Using EasyEDA to develop a PCB

Making a Printed Circuit Board using EasyEDA and JLCPCB

This page will highlight my problems what I would do different next time.

There are a number of Web Videos on developing a PCB and having it manufactured by JLCPCB.

It is suggested that interested parties view some of these videos. This page will list some of my mistakes and recommendations after developing my first board using EasyEDA. Remember nothing in life is easy the first time you do it so developing a product will not be as straightforward as some of these web videos will have you believe.

General Comments

1. My first project was way too big and complicated for a first project and led to mistakes. ** See Appendix

2. I was doing too many things in parallel. Try and concentrate on one project and one aspect of that project.

3. I was never really comfortable with the operation of the left and right click, the up-down and left-right arrows and the scroll command. This meant I was not always in the mode I thought I was in with the result I was moving tracks or chips when I thought I was doing something else. Especially when laying out the PCB tracks I would recomend doing a save after each new track is laid.

4. Some of my tracks were pretty crummy. Part of this was due to my mouse having to compete for desk space. Make sure there is plenty of space to move your mouse. Along with issue 3 this problem was compounded in my project with trying place a track between two pins and then take it to the other side of the board.

Before attempting the schematic

5. I tended to do some the design at the same time. While I had made a working breadboard I really had not documented my design. Draw up the final design prior to opening EasyEDA. Make copies and notate on one as each component is added to EasyEDA. You will need to note the labels assigned by EasyEDA. Double check pin numbering especially for connectors and top/bottom views.

6. I flirted between doing the schematic capture and finding the next component in the EasyEDA library. Better to first make a list all the components you will need and then go to the EasyEDA and find the component that meets your needs. For most components there are several options. For example, surface mount or pinhole - different types of packages. In my design I selected (accidently) one voltage regulator that used the PCB as a heat sink and the other was free standing. Its is better to decide on your options before starting on schematic capture.

The schematic

7. Once you have a circuit diagram and a BOM (Bill of materials - or list of components) the schematic may be attempted. Left click to place component and right click to get out of place mode. Rotate and move components as required.

8. Select wiring tool and start to draw wires. Make sure go to wires or past component. DB9 sockets in circuit below. There should be RED dots at connection..

9. I found that the red dots were not always present. By doing a Design Rules Check it is possible to see the net list - Design --> Convert to PCB --> Do rules check. This will give a list of all pins with unused pins.

Component C1 should only have 2,3 & 4 connected at this stage. As shown pins 1, 5, 6, 7, 8 and 9 there are missing connections (!). Scrolling down the list it will be seen that U1_16 is valid and clicking on U1_16 for example will highlight the connection to C1_2.

10. As more components are added it becomes more difficult to neatly complete the wiring. I should have been prepared to experiment with the Net Port operation. (The pentagon symbol) Also a Ground/Earth should have been added. EasyEDA doesn't know U1_29 is ground. Note there are not red dots on all connections but performing a DRC (Design Rules Check) verifies the connections are made.

The PCB Layout

11. Converting the schematic to a PCB (Design --> Convert to PCB --> No rules check.) will give a possible PCB. Use suggested board dimensions and modify as required later. (When board is "complete" delete board outline, use Fabrication --> PCB -->Get Dimensions then in Tools-->Set Board Outline and use dimensions found)

12. Move "critical" components close to desired positions. I needed DB9 (RS232) connectors along one edge of the board. The USB socket on the Arduino NANO needed to be at a clear location for a cable to a PC. The 4 servo connectors P4-P6 need to be moved to edge of board.

13. The initial PCB highlighted some mistakes. Resistors and Capacitors were surface mount and the 10ufd capacitor filter on the power supply was physically the wrong size. The lesson was to list the BOM with the correct components before the schematic was started. Note making changes to the schematic takes you back to square one in developing the PCB. Make sure the schematic is correct before moving to the PCB. Cross check all the wiring with the circuit. See step 5.

14. Duplicating all the paths of the rats nest is a time consuming task. Devices will need to be moved as one tries to place the PCB tracks. It will be necessary to zoom-in to place a PCB track between pins of a component, then zoom out to take the track to its other connection. The left-right, up-down keys will need to be used to centre the PCB about the point of interest. I found I was making many mistakes so would recommend after each track is added save your work. See items 3 and 4.

15. My recommended sequence is (i) if possible position the layout so the end points of the track are both on screen. (ii) select wiring tool (iii) left click on starting point (iv) move/juggle the cursor to get the track going where you want to an intermediate point (v) left click to fix position (vi) repeat step iv until you reach the end point (vii) right click to finish track (viii) right click again to get out of track laying mode and (ix) if satisfied save the layout.

16. Before doing my next board I would try and understand the hot keys for adding via's and removing right angle bends.

17. Perform a solder fill top and bottom. Since I had not included a ground in my design I needed to specify pin U1_29 as the reference. I did not do a good job of the solder fill outline and was unable to delete and start the fill again - try and get it correct the first time!

The Gerber File and Ordering the PCB

18. Use Fabrication -->PCB Fabrication File (Gerber). This is a two step process - at the bottom of the next screen select Generate Gerber

19. Order at JLCPCB -(Fabrication -->PCB Order) JLCPCB will require you to upload the Gerber file in ZIP format.

20. I accepted all the details and moved to order quantity and shipping. JLCPCB advise that a Gerber Check should be performed but I didn't know what I was looking for so ignored it (Examples on www seem to bypass any checking also).

21. If the design fails JLCPCB will send an email advising of the problem. Correct the issue and move to JLCPCB Order History --> Replace File. The last thing you should do is try and start again. (You will drive JLCPCB and yourself into knots). You need to build on an existing order. Once correct JLCPCB will advise you that payment is now required.

Follow up and more lessons

See board 2 - board 3

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Appendix: The target projects.

(Just for interest) the target projects were:

Model train dual single track controller. Detectors at both ends of a single track detected a train and set the track signals to red until the train had passed. The basic components are shown below are the voltage supply that uses the track voltages, the NANO micro controller and 4 DB9 connectors for wiring to sensors and signals at both ends of the track. Laying out the tracks for the DB9s was the most challenging part of the project.

Model train scissor Cross Over Servo Controller. This circuit detects the command (straight or turn) from the track and operates the servos to move the points. Since not all pins were required these can be used for other applications. For example signals at the cross over.

In combining the two functions there was only one conflict. The 4 signals use all of pins D2 through D13. The 4 servos use D3 through D6. Since D3-D6 are outputs in both designs they are wired in parallel - the completed board would only connect the appropriate components. However for the point controller D2 is an input so the PCB includes a jumper to select the D2 wiring. Either from the track or to one of the signals.

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