Embedded programming 2.0

individual asiignment

Read a microcontroller datasheet and program your board to do something

group assignment

compare the performances and developemnet of diferent workflows

you can go here to see what i did on this week group assignment

Disclaimer

i've pushed a test on the final board programmed

Test on the morse code

Disclaimer

Fabacademy 2020 and 2021 efforts

also all of the links can be found under "links and references"

this assignment has various steps

Disclaimer

I use a Windows 10 based system the (flashing commands and general workflow of installation may vary for another OS)

for more info about the instalation of edbg and openOCD for to

Read a datasheet of an MCU

i choose to do my very own version of the samdino made by adrian torres from fablab leon.

altough he made a terrifyc job i´d like to make use of the THT components i have at my disposal at fablab queretaro.

i talk more about this design on electronics design week tough.

So i'm up with the task to design and fabricate another homade "arduino" bootleg

i choose adrian's samdino version because of his documentation it's very clear and straight fordward.

so the first on the list was to download the datasheet and try to understand it.

HERE you can download the same datasheet

the first thing i noticed is that has 14 pins

then it has 16KB of flash memory

and unlike the atmega328p i used before this MCU runs on 3.3v.

mcu pinout from the datasheet

mcu pinout from adrian's samdino page

it has spi,I2C USART comunications protocols compatibility built in

Design a board.

HERE you can check the assignment on electronics design i did

also HERE you can download the EAGlE files on this board

Flash the board

take out the board from the cnc

weed it,clean it and probe it with the multimeter

Stuff it and probe it once again with the multimeter

I choose to use an adapter in order to flash the memory out of the samd11c, because i have to do this step once and then the traces on the board become useless.

this is the adapter i used to flashe the board

HERE you can check the specs

HERE you can download the eagle footprint to use it on your own designs

this is how i conected the swd programmer

this is my setup

on a fresh windows CMD terminal navigate to the file were the edbg and openocd is stored check electronics production to see how to

download the binary for a generic SAMD11C chip from HERE and place it on the same directory as the edbg,openocd and free-dap binary file

and then type edbg-windows-r24.exe -ebpv -t samd11 -f sam_ba_SAMD11C14A.bin

on Windows 10 when you first conect the board pops up a meesage like this installing the proper driver for the device

Install the samd11c board on arduino IDE

https://www.mattairtech.com/software/arduino/package_MattairTech_index.json

you need to copy this URL and paste it on the arduino IDE

You can do it under file/preferences

Only then you'll be able to install the MattairTech core boards

you can do it under tools/board/board manager

Upload a sketch

open the blink example and use it to turn on/off the led on digital pin 2

HERE you can download my sketch

Select you com port before you upload the sketch

on the lower half of the IDE GUI you should get a message like this one

Also i did a button testing on this week

this is the code i use

HEREas always you can get the file .ino from here or in the "links and reference" section

this is a simple counter and push button and a LED just to test the board

an this is the video

Morse code test

as my global instructor said the blinking of a led is too simple you need to code a little more complex

so i decided to do a morse code translator because i think it's simple enough to be using the power supply on the usb of a laptop and not burning it.

The principle of the morse code is really simple each letter of the alphabet get translated into discrete pulses of light or sound divided by silences or time lapses where not light or sound is emited by the source.

below it's a scheme of this letters translated into dots and dashes separated by blank spaces of silence.

this picture i took it from a tutorial HERE

so i went into the internet for some ideas and found this excelent tutorial on how to use an MCU as a morse code translator using the serial monitor terminal

the article does not authors a person but an "editorial team"

device plus

so this is an excelent resource to find diferent code examples and well explained.

for a noob like myself.

i'll try my best to explain how it works on the comments of the .txt and .ino files

so this is a sketch to translate serial monitor into morse code using a buzzer

setup

just 3 wires 5v, gnd and signal comming from pin 2 on my board

code

for this code i use one pin as output(specifically pin 2 on my board).

i use a variable to set the default tone of the buzzer (1000)

a default time unit that will be used to muliply or divide wether if it is a dot (2 times the time unit),dash (4 times the time unit) letter pause (3 times the time unit) or a word pause (7 times the time unit)

because i'm only using nested IF statements and functions. i do not need to call for any library

if (input == 'a' || input == 'A') if the variable holds the char "a" or "A" then calls the function 1A()

and so on

then the function 1A() it's called later outside the void loop

within void 1A() and it calls specific function in a specific order to make the letter

for the example of the caracter A or a

it is dot followed by a dash and then a letter pause

so the dot function is

arduino function called tone whch need to be specified the pin of the output,the note will be emiting and the time will be emiting it

tone(buzzer,note,timeUnit);

then after the tone the delay of the time unit that represent the letter pause

then the dash function gets called and do it's job and then the letter pause function gets called and do it's job.

this is just for the letter A

also all of the lines are commented on the text file below.

everything that follows after // is a comment and is just for debugging purpouses

this is the code on this test

*ino File

Back to index

Conclusions

comparing this board with the old attiny gen 44/84/45/85 and so. This workflow is a lot more simpler and straight fordward.

i would never have done it with out adrian's documentation.

Links and references

Adrian's Samdino page

blink file for the luisino

Button INO file