C64Pico part 3

Last Updated or created 2024-05-01

Started working on C64Pico with Bigred

C64Pico Follow-up

Today we worked on this project again. (Bigred and me)

There were some problems we needed to fix since last time:

It was quite hard to get the correct parts.
Our display connector was only fitted with connection pins on the wrong side of the connector. (up/down)
So I bought a connector with both positions populated.
So we had to replace this hard to solder (40 pin) connector.
It was not clear what the orientation should be of the atmega328pb.
We looked at the pinout, and followed the VCC/GND. But these are also available of the opposite side of the chip. (We missed that)
Later, we saw a tiny line on the PCB, which showed the pin 1 placement.
So we had to remove and replace the chip.
When turning on the power, (with incorrect placement) probably fried R5 (10k resistor), on both our boards.
Had to replace those also.
Programming the atmega328pb was not easy, see below fixes.
Compiling the pico firmware resulted in a black screen.
Below the fixes I had to make to get the screen working.

Other things still to fix.

Bigreds screen.
atmega328p didn’t work for Bigred, so probably needs to replace with the pb version.
My battery controller is not charging.
See bottom of page
Some of my buttons are working. The pewpew and some of the cursor keys (not as I expect, there are some up/down issues)
And none of the other keys are working.

Some other things we noticed.

sdcard: remove partitions, format using mkfs.exfat
Create a c64 directory on this filesystem where you can put the d64 files!
0402 SMD is far too small for me.
There is enough room on the board to use 0805 for example.
Even THT is possible, there are only a few components.
Some components are TOO close together, removing a component resulted in other small parts disconnecting also.

My friend Bigred said: If I can see it, I can solder it.
But it is not easy. This probably keeps a lot of people from building it!

~~Below the diff from the source we got from:~~

UPDATE 20240501: We needed to clone the c64pico branch!

git clone -b c64pico https://github.com/silvervest/MCUME.git

Then it worked with the screen and keyboard!

Programming the atmega328pb using usbasp

To get your Arduino IDE up and running

Open the Arduino IDE.
Open the File > Preferences menu item.
Enter the following URL in Additional Boards Manager URLs:https://mcudude.github.io/MiniCore/package_MCUdude_MiniCore_index.json
Open the Tools > Board > Boards Manager… menu item.
Wait for the platform indexes to finish downloading.
Scroll down until you see the MiniCore entry and click on it.
Click Install.
After installation is complete close the Boards Manager window.

Above settings worked for me, maybe you can also try Programmer: usbasp (slow)

First install the bootloader.

When compiling the keyboard program of silvervest, you can find “Upload using programmer” in the Sketch menu!
(https://github.com/silvervest/c64pico/tree/master/keyboard)

CHARGING using BQ24230RGTT

Maybe I’ve got a problem with the ground plating of the charger.
Also very hard to solder the sides!

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