Schematic availability in poor shape?

[mr.chris.styles]

Hi All,

I have started designing some expansion hardware for Raspberry Pi 2 Model B,and I am struggling to find complete schematics that match what I have.

I have viewed this page :

https://www.raspberrypi.org/documentati ... /README.md

I have also spent some time with Google, and correlating what I have in front of me (given what is says on the silkscreen) to a set of schematics is a challenge.

The board i have says "Raspberry Pi 2 Model B v1.1" on the silkscreen.

When I look at the PWR and ACT LEDS on my board, they are both driven by a FET.

When I look at the "Model B+ Revision 1.2" schematics, PWR is driven by a FET, but there is only one sheet, and it is far from complete.

All the other schematics have the LEDs driven directly, and so are clearly not right.

Can someone at RPi look into this, and publish the full schematics for each version, and make it clear which match with which silkscreen legend.

Cheers,
Chris

[jamesh]

Hi All,

I have started designing some expansion hardware for Raspberry Pi 2 Model B,and I am struggling to find complete schematics that match what I have.

I have viewed this page :

https://www.raspberrypi.org/documentati ... /README.md

I have also spent some time with Google, and correlating what I have in front of me (given what is says on the silkscreen) to a set of schematics is a challenge.

The board i have says "Raspberry Pi 2 Model B v1.1" on the silkscreen.

When I look at the PWR and ACT LEDS on my board, they are both driven by a FET.

When I look at the "Model B+ Revision 1.2" schematics, PWR is driven by a FET, but there is only one sheet, and it is far from complete.

All the other schematics have the LEDs driven directly, and so are clearly not right.

Can someone at RPi look into this, and publish the full schematics for each version, and make it clear which match with which silkscreen legend.

Cheers,
Chris

Pi2 schematics have never been released. The Pi1B+ schematics should be good enough for what you want to do as the GPIO's are the same. Also, check the HAT specifications.

[GTR2Fan]

All the other schematics have the LEDs driven directly, and so are clearly not right.

Why is this clearly not right? This certainly appears to be the case on the early Model B that's sitting right in front of me. The Pi2B also sitting here has the FETs of which you speak, as do the B+ and Pi3B I believe.

I'd be interested to know in what way this is relevant to you when you'll presumably be using the GPIO headers exclusively anyway which are well documented for all models. Please do tell! I'm incredibly nosey.

[Heater]

Why do you need the schematics to create an add on for the Pi?

It's probably better not to design around the schematics. Or the details of the board layout. You never know what might change ore move around in future revisions.

Stick to the interfaces provided.

[mr.chris.styles]

Its clearly not right because the fragment of the schematics I have doesn't match whats on the board. If the board has FETs driving the LED, and the schematics don't, they aren't the schematics of that board!

For the schematics that *do* match, there is only one page.

[mr.chris.styles]

Why do you need the schematics to create an add on for the Pi?

So I can see exactly what is wired where!

I will be using the 40 pin expansion header, but want to see exactly what is wired where. There is a chance I want to use features of the BCM, so I'll need to look at its datasheet, to figure out what BCM pins go to which header pin, and therefore which alternate features I have access to.

[gregeric]

All the GPIOs on the 40-pin header go directly to the relevant ball on the 2835/6/7. Only exceptions are with I2C, there are ~3k3 pull-ups on SDA SCK as you'd expect (this applies to GPIO2, GPIO3, ID_SD, ID_SC).

A good reference for alt functions is http://elinux.org/RPi_BCM2835_GPIOs, and of course the bundled "raspi-gpio get" etc command.

[jdb]

Why do you need the schematics to create an add on for the Pi?

So I can see exactly what is wired where!

I will be using the 40 pin expansion header, but want to see exactly what is wired where. There is a chance I want to use features of the BCM, so I'll need to look at its datasheet, to figure out what BCM pins go to which header pin, and therefore which alternate features I have access to.

GPIOs 0-27 map on to pins on the GPIO header, some of them have been fitted with 1.8k pull-ups.

Read this:

https://www.raspberrypi.org/documentati ... matics.pdf

The GPIO header is unchanged between B+/A+/B2/B3.

Ta-da! You have a complete description of the I/O signals available to you.