TheBackShed.com

Forum Index : Microcontroller and PC projects : I2C2

Author

Message

georgestheking
Newbie

Joined: 21/12/2021
Location: Belgium
Posts: 32

Posted: 08:51pm 23 Jan 2025

Copy link to clipboard

Print this post

Hi,

I use an RP2040 in standard mode ( no USB / no VGA )
Version 6.01

When I try to configure the I2C2 I get an error

SETPIN GP26,GP27,I2C2

[151] SetPin GP26,GP27,I2C2
Error : Pin 31/GP26 is reserved on startup

Best regards

Georges

phil99

Guru

Joined: 11/02/2018
Location: Australia
Posts: 2605

Posted: 09:42pm 23 Jan 2025

Copy link to clipboard

Print this post

Start with Option List to see most of the used pins.
If that doesn't show what is using GP26 add this Sub to your program or the library.

Sub FreePins
local n%, p%, gp$
For n%=0 To 29
gp$ = "GP"+Str$(n%)
p% = MM.Info(pinno gp$)
Print gp$, p%, MM.Info$(pin p%)
Next
End Sub

Type FreePins to run it. It tests every pin.

Edit.
If the ADC OPEN command is in use GP26 will be locked to that as it is ADC0.
Edited 2025-01-24 09:28 by phil99

stanleyella

Guru

Joined: 25/06/2022
Location: United Kingdom
Posts: 2534

Posted: 04:05pm 24 Jan 2025

Copy link to clipboard

Print this post

There are two I2C channels. They can operate in master or slave mode.
I/O Pins
Before the I
2C interface can be used the I/O pins must be defined using the following command for the first
channel (referred as I2C):
SETPIN sda, scl, I2C
Valid pins are SDA: GP0, GP4, GP8, GP12, GP16, GP20 or GP28
SCL: GP1, GP5, GP9, GP13, GP17 or GP21

gp26,gp27 are keyboard maybe
Edited 2025-01-25 02:10 by stanleyella

Mixtel90

Guru

Joined: 05/10/2019
Location: United Kingdom
Posts: 7856

Posted: 04:44pm 24 Jan 2025

Copy link to clipboard

Print this post

They shouldn't be, Stan. Default keyboards are not I2C.

Phil is right. OPTION LIST for a start, and see if GP26 is already allocated to something.

Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs

stanleyella

Guru

Joined: 25/06/2022
Location: United Kingdom
Posts: 2534

Posted: 06:32pm 24 Jan 2025

Copy link to clipboard

Print this post

always followed the manual and examples. dunno why gp26,27 reserved. what for?

JohnS
Guru

Joined: 18/11/2011
Location: United Kingdom
Posts: 4037

Posted: 08:25pm 24 Jan 2025

Copy link to clipboard

Print this post

OPTION LIST - shows what?

John

stanleyella

Guru

Joined: 25/06/2022
Location: United Kingdom
Posts: 2534

Posted: 09:14pm 24 Jan 2025

Copy link to clipboard

Print this post

cool
autosav

Upload completed 1

Saved 165 bytes
>
Time taken: 714mS
RUN
GP0 1 Boot Reserved : AUDIO L
GP1 2 Boot Reserved : AUDIO R
GP2 4 OFF
GP3 5 OFF
GP4 6 Boot Reserved : SPI SYSTEM MISO
GP5 7 OFF
GP6 9 Boot Reserved : SPI SYSTEM CLK
GP7 10 Boot Reserved : SPI SYSTEM MOSI
GP8 11 Boot Reserved : CONSOLE TX
GP9 12 Boot Reserved : CONSOLE RX
GP10 14 OFF
GP11 15 OFF
GP12 16 Boot Reserved : HDMI
GP13 17 Boot Reserved : HDMI
GP14 19 Boot Reserved : HDMI
GP15 20 Boot Reserved : HDMI
GP16 21 Boot Reserved : HDMI
GP17 22 Boot Reserved : HDMI
GP18 24 Boot Reserved : HDMI
GP19 25 Boot Reserved : HDMI
GP20 26 OFF
GP21 27 OFF
GP22 29 Boot Reserved : SD CS
GP23 41 DOUT
GP24 42 DIN
GP25 43 HEARTBEAT
GP26 31 OFF
GP27 32 OFF
GP28 34 OFF
GP29 44 AIN
>

JohnS
Guru

Joined: 18/11/2011
Location: United Kingdom
Posts: 4037

Posted: 09:52pm 24 Jan 2025

Copy link to clipboard

Print this post

So they're OFF, I don't understand what the problem is.

John

Mixtel90

Guru

Joined: 05/10/2019
Location: United Kingdom
Posts: 7856

Posted: 10:52pm 24 Jan 2025

Copy link to clipboard

Print this post

Erm... it wasn't Stan that asked...

Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs

JohnS
Guru

Joined: 18/11/2011
Location: United Kingdom
Posts: 4037

Posted: 11:10pm 24 Jan 2025

Copy link to clipboard

Print this post

I don't mind who posts an explanation, the OP preferably but hey anyone...

John

Print this page

To reply to this topic, you need to log in.