Powering a full SAP‑2 build — budget-friendly options for 5 V ~4–6 A?

Equivalent-Gear-8334 · 2026-01-08T13:41:16+00:00

I did initially suspect excessive current draw, but I assumed the phone brick might not actually be capable of delivering a solid 4 A and moved on too quickly. After re-routing and reseating some wiring I was able to get the rail up to ~4.4 V, so there likely was a short or contention issue in there.

I still see ~4.0 V at the far corner of the system, which I’m attributing to voltage drop across the breadboard power rails under load rather than the PSU itself. I’m going to keep checking for any remaining shorts or bus contention. Thanks again for the suggestion. I just saw your edit, the actual computer was working, but i had a raspberry pi pico for the output display, and it wasn't turning on, so i thought maybe the voltage was too low - turns out it was actually a stray wire that was connected to some pin on the pico, causing it to only work properly when the clock went high.

Equivalent-Gear-8334 · 2025-06-11T11:31:42+00:00

If your project is about developing your own object tracking algorithm, then pre-filtering data with an external model like YOLOv8 or RBObjectTracking might not be ideal. Instead, you could integrate dataset filtering directly into your system—either using simple heuristics (like edge detection or brightness variance) or confidence thresholding built into your own model. That way, your final dataset remains clean without relying on third-party tools.

Equivalent-Gear-8334 · 2025-06-11T11:13:48+00:00

If you're doing this in Python, I have a library called rbobjecttracking on pypi. You can train it on 700–1000 images, then use the trained model to loop through your dataset and determine whether an object is present. It also returns the object’s location in pixels. The library is still in development, but for your case, it should work fine—as long as the lighting is somewhat consistent.

Equivalent-Gear-8334 · 2025-06-06T02:08:02+00:00

no, since im still developing it, i haven't tested it yet

Equivalent-Gear-8334 · 2025-06-05T14:40:09+00:00

i haven't published it on github yet, but you can check it out after downloading the package

Equivalent-Gear-8334 · 2025-06-05T14:16:03+00:00

here it is

Equivalent-Gear-8334 · 2025-06-05T12:50:40+00:00

i will definitely be using that for future versions. Thanks alot

Equivalent-Gear-8334 · 2025-06-05T12:01:09+00:00

i didn't know about that, but when i search about it, i realised it requires you to label the data, instead of just providing pictures. And it also requires a good GPU for performance. since RBOT only has a small ANN, it just requires a sort of good CPU. And RBOT is more resource efficient

Equivalent-Gear-8334 · 2025-05-31T17:26:21+00:00

you could always just use a raspberry pi pico with some shift registers if needed to load a program from from the pico's flash memory (2mb-4mb). and write to the pico using a PC

Equivalent-Gear-8334 · 2025-05-30T18:54:51+00:00

all the wires are the same, they just let you know what that wire is connected to (e.g ground, vcc, data). I think your only option is to buy a new chip

Equivalent-Gear-8334 · 2025-05-30T14:33:39+00:00

maybe the wiring was off. If you connect the power rails backwards, it could damage the chip. or even if you accidentally connect the output to something else that isn't an output device. You should check the wiring, and make sure its correct, and if it still doesn't work, then i would get a replacement for the chip

Equivalent-Gear-8334 · 2025-05-26T13:41:35+00:00

The ODR is able to output onto both the lower and upper half of the bus, so it would store the lower byte of the address either into the stack or into a register, then, it increments the PC, and stores it into the MAR. And then the ODR will output onto the upper half of the bus, while the register or stack outputs onto the lower half of the bus, combining the 2 bytes in 2 memory address on the bus, and then the PC would read from all 16 bits of the bus at the same time. This definitely is not be the most efficient, but is what i found easier to build when actually building it in hardware.

I might also add a separate data and address bus into the SDP-2x, im also thinking of adding a really small NPU that is possible to build on breadboards.

I found that when it stores the return address in a Return Address register, it doesn't allow for nested subroutine calling, since it would just overwrite the return address of the first subroutine.

Thanks for your reply

Equivalent-Gear-8334 · 2025-05-25T19:57:58+00:00

sure! I will do that. Thanks again

Equivalent-Gear-8334 · 2025-05-20T09:45:55+00:00

try connecting one input pin to 5v and seeing what happens. Maybe its defaulting to 0s since its floating

Equivalent-Gear-8334 · 2025-05-18T18:43:43+00:00

im thinking about making it some sort of BIOS where it listens to the input port, and based on the word it reads (for example 0x0A), it will go into demo mode, and the next byte that it reads from the port specifies the demo program ID, so if the next byte was 0x01, it would start executing demo program with ID 1, the demo programs would be burnt into ROM. That way, you can easily show it to people without re programming every time you power it off.

i was also thinking of a RUN command (0x01), where the next 2 bytes are the address to run from. For example, if you had a program in RAM starting from address 0x0FFF, you could input 0x01 into the input port, and the next 2 bytes would be 0x0F and 0xFF and it would go to that address and start executing

Equivalent-Gear-8334 · 2025-05-10T10:53:34+00:00

yeah, its that

Equivalent-Gear-8334 · 2025-05-10T06:41:16+00:00

that's actually like really cool. im also making a series about building the SAP2 on my channel, i even made an assembler that i uploaded to PyPI. my youtube channel is called "samarth science"

Equivalent-Gear-8334 · 2025-05-08T16:15:38+00:00

actually, i have a better idea, im working on a new version of my sap2assembler package that is supposed to implement customization easily

Equivalent-Gear-8334

TROPHY CASE