Electronics Production

This week, we will practice the PCB production process, manufacture and test microcontrollers, which also involves soldering. It's going to be a fun week!

1.1 Assignments of the Week

Group assignment:

• Characterize the design rules for your in-house PCB production process: document feeds, speeds, plunge rate, depth of cut (traces and outline) and tooling.

• Document the workflow for sending a PCB to a board house

• Document your work to the group work page and reflect on your individual page what you learned

Individual Assignment:

• Make and test a microcontroller development board

1.2 Group Assignment

Here is our grorup assignment of this week.

1.2 Individual Assignment

I started with Adrián Torres's example but added two rows of Xiao's connectors using Photoshop.

1.2.1 Source file

Photoshop modification

1.2.2 modsproject

Open mods CE

programs-open program-Roland-MDX mill-PCB

select png file-dpi:1000-set PCB defaults

While cutting the holes, I forgot to modify the DPI, causing the machine to malfunction. Later, I changed the parameters and re-uploaded the file, and it succeeded.

mill raster 2D

Modify based on the data of the group assignment.

model:MDX40-origin-save

Be sure to change the starting point; otherwise, it will be very severe.

calculate-view

1.2.3 Milling

I used a 0.4mm endmill for cutting the circuit, and a 0.8mm endmill for cutting the outline and holes.

Modify the x, y, z axes-output the file

The first milling

This process was repeated three times.

The first attempt failed due to foreign objects at the bottom, and the Z-axis was elevated by 0.2mm. The solution was to recalibrate the Z-axis.

On the basis of the first milling, we did not change the starting point and milled again. The tool broke midway.

The third time, I checked the tool and found that it had not broken completely. So, I adjusted the z-axis and milled it again. However, it was still too rough, and the fine circuits in the middle had already been milled off.

The second milling

Replaced the milling bit and it worked perfectly.

1.2.4 Solder

Following the circuit diagram provided by MIT, I embarked on the thrilling journey of soldering.

Find the components.

Set the soldering iron temperature to 350, and start my first complete soldering.

1.2.5 Test

I will perform two blink tests using the Seeed Xiao RP2040 development board in the Arduino IDE. I followed the official tutorial

seeed xiao-RP2040

A blink:

int LED_BUILTIN=1; void setup() { // initialize digital pin LED_BUILTIN as an output. pinMode(LED_BUILTIN, OUTPUT); } // the loop function runs over and over again forever void loop() { digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(1000); // wait for a second digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW delay(1000); // wait for a second }

Two blink:

int LED_BUILTIN1=1; int LED_BUILTIN2=26; void setup() { pinMode(LED_BUILTIN1, OUTPUT); pinMode(LED_BUILTIN2, OUTPUT); } void loop() { digitalWrite(LED_BUILTIN1, HIGH); delay(1000); digitalWrite(LED_BUILTIN1, LOW); delay(1000); digitalWrite(LED_BUILTIN2, HIGH); delay(1000); digitalWrite(LED_BUILTIN2, LOW); delay(1000); }