[0:02] In the previous video, we prototyped our LED driving circuit.
[0:07] In this video we will build out the complete schematic for our Moon Lamp.
[0:13] And in the followup video, we’ll layout our PCB and send it off for manufacture with JLPCB.
[0:20] I’ve started a new project in EasyEDA and we’ll start to build our schematic.
[0:28] I’ve already looked up the parts that I want to use, so let’s get started!
[0:35] I’m going to power the moon lamp from a 5v USB power supply so the first thing we
[0:45] will need is a 3.3v regulator.
[0:48] We’ll use the AMS1117-3.3 which is a basic part on JLPCB.
[0:57] We’ll also need to add some capacitors to the input and the output of the regulator.
[1:06] So let’s add those components and wire them up.
[1:30] We’ll also need a way to get power onto the board so we’ll add a screw terminal.
[1:44] So that’s our power regulator finished.
[1:48] Let’s move onto our ESP32 Wroom module.
[1:55] It’s recommended to add a decoupling capacitor close to the power input to this module so
[2:02] we’ll add a 10uF capacitor.
[2:05] It’s also recommended to add an RC circuit to the enable pin so that the module is disabled
[2:15] while the power supply stabilized.
[2:18] We’ll add a 12Kohm and 100nF capacitor.
[3:16] That’s our ESP32 module all wired up.
[3:23] For the output drivers, we are going to need a MOSFET.
[3:29] JLPCB has a basic part that will serve our needs so we’ll use this.
[3:35] We also need a gate resistor, a pull-up resistor and the LED resistor.
[3:42] We’ll have a 470 ohm gate resistor and a 470 ohm pull up resistor.
[3:50] And for the LED resistor we’ll use a 1 Watt 5.1 ohm resistors.
[3:57] So we’ll wire this up now.
[4:25] Let’s also wire up GPI02 to an LED so that we can do a simple blink sketch to test our
[4:36] PCB when it arrives.
[4:39] We’ll put in an LED and a resistor and connect that to GPIO2.
[4:53] It’s probably also handy to have some indicators that that we have power coming into the board
[5:00] so we’ll add a connection to the 5v the 3.3v regulator so we can see it is working properly.
[5:13] I’m not including a USB to serial chip, we’ll use an external USB to serial chip.
[5:23] TX and RX are both active low and it’s handy to see if they are doing anything.
[5:33] So we’ll wire up TX and RX to an LED as well.
[5:48] Let’s also expose out all the GPIOs so we can expand our board if we need to.
[6:00] So let’s put in some headers.
[6:31] That’s our schematic all done.
[6:34] In the next video, we’ll lay out the PCB and send it off for manufacture with JLPCB.
[6:42] We’ll probably change the ordering of these pins and these pins to make it easier to lay
[6:50] the board out.
[6:52] But it should be a fairly straightforward board.
[6:55] If you like the content please hit subscribe and like.
[7:00] And I’ll see you in the next video.