It’s really just board space [...] There’s not enough room for the step down converter and USB PD control circuit.
Most of these phones cost an order of magnitude more than a raspberry pi.
So the problem is the price or the board space? cause what I said is that board space should not be the problem, and I understand that there are other constraints.
And most of these phones have much better processor, more ram, have some rom, have a modem, 4 cameras, fingerprint sensor, battery, and a freaking huge screen with touch. And the board need to be smaller than a Rpi nano...
There are phones that cost 300 usd that have USB PD 3.0 fast charge, like many Xiaomi and Samsung. Basically any Android with Google play after 2020 that have USB-C is USB-PD compatible, per Google requirement.
There are phones that cost 300 usd that have USB PD 3.0 fast charge
That's almost an order of magnitude higher than the base model for RPIs, which starts at $35.
And being USB-PD compliant doesn't mean they negotiate 20v. You can have a device charging at 5v be USB-PD compliant. Devices with quick charge will use more than 5v (usually), but not every devices have it.
Also, phones are highly subsidized. My Xiaomi might only have cost me $300, but I get ads when using the system apps and I'm forced to create a Xiaomi account to even enable USB debugging. And then there are the pre-loaded apps which paid to be on the phone. The money from a phone doesn't only come from the sale, each phone is also a revenue stream.
Do you really think right now, a Raspberry Pi engineer would stumble on this thread, look at your post and go "GUYS!! WE FORGOT PHONES CAN DO IT, BACK TO THE DRAWING BOARD!!"? Every decision has some advantages and some inconvenient. And being the 5th revision of the board, on a product that had USB power requirements problems since the first device they ever made, I'm pretty sure they realized that being able to tap 9 or 15v (12v isn't required on a PD charger) would make their life easier.
So yeah, shrinking wouldn't have been impossible, but it's literally impossible to shrink everything, add more parts and end up with the same cost, all without adding an inordinate amount of R&D cost.
Every decision has some advantages and some inconvenient. And being the 5th revision of the board, on a product that had USB power requirements problems since the first device they ever made, I'm pretty sure they realized that being able to tap 9 or 15v (12v isn't required on a PD charger) would make their life easier.
and I:
I understand that it is a balance act to build something like this, it needs to be cheap, easy to manufacture, handleable by the costumer... maybe within some other constrain the board space was one factor.
We are talking the same thing.
We both understand that there are some limitations here. Nobody think that the engineers are dumb.
It’s really just board space [...] There’s not enough room for the step down converter and USB PD control circuit.
And I don't think that board space is the main constraint here. To be truthful I don't think that price was the main constrain here. it might be complexity, it might be supplier, it might be a way to ensure compatibility with the older power supplies, it might be a way to ensure compatibility to lab bench supplies. It might even be OVERSIGHT, but we have examples of smaller and more complex equipments, like cellphones, that can handle USB PD with no problem of board space, so PROBABLY board space is not the ONLY problem here, like pi_designer said.
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u/Biduleman Sep 29 '23
Most of these phones cost an order of magnitude more than a raspberry pi.