deepakdeshp
Posts: 103
Joined: Thu Oct 26, 2017 7:23 pm

Raspberry pi 1 26 pins and corresponding pins in Pi 3B

Wed Aug 28, 2019 2:01 pm

Hello,
Pi 1 model has 26 pins while Pi 3b has 40. So is it that the first 26 pins of Pi 3B correspond to the 26 pins of Pi 1?

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scruss
Posts: 2418
Joined: Sat Jun 09, 2012 12:25 pm
Location: Toronto, ON
Contact: Website

Re: Raspberry pi 1 26 pins and corresponding pins in Pi 3B

Wed Aug 28, 2019 2:11 pm

Almost. Issuing pinout shows the differences, here place side by side using the paste command:

Code: Select all

         40 pin                          26 pin
=======================          ======================
   3V3  (1) (2)  5V                3V3  (1) (2)  5V    
 GPIO2  (3) (4)  5V              GPIO0  (3) (4)  5V    
 GPIO3  (5) (6)  GND             GPIO1  (5) (6)  GND   
 GPIO4  (7) (8)  GPIO14          GPIO4  (7) (8)  GPIO14
   GND  (9) (10) GPIO15            GND  (9) (10) GPIO15
GPIO17 (11) (12) GPIO18         GPIO17 (11) (12) GPIO18
GPIO27 (13) (14) GND            GPIO21 (13) (14) GND   
GPIO22 (15) (16) GPIO23         GPIO22 (15) (16) GPIO23
   3V3 (17) (18) GPIO24            3V3 (17) (18) GPIO24
GPIO10 (19) (20) GND            GPIO10 (19) (20) GND   
 GPIO9 (21) (22) GPIO25          GPIO9 (21) (22) GPIO25
GPIO11 (23) (24) GPIO8          GPIO11 (23) (24) GPIO8 
   GND (25) (26) GPIO7             GND (25) (26) GPIO7 
 GPIO0 (27) (28) GPIO1          
 GPIO5 (29) (30) GND            
 GPIO6 (31) (32) GPIO12         
GPIO13 (33) (34) GND            
GPIO19 (35) (36) GPIO16         
GPIO26 (37) (38) GPIO20         
   GND (39) (40) GPIO21   
Physical pins 3 & 5 have different functions now.
‘Remember the Golden Rule of Selling: “Do not resort to violence.”’ — McGlashan.

pcmanbob
Posts: 6619
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Raspberry pi 1 26 pins and corresponding pins in Pi 3B

Wed Aug 28, 2019 2:24 pm

It depends if you pi 1B is a revision 1 or a revision 2 as several pins changed between them,

the revision 2 has the same first 26 gpio pins as the pi1B, 2B, 3B & 3B+

Image

To figure out which you have run

Code: Select all

 cat /proc/cpuinfo
 
which will give the following results

Code: Select all

[email protected]:~ $  cat /proc/cpuinfo
processor       : 0
model name      : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS        : 697.95
Features        : half thumb fastmult vfp edsp java tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xb76
CPU revision    : 7

Hardware        : BCM2835
Revision        : 0002
Serial          : 000000003d0740f5
now if you look at the revision number which in this case is 0002 you can use this chart to figure out which revision you have

Image

in this example I ran the command on my early pi 1B revision 1 with 256MB of ram.

if you are running raspbian jessie , stretch or buster you can also get the revision by running

Code: Select all

cat /proc/device-tree/model
which when run on the same pi 1 B as used for the above gives this result

Code: Select all

Raspberry Pi Model B Rev 1

old but useful https://www.raspberrypi-spy.co.uk/2012/ ... d-version/
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

deepakdeshp
Posts: 103
Joined: Thu Oct 26, 2017 7:23 pm

Re: Raspberry pi 1 26 pins and corresponding pins in Pi 3B

Thu Sep 12, 2019 2:48 pm

pcmanbob wrote:
Wed Aug 28, 2019 2:24 pm
It depends if you pi 1B is a revision 1 or a revision 2 as several pins changed between them,

the revision 2 has the same first 26 gpio pins as the pi1B, 2B, 3B & 3B+

Image

To figure out which you have run

Code: Select all

 cat /proc/cpuinfo
 
which will give the following results

Code: Select all

[email protected]:~ $  cat /proc/cpuinfo
processor       : 0
model name      : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS        : 697.95
Features        : half thumb fastmult vfp edsp java tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xb76
CPU revision    : 7

Hardware        : BCM2835
Revision        : 0002
Serial          : 000000003d0740f5
now if you look at the revision number which in this case is 0002 you can use this chart to figure out which revision you have

Image

in this example I ran the command on my early pi 1B revision 1 with 256MB of ram.

if you are running raspbian jessie , stretch or buster you can also get the revision by running

Code: Select all

cat /proc/device-tree/model
which when run on the same pi 1 B as used for the above gives this result

Code: Select all

Raspberry Pi Model B Rev 1

old but useful https://www.raspberrypi-spy.co.uk/2012/ ... d-version/
Thanks for the update.

deepakdeshp
Posts: 103
Joined: Thu Oct 26, 2017 7:23 pm

Re: Raspberry pi 1 26 pins and corresponding pins in Pi 3B

Thu Sep 12, 2019 2:48 pm

scruss wrote:
Wed Aug 28, 2019 2:11 pm
Almost. Issuing pinout shows the differences, here place side by side using the paste command:

Code: Select all

         40 pin                          26 pin
=======================          ======================
   3V3  (1) (2)  5V                3V3  (1) (2)  5V    
 GPIO2  (3) (4)  5V              GPIO0  (3) (4)  5V    
 GPIO3  (5) (6)  GND             GPIO1  (5) (6)  GND   
 GPIO4  (7) (8)  GPIO14          GPIO4  (7) (8)  GPIO14
   GND  (9) (10) GPIO15            GND  (9) (10) GPIO15
GPIO17 (11) (12) GPIO18         GPIO17 (11) (12) GPIO18
GPIO27 (13) (14) GND            GPIO21 (13) (14) GND   
GPIO22 (15) (16) GPIO23         GPIO22 (15) (16) GPIO23
   3V3 (17) (18) GPIO24            3V3 (17) (18) GPIO24
GPIO10 (19) (20) GND            GPIO10 (19) (20) GND   
 GPIO9 (21) (22) GPIO25          GPIO9 (21) (22) GPIO25
GPIO11 (23) (24) GPIO8          GPIO11 (23) (24) GPIO8 
   GND (25) (26) GPIO7             GND (25) (26) GPIO7 
 GPIO0 (27) (28) GPIO1          
 GPIO5 (29) (30) GND            
 GPIO6 (31) (32) GPIO12         
GPIO13 (33) (34) GND            
GPIO19 (35) (36) GPIO16         
GPIO26 (37) (38) GPIO20         
   GND (39) (40) GPIO21   
Physical pins 3 & 5 have different functions now.
Thank you.

deepakdeshp
Posts: 103
Joined: Thu Oct 26, 2017 7:23 pm

Re: Raspberry pi 1 26 pins and corresponding pins in Pi 3B

Sat Sep 14, 2019 2:07 am

My model is

Code: Select all

cat /proc/device-tree/model
Raspberry Pi Model B Rev 1

pcmanbob
Posts: 6619
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Raspberry pi 1 26 pins and corresponding pins in Pi 3B

Sat Sep 14, 2019 9:47 am

deepakdeshp wrote:
Sat Sep 14, 2019 2:07 am
My model is

Code: Select all

cat /proc/device-tree/model
Raspberry Pi Model B Rev 1
In that case there are some differences between your gpio and that of the first 26 pins of the 40 pin gpio.

you need to use this pin layout for your pi.

Image

As pins 3,5 & 13 are different gpio numbers.
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

fruitoftheloom
Posts: 20431
Joined: Tue Mar 25, 2014 12:40 pm
Location: Delightful Dorset

Re: Raspberry pi 1 26 pins and corresponding pins in Pi 3B

Sat Sep 14, 2019 9:53 am

adieu

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