[Output Devices]-
Tasks for the week:
1.Add an output device to a microcontroller board you've designed and program it to do something
2.Demonstrate workflows used in circuit board design and fabrication
3.Implement and interpret programming protocols
Assignments:
-Assignments Add an output device to a microcontroller board you've designed and program it to do something:
Introduction about Output Devices
Output Devices: According to Wikipedia, Some types of output are text, graphics, tactile, audio, and video. Text consists of characters that are used to create words, sentences, and paragraphs. Graphics are digital representations of non text information such as drawings, charts, photographs, and animation . Tactile output such as raised line drawings may be useful for some individuals who are blind. Audio is music, speech, or any other sound. Video consists of images played back at speeds to provide the appearance of full motion.
Outputing via Relay and Output
This week's assignment is to add output devices to a microcontroller board that I have designed and programmed. As part of it, I designed a microcontroller board with temperature sensor 2 output devices; a Relay Board.
Actually its kind of overwhelming for me to design a board by myself since I m not for the electronics background. My intention was to try couple of output devices by myself. So I refried the board designs that Neil provided to design my board which integrates both of them. I used Attiny 45 microcontroller for mine. So there is quite a good amount of overall change involved in this design. This allowed me to figure out the needed changes all by myself.
The following is the schematic diagram and my board design I created on Eagle. I used auto route option to create the board trace path. I made mistakes when I drew the schematic; I did not notice that the voltage regulator diagram did not get properly transfered to board airwaves.
My board design:
PREPARING THE BOARD:
Output Board PCB making: For PCB making I follow the process which I was learned from the electronic design assignment. Check in the below about output and relay board images and description about how I was made this.
After understanding the ATtiny 45 then I prepared the schematic of the circuit using Eagle. The below images depict the schematic & the board.
Schematic: After reading and datasheet and talked with my instructor, I designed board schematic with follow th library.
Some times the auto routing option keeps the traces thickness at 0.50mm which is not desirable for board milling. Hence it is always recommended to check the thickens of the traces by converting the board to .dxf format. Open the dxf file in Auto CAD and check the width of the traces as shown in th below image.
Board design traces:
Board: Now I switch to the board design and first i going to auto routing for checking the route then in edit it again for increasing the width and replace the area also, with maintained the ERC for good design:
After completing the schematic design I checked the ERC in my design |
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Export the file in monochrome format:
Export the file in monochrome format in 1000 resulation, and send it to the GIMP for further editing.
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Milling and Cut Traces:
After finishing my routing I was exporting my eagle file into the png file. I Milled that board by using modela machine. As I mentioned earlier assignment I was using 1/64 bit for milling and 1/32 for cutting the board.
Milling process going on by 1/64 end mill for milling the traceses on the board. |
After milling for cutting the outline of circuit board.Outline Cut Traces: |
Milling the board:
Milling and Cut Traces:
Now i start my milling with properly attached the PCB along the machine working body.
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Final Milling and Solding:
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Final board design- |
Description about OUTPUT board: When I was design this board, I had a plan to use of this board like LM35 temperature sensor data come from input board to output board via I2C protocol, second I want to use RTC by I2C and OLED also want to use I2C protocol. then singal pass through vai one port to Relays board. For serial communication I also keep FTDI pin. In this board all programme are control by ATtiny44A.
Relay Board:
Requirements to drive relay: In my project I'm going to use one 250W/230V heating coil which is need 7.15A more or less load needed. For this much load I going to use 5V DC and 10A load capacity relay in my relay board.
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Relay Board:
Schematice: After reading and datasheet and talked with my instructor, I designed board schematic with follow th library.This is the 1-channel relay module
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Relay Datasheet:
1-Relay datasheet
Mosfet:-
The MOSFET (Metal Oxide Semiconductor Field Effect Transistor) transistor is a semiconductor device which is widely used for switching and amplifying electronic signals in the electronic devices.
There are two type of mosfet:
1-P-channel mosfet- To turn a P channel MOSFET on, you apply a negative voltage to the gate. This voltage is negative relative to ground.
2-N-channel mosfet- An N channel MOSFET turns on when you apply a positive voltage at its gate terminal. The voltage is greater than the positive voltage supply at the drain terminal.
RELAY Board Milling and Cut Traces:
Export the file in monochrome format in 1000 resolution, and send it to the GIMP for further editing.
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Out Line Cut |
Final Milling and Solding:
Final Relay Board Design- |
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Programming the board - Challenges Faced
Arduino: First I tried to program the board by the Arduino IDE with arduino sketch. I'm using FabISP for programming but unfortunately my fabisp is not working (it show rc=-1) error. Then i used arduino as ISP, where try to program the board. First i tried arduino as 8mhz internal as Android ISP, First i burn the Arduino Uno as bootloader by selecting proper tools setup
First I connected the Arduino board to my computer. I will make the Arduino board as a programmer to program my Board. Doing the following steps as seen in the below pic's:
First I made a programmable ISP of an Arduino UNO board according to the tools setup. Then I go and select the file-example-11.Arduino ISP
In tools here I check the port, clock at 8Mhz(here I'm using internal clock speed, i didn't use resonator for checking), Processor Attiny44 and board Attiny44
Then burn the bootloaderfor making ISP
Now I'm programming the board for testing the relay is working or not, Now i have no output device (but i ordered in on-line), Is there is nothing to show proper inventory. Here we delivered the pin no and the signal value High and Low.
Here code for programming
Arduino Sketch File
To download my files click Arduino Sketch File Here
Here I Connect the Arduino board and microcontroller board with PC vai cable and also connect with relay with ISP header PIN, directly connect with USB with PC.
Connection of output board and relay board with Arduino for programming
