Tuesday, 24 July 2018

BAW!! #2 TINYMCU

I have always love Micro-controllers (MCUs') I find the fascinating the idea that there is a complete computer on one thin slice of silicone, including RAM, storage and peripherals. And these device can be small super small in fact.

On MCU I have had my eye on for a while is the Atmel Attiny10. Well I'll correct myself its now the Microchip Attiny10 as Atmel where bought out by Microchip a couple of years ago.

Name
Value
Program Memory Type
Flash
Program Memory Size (KB)
1
CPU Speed (MIPS/DMIPS)
12
SRAM Bytes
32
Capture/Compare/PWM Peripherals
1 Input Capture, 1 CCP, 2PWM
Timers
1 x 16-bit
Number of Comparators
1
Temperature Range (C)
-40 to 125
Operating Voltage Range (V)
1.8 to 5.5
Pin Count
6
Source taken from Microchip.com



Though after starting this project I discovered the PIC10F320 and PIC10F322 have the same package and pint layout. Well at least for the SOT23-6 package. 



In the schematic I have decided to add as much debug/experimenting hardware as possible so to do this I have: 
  • Added a jumper to enable the pull-up resistor for the reset pin (incase i would like to use the 4th IO line)
  • Current limiting resistors on all the IO lines ( Just good practise to avoid drawing too much current from such a tiny device each IO allows a maximum of 40mA per pin)
  • Indicator LED's (so I can get instant feedback on the pin status)
  • Jumpers to enable and disable LED's ( I have made these pin jumpers so I can use the raw pins if needed for the ADC and CLK lines if needed.)
  • Programming Header (make life easy)
  • Power indicator LED (Got to make sure there is life :) )
  • No Voltage regulator ( i want to be able to set my own voltages I would love to see how the device performs at the low end of its voltage range)


Don't forget all schematics and design files can be found at https://github.com/rabid-inventor/board-a-week  


Once I started to route the traces I discovered that the board may be able to have a single sided design. 

I rotated the MCU to try an make routing easier.


It was all going so well when I got to one last airwire. BUT:

Unfortunately the board was getting messier and messier just to make it single sided (see the bottom left corner of the board), and to get any further meant making the board size bigger and routing more around the edge. I was unfortunately time to admit defeat and route the board 2 layer.

20 mins later I had it all routed.



The design is now finished and ready to be sent for production. I'm really looking forward to having this one made, and be able to see what is possible with this tiny MCU.

I have also added a CC-BY commons licence please feel free to take a look and comment. Let me know what you think.




Thursday, 19 July 2018

BAW!! #1 XOR

Hi everyone its the first week of Boards A Week and i am kind of excited to get underway.

The first board I want to make is an Exclusive OR (XOR) gate, and XOR gate is one of the basic logic blocks used in electronic design which normal comes as an IC package containing multiple gates like MC14070B. The truth table below shows how it operates.

Truth Table


Input A Input B Output C
0 0 0
1 0 1
0 1 1
1 1 0

The reasons I wanted to design this board is to help my understanding of how complementary logic works by using discreet components, so using resistors and FETs.




The full design files can be found at http://github.com/rabid-inventor/board-a-week. I have tried to include all the source material used, including the fonts I have used for creating the silk screen.  



I'm really pleased with how this little board looks and can't wait to have it made to see if my idea works. 

I can't wait to do more of these in the passive blocks in the future. 





Wednesday, 11 July 2018

Board a week !!!!!

One of the hardest things as a maker is to keep motivated to be able to push your skills forward, and being able to make all the mistakes in the world so that you can learn from them.

So to answer this never ending problem and to improve my PCB design and understanding of electronics is I will design one board a week and share it.



These are the rules I'm setting for myself.
  • For a board to be complete it has to be fully routed (which is where all the traces are liked)
  • The DRC and ERC are complete. ( these are the checking tools in PCB design software which help the PCB designer to check if the design and electrical layouts are sound)
  • Silkscreen labels complete.
  • To try some alternative CAD software instead of Autodesk Eagle which i'm reasonably used to.
  • Publish to GIT hub as Open Source Hardware 
I don't intend on having every design made of in some cases even populated but I'm going to try and choose one design from each month to send to production.

I'll be doing a blog post each week, and trying to explain some of my design decisions and some of the methods I have tried to use.

I hope you enjoy this journey with me.

Monday, 9 July 2018

New Beginnings

Well what can I say..

Long time no post doesn't really cut it so much.

But here I am again starting to get back into the swing of writing content :)

So let bring you up to date:
  • I no longer have the Shed that I made a few videos in I miss it but times have to move on.
  • I still run a PCB assembly at Pimoroni Ltd. in Sheffield which is still an amazing mix of fun, blood, sweat and tears.
  • I have really been practising coding in C, C++ and python.
  • Trying to get to grips with Bluetooth ( A big complicated beast).

New things for the future:

As normal time is never on my side . I really want to be more focused in what skills i'm improving for myself. The 2 improvements i want to make over the coming year are PCB design and embedded programming.


I have a couple of ideas to keep me motivated, I'll keep you posted.