GPIO Pin mapping

Question

Hi, I'm switching from Linux to Win IOT to give it a try. And I have a huge surprise on pin numbering and availability. I did try to open each PIN to ensure my mapping was correct... gpioResult contains the test result which I convert then to array for more readability.

            string gpioTest = "";
            for(int i = 0; i < 55; i++)
            {
                try
                {
                    pin = gpio.OpenPin(i);
                    pin.Write(GpioPinValue.High);
                    pin.SetDriveMode(GpioPinDriveMode.Output);
                    gpioTest += "Ok with pin " + i + "@";

                }catch(Exception ex)
                {
                    gpioTest += "Failed with " + i + " " + ex.Message + "@";
                }
            }

The result doesn't map any GPIO picture I found on Raspberry pi 2 or wiring PI :

0	Failed
1	Failed
2	Failed
3	Failed
4	Ok
5	Ok
6	Ok
7	Failed
8	Failed
9	Failed
10	Failed
11	Failed
12	Ok
13	Ok
14	Failed
15	Failed
16	Ok
17	Failed
18	Ok
19	Failed
20	Failed
21	Failed
22	Ok
23	Ok
24	Ok
25	Ok
26	Ok
27	Ok
28	Failed
29	Failed
30	Failed
31	Failed
32	Failed
33	Failed
34	Failed
35	Ok
36	Failed
37	Failed
38	Failed
39	Failed
40	Failed
41	Failed
42	Failed
43	Failed
44	Failed
45	Failed
46	Failed
47	Ok
48	Failed
49	Failed
50	Failed
51	Failed
52	Failed
53	Failed
54	Failed

Any idea ? My RPI was working fine on Linux one week ago (I've to recognize I didn't test all GPIO before to switch, but the result can't come from a bug, I'm missing something)

Answer 1

From the FAQ at https://www.raspberrypi.org/forums/viewtopic.php?f=105&t=123945

42. Which GPIO pins can I use

Running a slightly modified version of

https://github.com/ms-iot/samples/tree/master/GpioTestTool to output to a file

On Insider Preview 10556 it reports

The default GPIO controller has 54 pins:
Pin 4 is available
Pin 5 is available
Pin 6 is available
Pin 12 is available
Pin 13 is available
Pin 16 is available
Pin 17 is available
Pin 18 is available
Pin 19 is available
Pin 20 is available
Pin 21 is available
Pin 22 is available
Pin 23 is available
Pin 24 is available
Pin 25 is available
Pin 26 is available
Pin 27 is available
Pin 35 is available
Pin 47 is available

which appears to support your conclusions. But what other pins would you want. All of the pins on the header are now in use, only the HAT pins reserved (from 10556 Serial Rx/Tx are supported as well)..

6. Find out which pins on the header are available for use and for what purposes

https://ms-iot.github.io/content/en-US/win10/samples/PinMappingsRPi2.htm

---

riclh

Answer 2

Hi, thanks for your answer and for the link, seems ideas wasn't that clear for me yesterday night. I spent time testing before to post, but I better should have sleep first ;). The 'pin' word makes me take a wrong way.

Answer 3

Oops, maybe I've gone too fast.

How do you play with GPIO 17 on pin 11 ?

pin = gpio.OpenPin(11); // Exception
pin = gpio.OpenPin(17); // Exception

Both are failure (shown in red in my first post array)

This GPIO works fine under Linux (used for watering)

Answer 4

I would suggest that you build and run the text example that I linked to above and see if it gets the same results. Also, check you are on 10556 as not all the pins are supported on OS before that.

https://ms-iot.github.io/content/en-US/Downloads.htm

---

riclh

Answer 5

Done, same result with C++ project (a lot faster to browse 54 pins).

Following couples (GPIO,pin) don't work under IOT :

(17, 11) ; (19,35) ; (20,38) ; (21,40)

My IOT / Raspberry pi version :

Device Name:	Raspberry1
Device Model:	Raspberry Pi 2 Model B
OS Version:	10.0.10240 (the latest version available to download)

Answer 6

The latest fully released version is 10240. That has a more limited set of pins available.

If you want all the pins then you will need to go to 10556 (i.e. the Insiders branch).

https://ms-iot.github.io/content/en-US/Downloads.htm

---

riclh

Answer 7

Thanks a lot ! All GPIO are active now as shown by Microsoft in its pictures.

The insider version (01/10/2015) was the key.

Time to play :)