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Here we have the Logitech LX310 ready for us to look into comprised of three parts, the receiver, keyboard and mouse.

Lets begin with the wireless receiver.

P/N 810-000594

Damn they’ve hidden the chip on the bottom side of the PCB from us!

You might be wondering where the antenna is exactly? If you look closely at the top side near the “1” chip you’ll see 4 lines going around that chip, my thoughts are that this is the antenna because they wanted to keep the receiver as small as possible that they etched it on the board directly.

1. ST 16Kbit EEPROM
I had difficulty finding the PDF for this one so I’ve uploaded it here: PDF
Hmm I wonder what they are storing in this chip, maybe using it as a buffer? It should be simple enough to hook up to the Arduino.


P/N 820-000176
P/D SC82708

A lot of screws later, the keyboard opens. The red wire up in the top left is the antenna.

The keyboard seems to be composed of 3 layers, the top layer which has a connection to ground at the top, the bottom of the 1st layer connects to the micro-controller, the 2nd layer helps to seperate the 1st and 3rd layers, the 3rd layer also has different connection to the micro.

A quick search on Google shows me that keyboards work by splitting the keyboard into a horizontal and vertical representation of keys, so for example, pressing the “A” key might represented as row 4 and column 2 activated. “S” key might be row 4 and column 3, etc.
Here we can see the different connections to the micro, 8 from the 1st layer and 18 from the 3rd layer.

Now for the bottom of the PCB.

Freescale Microcontroller
PDF and website with more information

I started messing around with the keyboard, connecting the contacts to each other and letters/number, etc would come up. There wasn’t actually a power button for the keyboard so I wondered how power it took?

It was 0.01mA went it was idle and it jumped to 5mA when buttons were pressed which wasn’t too bad.


P/N: 810-000270

If you’re wondering, that visible wire is the antenna.

1. Freescale Microcontroller
Same as the one on the keyboard

2. Avago Technologies Optical Sensor
The optical sensor to detect movement, PDF

3. Unknown Chip
Not sure what this chip
81TI (or B1TI)
AIP on it

And we’re done this time. So I wonder how worthwhile it would be to use the keyboard’s wireless connection with the Arduino, maybe for dumping a eeprom direct to say notepad? I guess it would be a bit slow compared to other methods plus you would likely need some shift registers or darltington arrarys if you were controlling it via the keyboard input.

7 Responses to “Inside the Logitech LX310 Cordless Laser Mouse + Keyboard”

  1. Wilbur Moss says:

    can not Find the Driver for the Cordless Desktop LX 310 Laser Mouse + KeyBoard can you Help Please.

  2. Michal says:

    Hello i was wonder if its posible to program that MC9S08 and maybe you have a firmware for it becaus i think my was erase aftrer 5 years of using it. If you have that one could you upload that firmware for it thanks
    My keyboard is Cordless Dekstop Wave Pro after power on only green led is blinking all the time and keyboard is not working

  3. Akash says:

    I have a iball wireless keyboard and I lost the usb wireless connector dongle. I want to make my keyboard wired instead of wireless. I operated on my keyboard and found that it has 7 7 pins CON2 jack I dont know what it does. Is that the jack for making it wired? Please help.

  4. Michael says:

    Hello Alex, do you know what kind are these switches SW3, SW9, SW10 on mobo? Would like to fix that one below scroll. Thanks in advance.

  5. sirtony says:

    Hey there – I wanted to thank you for your intuitive article. I have been using this Logitech reciever/keyboard/mouse combination for several years now. I don’t even remember how I came upon them, but they are still functional and I have grown used to them. Well the rubberized coating on the mouse and buttons got all gooey from age a couple years ago. So I had to clean it up a bit. Perhaps one day I’ll move ahead and get something shiny and new. Being from the days of Ms-dos and IBM-XT Clone for my first computer – I thoroughly enjoyed reading about my old equipment. Thanks, sirtony

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