PAL Composite video timing

India moved to DVB T2 in 2015. I always wanted to make a system which can project images on to the biggest screen i can get my hands on. So here are details.

PAL = Phase Alternate Line

total of 625 lines

Field one + Field two  = 625 lines

each field line consist of

[ vertical sync ] [ horizontal sync + active video ]x n

each scan line if of 64 micro second. (strict constraints don’t play with margins)

each 64 micrsecond line starts with

[Horizontal Sync = 4.7 us] [ color burst = 8us] [active data] [4 us of black level] = 64 us

This scan is done from the composite line of sony playstation 2. So i am taking this as a reference.

help is taken from here

Additional notes here

Atmega32 Development Board

This development is very basic. It provides the GPIO in the form of header. As i will be using this board for rapid development and learning different coding practices.

I designed this board in KiCad – a open source l tool. From schematics and PCB layout is designed in this software suite.

Here are the schematics and PCB layout.

As i don’t have a laser printer i used the free hand sketching of traces. It is a very long and tedious process. After tracing with permanent marker and letting it dry it for few minutes. I etched this PCB in ferric chloride solution. I use very diluted solution, few grams of ferric chloride in around 200 ml water.

atmega32 dev board schematic
atmega32 dev board schematic
atmega32 dev board pcb layout
atmega32 dev board pcb layout
Drill Holes Marking
Drill Holes Marking
Copper Mask
Copper Mask

Total Etching time is around 40 minutes, After the board has been etched it needs to be cleaned thoroughly. I used utensil cleaning powder for that. And rinsed the board under water. And then let it air dry for few minutes.

Component Placement on PCB
Component Placement on PCB
Component Soldering
Component Soldering
Marking the Components on top layer
Marking the Components on top layer

The development is created. But there are few issues that came while testing the board. When i tested the board the chip does not responds. While checking for shorts or no connection on the PCB. I found that capacitor is not blocking the alternating signal. rather it is showing a short. So i had to change the 22pf capacitor with a new one and the board now works perfectly fine.

 

LDR Based Camera

Schematic of LDR based Camera
3d Rendering of the pcb’s

Scan the LDR reading with the help of atmega32 adc pins. Send the captured data to a computer using ftdi, bluetooth ,wifi or zigbee. Run any free math processing tool and make a image. Increasing the Number of ldr increases the resolution of the image.

Industrial Automation Using Internet of Things

The system will automatically monitor the industrial applications and generate alerts/alarms or take intelligent decisions using concept of IOT. The monitoring and controlling of the industrial automation is done through atmega32 microcontroller. The communication through the internet is done with the help of ESP8266 module. All the sensor data is collected and sent to the web server which processes and analyzes the data and sends a controlling response to the device for control action. The device receives the response and decodes the response message and control the stepper motor. Automation through IoT can help to get rid of the short distance communication.

Project Image
Project Image

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