bwack/c64-saver-bwack

c64-saver-bwack's Issues

voltage from 9VAC too high for the arduino pro micro's regulator (C64 Saver 2 addon)

Unfortunately the board needs a regulator after the rectification of 9VAC. After rectification, and no load, the DC voltage is around 15V. The RAW pin of the pro micro is 12V max.

With a 9 or 10V regulator, the power dissipation of the regulators are split equally.

Needs more pullup on Q1 drain

C64 Saver v2.2

Add a resistor between 5V and Q1 drain. 4k7 worked fine.
Remove R5 (redundant).

Removed capacistor

Hi bwack
The capacitor you removed to make room for resistors, what was the function of that capacitor?
Regards
sfk

BOM?

Hello! First of all thank you for providing this. It's a really great piece of equipment and I'm excited to try it out on my "new to me" c64 =)

I'm a very experienced electronic hobbyist- but building a board with Gerber files and parts is really new to me. Do you have an actual part list somewhere? Because I see something called a kessler number which doesn't seem to match up with any of my vendors for parts. Let's say for C1. It shows it is a 47UF cap that is CP_Radial_D6.3mm_P2.50mm....am I just going to mouser and trying to find caps that are round and the right size for the uF? There are so many millions of parts that the options are a bit confusing for me.

Any help would be great appreciated. Thank you =)

U7 wrong pin configuration addon board 1.3

U7 5V regulator got very hot and was therefor changed (see changelog) four years ago. Someone requested and got gerbers from me a year later. I had stopped working on it. I never got feedback about this until last thursday.
Pull requests welcome (just kidding). I will update when this 1.3 has been tested and all bugs have been ruled out.

Q1 pinout mismatch

C64 Saver v2.2

Might just be the 2n7000 I have here. I don't remember what transistor I initially tested. Q1 is a logic level NMOS transistor. 2n7000 has pinout (SGD) 1,2,3 while the board has 2,1,3.
I will just flip pin and two for now on the prototype.

Gerber for addon board not latest version

"If you are looking for Gerbers, click the releases tab. There you will find a zip file of Gerber for each release."
Clicking on Releases only nets AddonBoard1_2_gerber.zip.
Has v1.3 not been released as Gerber yet?

U4,U5 EL1012 Discontinued

As the title states, the part as referred to in the BoM for U4, U5 as https://www.distrelec.biz/en/optocoupler-sop-4l-80-everlight-electronics-el1012-ta-vg/p/11049956 is discontinued, and not available in North America any longer.
The schematic has parts U4, U5 referred to as TLP291. Any TLP291 available at Digikey is a 4-SOIC (0.179", 4.55mm Width) that is NOT the same footprint as that on the PCB for the addon board.
Can you suggest any alternatives that fit the parameters of the EL1012 that is readily available and are the same package and size?

BOM does not match current version

As in topic - BOM file is version 2.3 while current version of the saver is 2.4

No cut-off for 9VAC power line

Since C64 uses 9VAC to power the SID chip, it is advisable for the 9V AC power line to be cut-off in case of 5V overvoltage as well. Otherwise the SID chip remains powered, while the rest of the computer is not.

The 5V section draws power through the shunt resistor

Current draw from the addon board shows up in the shuntvoltage readings.
To fix this the voltage regulator input must be moved from VIN- to VIN+.

C64 Saver parts

Since the IRF9332PBF transistor seems not to be manufactured anymore and is difficult to buy, which transistor would you recommend as a replacement for the IRF9332PBF?

pinout changed.

pinout on addon board changed to fit the pro micro on the board. Change pinout on the base board accordingly. The 9VAC lines should have more pins also.

SDA and SCL are mixed up

addon board v1.1: SDA and SCL mixed up

Soldered board (2.6 throughhole) with new mosfet not working =/

Hey Fellas- I got my board together and tried a test for the first time last night. I'm not getting any indication of power on the board.
I made the two cuts, installed a IPD068P, changed the zener location, and hooked up the LED but nothing. I had the hardest time getting the two small transistors soldered(Q1, U1) I'm wondering if I possibly heat damaged them?

Any troubleshooting steps I can follow?

I had the input hooked my bench power supply at 5V- I had a 10Watt, 5 ohm resistor on the output for a load. Is the a proper method to test it? If no- how would I better test the unit?

3D model of C1 shown the wrong way

addon board 1.1 in the readme

High voltage drop over the power MOSFET

I measure V_DS=200mV at V_GS= -5V and I=1.2A.
We would like the voltage drop over the C64 Saver to be as low as possible, in case someone is using PSU with voltage on the low side of the VDD tolerance (which is 5V +-0.25 V ?)..

In Saver 1.3 I did a lot of testing for voltage drop over the whole circuit and was quite happy with it with using IRF9332. It promised Rds(on)=28.1 mOhms at V_GS=-4.5V. The C64 draws about 0.8A. For 1A draw, we would hve 30mV drop or less. Unfortunately this has a different package than what I'm using now.

Then when I made the Saver 2 I selected a part that would give similar results. So why this high voltage drop now ?
Has the part changed ? Are there variations to the IRF5305 ?
Nobody has complained about this. I guess it works well for those who use it, but the thing is, I built myself a PSU after starting this project, and haven't been using it much myself, but when I have used it, It has been working fine. Also I haven't touch this project for three years.

This needs more investigation, and lets continue to figure out what happened, and find a replacement part for this mosfet.
I would like to see a P-Channel mosfet, V_DS max 30V, R_DS(on)<=30mOhm @ V_GS=-4.5V. Imax is not so important because it is usually very high for these low resistance devices.

SENSE_VAC feeds in on non ADC input

Suggest swapping it with SENSE_VAC PB1 with HOLD_ PB4. After swapping, check that MISO still works by programming the device. MISO is used for programming. HOLD_ is pulled thowards ground through the optocoupler diode. Suggest moveing HOLD to cathod and attach anode to 5V. Then HOLD_ is pulled thowards 5V which is probably better for SPI.

Errors on the addon board

Debugging the addon board 1.0 pcba

R10 in C64 Saver SMD 2.5

Hi,
I'm referring to the 2.5 SMD version of the saver. Why is R10 (3k3) directly connected to 5V_SAFE, while on the PCB it's routed to positive pin of LED2 but merged with the 5V_SAVE plane? Negative pin of LED2 is connected through R11 (3k3) to GND. Is this an issue? If not, can you please explain?

ATtiny wrong footprint

It's not SO-8, but two mm wider or so.

2.4 Throughhole C2

Thank you for creating this project. I'm in the middle of the build of V2.4 Throughhole, and I think C2 in the BOM might be an error. I don't see where this fits into the actual circuit/circuit board. Is C2 needed/preferred somewhere?

Through hole Zener Diode Sizing

Hey fellas. Just getting around to putting this thing together. The BOM for through hole zenners isn't very clear so I went to SMD bom and found the part number that was provided there. Then I bought a zener based on that. I only hesitate because this one is much smaller in size than the markings on the board. Both are showing .5watts 6.8v 2% so hoping I'm OK.

What do you think?

The part I bought: https://www.mouser.com/ProductDetail/Vishay-Semiconductors/BZX55B6V8-TR?qs=WLTup5mM6hj4D2ZUwZwaKA%3D%3D

The part I referenced from the SMD bom: https://www.mouser.com/ProductDetail/Taiwan-Semiconductor/BZY55B6V8-RBG?qs=mAH9sUMRCtuk9q3vqhCMbg%3D%3D

Thank you!!

Code locks up when using the ssd1306 and ina216 libraries together

@discoHR From what I remember when debugging this I saw that after the sd1306 library had the i2c and the ina216 was taking over, the code got stuck in a wait for high or wait for low call.. The libraries works fine on their own. Find out why one module screws up for the other.

Btw this is why I have included the usi_i2c_master library. This library is from the nunchuk64 project. From what I saw, the sd1306 library is a bitbanging library while the other two use the TWI module.

PCB dimensions

Hello there,
Apologies if this is a silly question or not the right place where to ask but I am a bit lost.

I wanted to have some C64saver v2.4 through hole PCBs manufactured but the various manufacturers are asking me the PCB size. Could you please point me to the right direction where to find that information?

Thanks a lot!

A signal is interfering with the RESET pin

When voltage is brought down below the threshold, the display stops updating.
#OVERVOLTAGE is connected to the #RESET input of the MCU. We need the reset for the ISP to work. Here is a workaround: voltagedivider + adc !
https://electronics.stackexchange.com/questions/195146/use-the-reset-pin-on-attiny85-as-input-with-voltage-divider

addon board 1.0

Images not showing

Hi,great project!

Just wanted to let you know that the images for "The C64 Saver 2 (base board)" in the Wiki are not showing, -the links are broken.
brg
Magnus

Q2 reversed

C64 Saver v2.2

Body diode pointing the wrong way. Pinout is correct though between schematic and datasheet for irfr5305.

Replace MCP1700 with higher max input voltage

U7 MCP1700 not handling over-voltage condition. Get MCP1754ST-5002E/CB
https://www.elfadistrelec.no/no/ldo-spenningsregulator-sot-23a-microchip-mcp1754st-5002e-cb/p/17386686

addon board 1.0

330K Resistor

Hi, not really an issue but I am in the UK and really strugging to get hold of a 04W 330K resistor, I can get hold of 300K 0.4W will this be Ok. Sorry for the noob question.

Brendan

Firmware for the addon board

Programming the ATTiny85

We will use the Ardino IDE or avr-gcc toolchain.
For OLED display and ATTiny we will base our code on this project:

1. http://cyaninfinite.com/tutorials/interfacing-a-i2c-0-96-oled-display-with-attiny85/ or
2. https://www.instructables.com/id/ATTiny85-connects-to-I2C-OLED-display-Great-Things/

Number 2. seems the most interesting.

The MCU will be connecting with these devices over I2C

• INA219 current and voltage measurement (5V)
• ACS712 current sensor (halleffect, AC current)
• OLED 128x32 SSD1306

The 9VAC is fed in on a ADC pin, and is shared with the button. If the ADC reads around 0, then the button is pressed.

Resistor sizes

C64 Saver v2.1 and 2.2:
The pcb has footprints for resistors DIN0207 3.6x1.6mm (main part x dia).
I have the 3.7x1.6 mm throughole resistors, and smaller than that are hard to get. They fit if you bend the legs as close as you can to the resistor.
The Kicad library does not have any sizer larger. if you're bored you can change the footprint by widening the distance between the holes by say 0.3mm.

Optimizing gate voltage for Q1

I have built the Saver 2.4 Throughole but the output voltage was not disconnected at overvoltage.
I meassured the output voltage of U1 (TL431) at overvoltage with 1,8V. The gate voltage of Q1 (2N7000) was after the divider 33k/82k at about 1.3V.
According to the Datasheet of the 2N7000 the Gate-Threshold Voltage of is between 0.8 an 3V
I did not find the the max output voltage of U1 (TL431) in the datasheet. I think this is about 2V.
I think the values of the divider resistors should be changed. I changed the 82k to a 33k resistor this works with my parts.
Maybe further investigation is necessary.

Vth of Q1 2N7000 too low

I noticed this while ordering new 2N7002 nmos transistors. They measure Vgs threshold 1.9V. The other batch I have are 2N7000 and measure 2.5V. The minimum value shown in the datasheets are below 1V (!).

The problem is the TL431. Its output is also its power supply. The output will therefor not go below 1.8-2V.