SwinSID ATMEGA88

This bug exists in all SwinSID firmware versions and it is not realted to C64 board.

Hi

Im trying to make my own Micro SwinSid (Mega88 28pin) and i looked at the schematic and it shows buses where many wires travel together(not all connected together) Normally each wire has a name where it enters and exits the bus. Because there is no hint as to which wire is which in the bus I don't know what to do.
Usually a bus has a name like A0:A7 and each wire has a name like A3 or A4 or A5.

Im using Eagle Cad software.

Every wire has its name but they are not shown. Just right click on the wire on the schematic, open properties window and you will see what is the name.

Hello, Swinkels.
Which AVR can I use instead of mega88: will Mega168-20PU or 168A-PU work?

Also will it start with lower frequency oscillator? Just for testing purposes. 14.318 or 16 mhz for example

All i have with 168-20PU and 168A-PU is this tone when i'm touching reset pin. With or without oscillators. (tried 32, 24, 16, 14.318 Mhz)

I've not checked 100% all connections but I routed up the schematics provided for the Micro SwinSID and managed to produce the following single layer PCB.
Does anyone have any comments on the layout, possible issues for example?

urbancamo, very good!
Jus move filtering cap as close as possible to atmega vcc/gnd pins and add two holes for square oscillator.

Thanks for the comments. I understand about moving the capacitor, but I'm not sure about the oscillator comment - it's got four legs and four holes, but maybe I'm missing something? It should probably be moved to the other end of the board so that the oscillator signal isn't routed right round the board.

In the meantime I've attached a ZIP file and some images for the schematics and PCB layout. I've now verified the netlist against a previous design verified as working.
The ZIP file contains all the other attachments and DIPTrace Schematics and PCB layout files.

Here's a new version with the Crystal at the other end.

I'm not sure if firmware will run on ATMEGA168 but as far as i know the only difference is a flash rom size.
After every reset SwinSID generates 1KHz fading out test tone for 1s. Check your fuse bit settings and enable external oscillator mode.
The test tone should be heard at any clock frequency but with lower speed the test tone frequency will be also lower. To read data from C64 bus you need at least 20MHz.

Thanks, Swinkels and Manawyrm. Fuses are ok, one of 168's have started correctly with 1khz tone once but glitched few seconds later. I think they cant run at this frequency.

I've found and order Mega88PA @ ebay so now waiting for parcel. (working on Midibox StereoSwinSid module with cheap equal to quartz oscillator cirquit (74LS04 + Crystal) so I have to be completely confident in the MCU)

urbancamo, i'm talking about something like this

http://www.schickt.de/temp/swin3.png

There's two types of DIL packages so considering this will be great. Chinese suppliers often have one package type at photo and finaly you get another (TaydaElectronics for example)

Another question to Swinkels: Is there any comparision samples of SwinSID with DAC and NanoSwinsid? I'm interested in musical/synth aspect as you guessed. 8515 is hard to find, so should i stay with Mega88 or try luck with old version too?

I don't know, where you live, but there are serval supplieres for the ATmega 8515 and 8535. The ATmega 8515 is compatible to the old AT91S8515.
They are also available in PLCC Cases, so you can save space on the PCB.

Russia, which is banned by most sellers. And I don't wanna mess with PLCC PCB tracing, considering that there's finished DIP layout by nILS (mentioned above)
I'll find them. Just want to be sure that it worth.

I don't know. The DAC is quite rare AFAIK.

Quote from PeterSieg

@crasbe: Ich habe das Gefühl, du bist auf dem falschen Dampfer = alter SwinSID mit Atmega8515 und DAC. Hier ging es dem Kollegen aus RUS aber anscheinend um die ATmega88 Version..

Peter

Er hatte den ATmega8515 erwähnt im Vergleich zum ATmega88 und ob sie sich in der Klangqualität unterscheiden. Außerdem meinte er, dass die schwer zu finden sind.

Aber das ist OT.

crasbe

TDA1543 DAC is realy hard to find so I recommend to use ATMEGA88 which is easier to build and has reduced aliasing distortions thanks to higher samplerate and CPU speed.

[offtopic]They still available at ebay, I've bought a couple of 1543 here [/offtopic]

Thnx Swinkels, now everything is clear.