In Week 7 Electronics design week i had programmed the echoboard in arduino. So in this week i thought i would do something different. I had already made a pendulum clock design in Week 8 - computer controlled cutting weekend with a normal clock. I had bought neopixel leds for converting this ordinary clock to neopixel clock. So in this week i decided to do a neopixel clock with these LEDS

.

Programming and configuring ATTINY 44 in arduino IDE was already done by me in week 7 -elecronics design week

.

Week 7 - Electronics design

.

.

.

.

Configuring attiny 44 in Arduino IDE

.

.

.

.

.

.

.

But for a backup for the assignment i thought i would program the board i had made in week 7 using c language. I had an older version of AVR Studio which was going to be used for programming attiny 44

.

.

AVR studio

.

.

Before that i thought i should understand the datasheet of the Attiny 44 microcontroller. I went though some tutorial online for the same

.

.

.

.

Attiny 44

The ATtiny44 is a high-performance, low-power Microchip AVR RISC-based CMOS 8-bit microcontroller.It combines 4KB ISP flash memory, 256-Byte EEPROM, 256B SRAM, 12 general purpose I/O lines .The ATtiny44 consistof 32 general purpose working registers, an 8-bit timer/counter with two PWM channels, a 16-bit timer/counter with two PWM channels, internal and external interrupts, an 8-channel 10-bit A/D converter and a programmable gain stage (1x, 20x) for 12 differential ADC channel pairs. It has a programmable watchdog timer with internal oscillator.The internal calibrated oscillator and three software selectable power saving modes makes it suitable for small embedded products . By executing powerful instructions in a single clock cycle the device achieves throughputs approaching 1 MIPS per MHz .It also balance power consumption and improve processing speed.

Reading Datasheet

The data sheet can be read and the specifications of microcontroller can be obtained as below

.

.

.

.

.

Next step is to create new project in atmel studio as below

.

.

.

.

Inorder to add our usbattiny programmer to our program. Select Tools->External tools. Choose title,insert avrdude.exe file in command tab. Insert argument as below:

.

-c usbtiny sp -p t44 -F -v -U flash:w:$(TargetDir)$(TargetName).hex:i

.

.

.

.

.

We will get another tool mentioning the programmer 'usbattiny'. Find the schematics diagram and select the check the input & output pins for programming. The program will be a simple one to blink an led when a button is pressed. So as per the schematic the button is connected to pin7 (PA6) and LED to pin 3(PA2)

.

Before that we should understand the basic commands in AVR programming

• DDRx: DDR stands for Data direction Register, basically it is an 8-bit register which determines whether one pin will be an input or output pin. If you want the pin you connected the LED to be set as output then you should give that value of that as 1 on DDRx. Example I connected my LED to PA7, hence I have to make it as output in DDRA. Hence I give the code to set the pin PA7 as output by writing. DDRA=0xff; This is HEX equivalent for DDRA=ob11111111. This will set all the pins on the Port A as output pins.
• PORTx: while DDRx denotes the direction of the Pin, PORT denotes the state of it. That means if I give a value 1 in the PORT register of that pin It would be set to HIGH, or 5V in case of the micro controller.
• PINx : PINx register is a dynamic register whose value will be automatically updated based on the received values of the state of all pins, so 5V to that pin will write 1 to that register

.

Write the program as per the pin usage as below

.

.

Build the program and send it to micrcontroller

.

.

.

OUTPUT

.

.

Group assignment

.

Compare architecture

ARM ARCHITECTURE

ARM, previously Advanced RISC Machine, originally Acorn RISC Machine, is a family of reduced instruction set computing (RISC) architectures for computer processors, configured for various environments.Processors that have a RISC architecture typically require fewer transistors than those with a complex instruction set computing (CISC) architecture (such as the x86 processors found in most personal computers), which improves cost, power consumption, and heat dissipation. These characteristics are desirable for light, portable, battery-powered device-including smartphones, laptops and tablet computers, and other embedded systems.] For supercomputers, which consume large amounts of electricity, ARM could also be a power-efficient solution. Most of our mobile phones are based on ARM and now it used on server's and super controllers.Raspberry Pi is Single board computer that based on ARM

STM32

STM32 is a family of 32-bit microcontroller integrated circuits by STMicroelectronics. The STM32 chips are grouped into related series that are based around the same 32-bit ARM processor core, such as the Cortex-M7F, Cortex-M4F, Cortex-M3, Cortex-M0+, or Cortex-M0. Internally, each microcontroller consists of the processor core, static RAM memory, flash memory, debugging interface, and various peripherals. In here Fablab Kochi we have the STM32F401 series Nucleo development boards.it's a part of the STM32 Dynamic Efficiency™ device range. These devices offer the best balance of dynamic power consumption (in run mode) and processing performance, while integrating a high number of added-value features in packages as small as 3 x 3 mm. The MCUs deliver the performance of Cortex®-M4 core with floating point unit, running at 84 MHz, while achieving outstandingly low power consumption values in run and stop modes.

.

Neopixel clock

.

I opened fusion 360 for my clock design. Inorder to accocmodate the neopixel clock inside the space for clock portion in my design, i synced by autodesk eagle and fusion 360 by signing in with the same accounts on both

.

In create open 'Create PCB'

.

.

.

.

Make a circle as per required size

.

.

.

In Eagle click on fusion sync, select the project for which the pcb needs to be synced. Press ok. After that we could push and pull the deisgn changes from fusion

.

.

.

.

Download the github file for neopixel from this link and add it to Eagle library

.

.

.

.

Study the data sheet for pinout and current specifications

.

.

.

.

As i am planning to have 12 neopixels for clock hands and program it with attiny 44, place the components from library as below

.

.

.

.

.

.

Switch to board view where we will see the outer line of PCB synced from fusion 360. After placing the components place the neopixel LEDs in circular array from tools->element array placement. The radius of the circle can be provided in accordance with clock design

.

.

.

.

The neopixels will be arranged as below. Place other components and position it correctly to 'Autoroute'

.

.

.

.

Give proper design rules and click autoroute

.

.

.

.

After autorouting we will obtain board as below:

.

.

.

.

Files for PCB

.

.

.

.

Vinyl cutter

As the PCB we have in our lab was not adequate for cutting PCB of size 120mm, I decided to do it on flexible PCB I knew that it was a difficult task, but i decided to give it a try. Inorder to be sticky on the other side of PCB and to get enoough length for the vinyl cutter to move through the cut piece i decided to stick it on a white transparent vinyl sheet as below:

.

.

.

.

.

.

But it failed as the size of the white vinyl and copper PCB fell out of rollers in vinyl cutter. It failed multiple times. So i decided to use lengthy yellow vinyl sheet for pasting the copper.

.

.

.

The image for cutting inner was loaded in fab modules

.

.

.

.

.

.

.

.

The excess copper was peeled out, I knew i had wasted a lot of copper. But it thought it was quite unused in lab, it was worth trying

.

.

.

The output files obtained is as below:

.

.