WEBVTT 00:00.110 --> 00:05.360 Here is the complete pinout for the Raspberry Pi five, but it's also the same as for the Raspberry 00:05.360 --> 00:07.130 Pi four, three and two. 00:07.160 --> 00:13.370 The Gpios haven't changed with the latest evolution of the board, so as you can see we have some pins 00:13.370 --> 00:16.070 in black which represent the ground. 00:16.250 --> 00:17.660 We've already used one. 00:17.690 --> 00:20.060 All those pins are connected together. 00:20.060 --> 00:22.190 Then we have what we call power pins. 00:22.190 --> 00:28.430 So we have two pins for 3.3V in yellow and two pins for five volts in red. 00:28.430 --> 00:30.860 Then we have the Gpio in orange. 00:30.860 --> 00:34.940 So again Gpio means general purpose input output. 00:34.940 --> 00:37.760 And each Gpio has a number. 00:37.760 --> 00:43.160 That's the number you will use in your Python code to interact with that Gpio. 00:43.160 --> 00:49.040 And a quick reminder here is that Gpio supports 3.3V, not five volt. 00:49.070 --> 00:51.770 We only have two pins here that support five volt. 00:51.770 --> 00:55.130 So now how are Gpios controlled? 00:55.130 --> 00:57.200 Well, it's pretty simple. 00:57.230 --> 01:02.840 A Gpio will be set as either an input pin or an output pin. 01:02.840 --> 01:06.140 Input will be used when you want to read some data. 01:06.140 --> 01:11.870 For example, with a push button you want to read, the state of the button and output will be used 01:11.910 --> 01:13.950 when you want to write some data. 01:13.980 --> 01:18.990 For example, you want to set an LED, so you want to turn on or off an LED. 01:18.990 --> 01:23.730 So once the mode for the Gpio is set, you can use it. 01:24.120 --> 01:27.390 If it is set as an input, you can read a value. 01:27.420 --> 01:30.810 The value has only two states high and low. 01:30.810 --> 01:32.460 So this is a binary state. 01:32.460 --> 01:37.290 And high and low here correspond to the voltage which was read from the pin. 01:37.290 --> 01:44.310 If the voltage is high enough and close to 3.3V, then the value will be high, otherwise it will be 01:44.310 --> 01:44.670 low. 01:44.670 --> 01:49.650 And if you have set the Gpio as output, you can then write a value to it. 01:49.650 --> 01:52.920 And it's also going to be high or low for an LED. 01:52.920 --> 01:58.920 If you want to turn on the LED, the Gpio state will be high, so close to 3.3V. 01:58.920 --> 02:05.790 And if you want to turn off the LED, the Gpio state will be set as low so close to zero volts. 02:05.790 --> 02:08.730 And that's basically how a Gpio works. 02:08.760 --> 02:08.910 Okay. 02:08.940 --> 02:10.140 It's not that complicated. 02:10.140 --> 02:14.520 And in the code we will use a Python library that takes care of all that for you. 02:14.520 --> 02:17.550 So basically we won't have to deal directly with this. 02:17.550 --> 02:20.820 And you can just then focus on your application. 02:20.820 --> 02:27.730 But with what you've seen here in those few minutes, at least you understand the basics of how it works 02:27.730 --> 02:28.570 under the hood. 02:28.600 --> 02:34.630 Now, if we come back to the Raspberry Pi pinout image, you can see that the Gpios are not set in any 02:34.630 --> 02:37.810 specific order and some numbers are missing. 02:37.840 --> 02:39.280 And that's totally okay. 02:39.310 --> 02:40.810 And it's nothing to worry about. 02:40.810 --> 02:46.390 You just have to be extra careful when finding the Gpio number corresponding to the Pin number. 02:46.420 --> 02:47.830 Okay, so you can see the pin number. 02:47.830 --> 02:50.380 We have numbers from one until 40. 02:50.380 --> 02:52.990 So those are the gray pins and they are ordered. 02:52.990 --> 02:55.570 But we are not going to use those numbers. 02:55.570 --> 02:59.050 We are going to use the Gpio numbers directly. 02:59.050 --> 03:00.790 And then what else do we have. 03:00.790 --> 03:05.110 You can see that we also have two reserved pins in gray. 03:05.110 --> 03:06.940 So you should not use those. 03:06.940 --> 03:11.380 Then we have two pins in green that are used for Uart communication. 03:11.380 --> 03:16.060 You also have alternate functions with I to C and SPI communications. 03:16.060 --> 03:18.970 So all those are more advanced communications. 03:18.970 --> 03:22.030 And in this course we are just going to focus on the Gpio. 03:22.030 --> 03:26.620 But if you want to learn more about those communications that can be a nice thing to research after 03:26.620 --> 03:27.220 this course. 03:27.250 --> 03:27.670 All right. 03:27.700 --> 03:34.690 And now that you have an overview of how Gpio work, let's actually use one to power on our first LED.