the connector was mostly due to what I was able to find to the local Radio Shack, it is enough for testing manually the batteries, for an automatic way more signals are needed to be brought  out.
The maximum current involved is less than 5 A, so this connector is perfect for the usage.

Pins usage :

1. + from battery
2. - from battery
3. - from charger
4. + from charger

The plug used with this connector is the Radio Shack mod. 274-0001.

The idea is to disconnect the 3 wires going to the electronic below, from the PCB with the micro-switches (only  the positive and negative connections) and connect them to the connector.

The charger with the connector.
With this modification I can now connect the battery to the charger, putting together the battery wires with the charger wires, or connect the battery to a dis-charger.

In the picture the battery is connected to the charger manually.