GPIO Ports - which ones are used

[Seanhump]

Hi again ...

As I've mentioned on one of my previous posts, I'm incorporating my PAW and power brick into a single 'carry-on' style enclosure.

Most of the bits are either here or on the way (Christmas post means I probably wont get this finished til the new year)  - all I'm doing is fitting everything neatly into a 190 x 140 x 30 Hammond instrument enclosure, using shorter cables where necessary for the power supply etc, shortening the lead from the GPS Mouse so it'll sit on top of the case and eternally mounting the antennas (ADSB one replaced with the NooElec one) and extending the cables with short RG316 pigtails in the enclosure.

This got me thinking about a power switch for the PAW - more searching led me to a post detailing that the software is in Read Only mode for most of the time (so the whole shutting down the Pi correctly isn't an issue) so I figured I could just keep the USB sockets on the power brick visible / available through a suitable hole in the case and just connect the PAW power by plugging in .. V1 of the case is being put together like this - the added benefit being that I can use the second USB port on the power brick to charge / power something else if I get caught short.

I'll post pics when I've got most of the rest of the parts here ...

The real Q on this post is about this MODMYPI LTD MMP-0045 UPS PIco I2C Control, Power Supply HAT for Raspberry Pi from here https://uk.rs-online.com/web/p/power-management-development-kits/1270208/?cm_mmc=UK-PPC-DS3A-_-google-_-DSA_UK_EN_Semiconductors-_-Power+Management+Development+Kits-_-DYNAMIC+SEARCH+ADS&matchtype=b&gclid=Cj0KCQiA9_LRBRDZARIsAAcLXje8zFQy8kxZTGOVj5pAo5iWmeFNUbPVB9-SNTdaEzNdeR45_9zy_9kaAkb7EALw_wcB&gclsrc=aw.ds

I stumbled across this whilst looking for power switch solutions and it seemed like a handy addon, especially as further reading of the specs details the fact that larger capacity batteries can be added (up to 8000mah) which should power the PAW for a considerable amount of time.

So the question is - which GPIO ports does the radio bridge use .? I'd like to check to make sure theres no conflict with the Pico board. (It's stackable and will fit in the case I'm using ...)

And from the other side, I've enquired via the ModMyPi forum what features are available at the hardware only level , just in case there are any issues installing the required software and messing up the PAW install ... There's not a great deal to add though ...

Thanks in advance

PS - I've been in the IT game for the thick end of 30 years now and am more than happy at the command line, though this is my first Pi - I kind of didn't bother with them when they first came out ...

Just a thought as it seems like a neat solution
 

[Admin]

Hi Sean,

We (currently) use the SPI interface, the I2C interface the Serial RX/TX and 3 further GPIO, which I cannot recall what they are - I think the bigger issue, is that, there is always the potential that we may use more of the GPIO in future revisions if required.
In fact we did bond out many of the GPIO pins to through plated holes on the PCB for easy customisation


Thx
Lee

[Seanhump]

Thanks Lee

I'll dig out the datasheet from the RS website and see what's used by the Pico ...

So far , it looks like it shares the I2C interface

It's no biggie if it's not compatible ....

Cheers
Sean

[rogellis]

.
I have likewise made a unified case for the PAW, as per the enclosed pic.  The standard PAW would not survive in the back of a glider, along with coats, parachute covers, and lunch, so it required robustification.  I have also enclosed a dc converter, amp and speaker in the box.

The first unit used a deconstructed Anker car dc converter, while the second one used this unit (below).  It is bigger than the Anker, and not as neat, but does not have to be deconstructed and does not need huge USB connectors.  If you can find a smaller unit, with at least 3 amps and low RF leakage, I would be grateful.

DC converter.
https://www.amazon.co.uk/gp/product/B01MT7JIWI

This PAW unit was producing some static on the speaker, so I changed back to the Anker converter, and that was producing noise too.  So this is just a noisy PAW for some reason.  The pulsating static seems to be coincident with the LED lights, and shielding the amp made no difference.

R

[Paul_Sengupta]

Regarding power/UPS hat, I have one of these on order but it hasn't arrived yet.

https://www.ebay.co.uk/itm/UPS-HAT-Board-Module-Lithium-Battery-2500mAh-For-Raspberry-Pi-3-Model-B-Pi-Hot/272884401173

[Seanhump]

Be interesting to see how you get on with it ...