Individual assignment

Read the datasheet for the microcontroller you are programming
Program the board you have made to do something, with as many different programming languages and programming environments as possible.

Two weeks ago I got to program the board produced with the attiny45, this week I am giving a go at the attiny1614 to see if I could use it for my final project.

Here I tried to go through the datasheet...

The block diagram below, explains how the microcontroller´s different elements inside interact between each other. We can also see, although I barely understand it, how the programmable memory in System is made. how it is mapped, how much space it holds, how that memory can be divided and where the detailed documentation/description on how to proceed to flash the memory can be found.

I am using Fusion 360 to design it, although I did try Kicad but the interface did not agree with me, I need to Learn the software and find the libraries...I´ll get back to it further down the line.

I found the attiny1614 symbole and footprint here as it was not in any of the libraries I had.

And I found the pin out in the datasheet...

I am also looking at the motors, I would like to use for my final project and how to include one or two (x4) in this Board. I followed this tutorial, advized by Adrian and ckecked the datasheet in order to figure out the resistors values needed to drop the voltage.

Using a step-down circuit, voltage/resistive divider, we can get from 5v to 3.3v.

Using this formula, I will use, as in the tutorial for handiness and because I have those, x3 10k resistors, we get a voltage of 3.3v witch I guess should be fine.

I tested it with the 5v power from an arduino.

For the design, Adrian advised me and explains here, I am using the 3 pinned version of the UPDI to avoid the need for 2 FTDI to programm my board.

That means that I need to add a pin on my board (VCC)...

Here I made a mistake, just finishing to mill the board...I did not connect the motor´s pins to ground but to VCC instead....

I also realized that I actually need to manually save changes by pushing "View 3d PCB" so that the very last changes are updated in all the projects documents...More about it here.

Making sure everything is synched this time...Here is the last schematic and traces, I added conection pads to solder the motors (J2, J3, J4 and J5) with their correcponding resistors, a switch (button) and an LED.

The files (.svg) for the TRACES and the SHAPE

And the 3 pinned UPDI

The files (.svg)

I am trying to program in the arduino IDE. to do that I am following Adrian´s tutorial (same as above). I need to add this URL (http://drazzy.com/package_drazzy.com_index.json) by SpenceKonde to the list in the board manager and install the "megaTinyCore by Spence Konde" board library.

Select: Board attiny1614, chip attiny1614, clock 20MHz, select port and programmer Serial port and 4.7k (pyupdi style).

I am connecting the board with the UPDI 3 pins with jumper cables (making sure to connect to the right pins on the board).

Here is when it gets interesting, my first mistake was to use the physical pin numbers (stated on the datasheet) instead of the names used when using the arduino IDE to program it. In my case I used pin5 instead of pin3 for the LED

The trouble is that even with that mistake in mind, If I load the program with the wrong pin, the LED still blinks, with very low power voltage (1.8vwhen I measure it with the multimeter), but it blinks...

I have check all the continuity and solder points, I also cleaned the board with nail varnish remover (low % of acetone). Now, I can not seem to be able to replicate the last state...and when I program the "blink" example on any of the pins used, the program loads successfully and the LED blinks normally.

The problem with the "blink" test and the pins used for the LED, comes from the actual program, where I have to asign the pin I want to use as OUTPUT, not only as a "constant", I also need to replace the LED_INBUILT for leppin.

Still no luck with the motors so I am removing them...

When I load the "button" example, it works perfectly and the LED works with its designated pin...

If I assign one of the pins used for the motor instead, I do get 3.3v at the pads with the multimeter (this works for all of them) which is a good sign.

but as soon as I reconnect a motor, the 3.3v disappear, same for all the pins

I am testing everything again with the arduino with the blink code, this time without the "voltage divider", I think the motor are my problem because I get the same issue programing the arduino with the "blink" test. When there is no motor, I get 3.3v, if I connect the motor, no 3.3v.

Without the voltage divider

So I need to figure out the current used for theses motors but at first sight, it looks like it should work with 5v....

Looking at a different datasheet, I can clearly see that at least 85mA is needed to start the motor and 75mA to run.

Further more, it looks like it is not a good idea to run the motors either on 5v or from the I/O pins as the motors will draw far too much current...

So in my next step, I will design a new board with this configuration in mind: resistor/transitor/diode. More on that in Project development page.