8. Electronics Design¶
Introduction to Electronics Design Week¶
Welcome to Week 8: Electronics Design! This week, we immerse ourselves in the world of electronics design with a special project focus on creating a development board for the Seed Xiao RP2040 microcontroller. As we delve into the intricacies of electronic circuitry, our primary goal is to conceptualize, design, and fabricate a versatile development platform tailored specifically for the Xiao RP2040. Throughout this journey, we will explore fundamental principles of electronics, experiment with circuit design techniques, and leverage our creativity to craft a robust and functional board that unlocks the full potential of the RP2040 microcontroller. Join us as we embark on this hands-on endeavor, poised to innovate and redefine possibilities in electronics design.
Software’s Tried¶
- EasyEDA
Assignment¶
Make and test a microcontroller development board. We had to make a devlopment board. Instead of that I actually made a board that connects the 4 digit 7 segment display to the rp2040. Then I realised that we had to make a devlopment board.
Designing the PCB¶
I started making my own very first PCB for this week. I have made a breakout borad for this week which I designed and produced on my own. For this I first had to explore the software of easyEDA because it was all new to me.
So there are 3 major steps that I have figured in order to Design and produce a PCB
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Create a Schematic diagram of your PCB
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Create the gerber file of your PCB
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Mill and solder your PCB
Lets go step by step I explored the software by designing a random PCB just so that I get used to the software.
Schematic Diagram¶
This is the Interface of the EasyEDA software where we first build the schematic diagram of your PCB that you are making.
This is the component Library in the EasyEDA software, where you can search for the any component that you want in your PCB. The library also has User contributed column where there are custom components as well that have been added by many people. In the library you get all the footprints and symbols for your PCB.
These are the wiring tools which help you to connect all the components that you select from the library.
Now here after connect all the components with the wiring tools you the click on the convert to PCB option under the Design option on the top panel.
Before you click the covert to PCB option the software itself will tell you to check if all the nets are closed. As you can see one of the nets in my schematic is not closed if you click on the net that is not closed it will locate you to the net that is not closed.
This the net that is not closed so here I just, use the wiring tool and close the net. Now all the nets are checked and closed now we can go ahead with converting it to the PCB.
PCB Design¶
After you click the convert to PCB it first tells you to make the rectangle of the size you want for your PCB it automatically suggests you the rectangle dimensions according to the components in your PCB.
Now you arrange your components in the in the rectangle that you have created for your PCB. Place the components where you need.
After you have placed all the components inside of the rectangle we need to make a route for all the connections we can either manually do the routing or we can just auto route which is much much easier. Just go on to the route column on the top panel and click autoroute.
After clicking on to the autoroute we need to check the design rules for the autoroute, the design rules are for the dimensions of the track width and also for the through holes in your PCB.
after you check the design rules just start the routing in your PCB. after the routing is done it gives you if any routeing is failed or how many routing are there.
After you are done with your routing and you are satisfied with now you need to download the gerber file for the same. To download the gerber file you just need to go to the top panel and in the fabrication column there is an option for genrating gerber file as shown below.
Click on the PCB fabrication gerber it tells you to do a DRC check before you fabricate it. Do the DRC check see if there is a problem in it, if there is a problem in the routing it will tell you about it.
After doing the DRC check you are ready with your PCB design! just download the gerber file.
click on generate gerber and you are good to go!!
Designing Breakout board for seed xiao RP2040¶
Schematic diagram¶
This is the schematic file that I have made for this week, It is essentially a breakout board for my microcontroller seed xiao RP2040. I have also added a test button and a test led attached to it so that we can test the PCB if its working or not without attaching any other input or output device. All the footprints of the components are taken from thr library in the easyEDA itself.
PCB Design¶
After getting the jist of the layout of the components from the schematic design, I made the layout in the rectangle of my PCB. After the components were all alinged together I did the routing, I tried to do the auto routing but the auto routing failed. I had to do all the routing manually according to layout and here it is. It actually came out well.
PCB Milling!¶
The machine we use for PCB milling is SRM 20
This the machine we had also used for our Electronic Production week. Lets get onto the process
Process
First you select the top layer file from your gerber file. go to open < New circuit.
select the top layer file.
This is what it looks like in copper CAM when you open the top layer is oppened.
After this we need to add the drill layer, same step go to file > drills
The drill holes come on top of the the layer that is already there but now the problem over here is that the holes are not alligned properly to the place it should be.
No worries! for this select the top layer and right click to any pad where the drill hole is going to be and set it as a reference pad.
Then select the drill file again and the hole on the pad that you have made your referencr pad slect that hole and right click < Adjust to reference pad 1.
And done the holes are now aligned.
Once the holes are now aligned we add the outer layer for cutting from the same method file < Drills
Once the file comes on the copper cam we need to allign it ro the origin of the file. right click the outer boundary and click centre horizontally and vertically. (Note: this will also depend on the origin point you have set in your copper CAM.)
Now the outer box is also alligned.
After all the layers are now set we set the track width that we want for our file. (normally I prefer 0.7)
After setting the track width we set the pad width I keep it in the range of 0.7- 2.2 this makes the soldering much easier.
Once the track and pad widths are set we define the number of contours we want. I set from 7-9 so that there is no shot in the circuit.
Finally the file is ready for milling and we are done!
Final Milled and soldered PCB¶
PCB Working¶
I had attached a Led to my board that I had designed this week and now was the time to check if the board works! I had put a simple blink code to the led which I had installed on my board and guess what yess its working!!!
Code for Blink¶
// Define the pin for the LED
const int ledPin = 7;
void setup() {
// Initialize the digital pin as an output.
pinMode(ledPin, OUTPUT);
}
void loop() {
// Turn the LED on (HIGH is the voltage level)
digitalWrite(ledPin, HIGH);
// Wait for a second
delay(1000);
// Turn the LED off by making the voltage LOW
digitalWrite(ledPin, LOW);
// Wait for a second
delay(1000);
}
Group Assignment¶
The Group assignment for this week has been put up on Himanshi Jain’s Website Himanshi Jain’s Webpage
My reflection
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In this weeks grp assignment we learnt how to use the ossciloscope for the first time.
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learnt how to see the waveforms of the led.