Dimming TFT screen brightness - LG LED screens

LG-E2242 - 55cm / 22inch LED LCD Monitor

LG LED monitor

This screen uses LED edge lights for screen illumination. It consists of 4 strings LEDs, each string working at ~49 volts, 60mA/~3 Watts (100% brightness). All strings together uses 240mA/12 Watts. PWM is used for brightness control, setting brightness to 0% equals in 30% PWM duty cycle (~20mA avg).
This monitor contains a chip from Novatek NT68652UFG 1153-BB. There is unfortunately very little documentation found about this "all in one" chip.

Soldering qfn accelerometer to a breadboard friendly shape

For quick prototyping, I soldered wires to my Freescale accelerometer on a proto board. Used mini copper wires from inner core of flexible wire. See the picture attached for the results.

Arduino nano running at 3.3volts

An easy change to your arduino nano to run it at 3.3 volts is to use the microchip MCP1700 voltage regulator. See the picture attached were the it is mounted on the bottom arduino nano.

Schematic setup version 1

This is the first setup of my schematic.... am I missing something?

Battery options

For my SensorStick I need at least 3 volts since the DHT11 only works from 3v0, all of the other sensors can work with lower voltage. A single coin cell will not be suffice since the voltage curve of such a cell decreases a little on the longer run.

This is my target for the sensor stick:

• Runs at 3.3 volts using low quiescent regulator
• Uses an average current of 50uA
• Should run on battery for at least a year

At 50uA power usage and running for a year we need a battery that has: 50uAh*24hours*365years= 438mAh. So at least 438mAh is needed. Please note the battery internal drain, so we need more than calculated.

So here are my options

• 4x coin cell CR2032
• 6v 
• 440mAh
• Small size, but consumes lot of space on PCB since it must be directly/flat attached to pcb
• 2x Double coin cell holders will cost 1.80euro @Digikey, BH800S
• Boost converter
• single cell from 1.5v would work (AAA)
• increased component/PCB cost, around 3 euro 
• increased sleep current
• increased noise for the capacitance measurements
• Not an option due price tag.
• 3x AAA batteries
• 4.5volts 
• 700mAh
• Alkaline cells has higher voltage drop in voltage curve than coin cells
• PCB mounts cost total 1.30 euro (BK-82 @digikey)
• Seperate AAA holder box cost around 50 eurocent @ebay
• 9v block
• 9volts
• 900mAh
• Higher voltage drop, just like AAA. But since it is 9 volts battery, we have a high margin.
• Consumes a lot of space.
• Battery snap-on wire cost 20 cent @ digikey
• Battery holder 60cents @ ebay or 1 euro @digikey

Putting all the things together, I currently think it is best to use the 9 volt block with snap-on wire.