Project Development

What tasks have been completed, and what tasks remain?

I start from my weakest part, electronics. In my original plan, I will finish the electronic production for my final project and testing before 28th, but due to MakerFiare Taipei was held last weekend and many Fab Lab friends from Asia visit Taipei, my progress was fall behind. I finalize the electronic part. Basically, it's two Arduino board with a LCD display scoring system, with two CNY70 optical reflective sensors, so when the pin ball fell to the bottom, it will calculate the score.

What questions need to be resolved?

I start from using one board at a time, because I want to use some kind of network structure for the electronic parts for my final project. But when sending data between boards, sometime the format cause problem. So I was struggling on how should I transfer my data, what type of data format I should use? and string or digit are more suitable in this case Here are some testing code that I've done regarding sending and receiving data


char str[6] = {0};

void setup() {
  str[0] = '0';
  str[1] = '0';
  str[2] = ':';
  str[3] = '0';
  str[4] = '0';

void loop() {
Because I want the score to be show as 00:00 format, so this is the solution that I came up with.


char str[6] = {0};

void setup() {

void loop() {

  if (Serial.available()) {
      Serial.readBytes(str, 5);

What tasks need to be completed?

My very original plan was to build an X shape pinball table that could be play by four people at the same time. Later on I found that this project is way much bigger than I thought. So I reduce the whole project into a two people’s battle game.
This is the first schematic diagram, At that time it still has four CNY70 sensor unit

What will happen when?

I need to make a counter mechanism that calculate the score as the sensor sense the ball drop to opponents hole. So the data maybe has to calculate on the first board (with censors) and the other board simply receive data and show in LCD screen.

What has worked? what hasn’t?

During the whole semester, I was always battling about the material issue, I kind of have to sourcing all the material by myself, but for shopping something I don’t even understand, it wasn’t that easy. Buying electronic part in Taiwan wasn’t too hard, but a common issue is: not easy to find the standardize fab inventory stuff. For instance: I can find 0805 or 0603 size of SMD resistor or capacitor easily here in Taipei, but for 1206, it is kind of difficult. Also its much easier to find dip pins than SMD components. So I end up with going back and forward to remake my circuit board many times. And welding 0805 and 0603 is crazy. Those things are just way too small. This is also an early version about my board design, to make holes for dip components, I went back to remodify some layout, also flip the board for welding from back side later.

I planned to put a resin casting CNC part in the middle of my pinball table. But it is raining season now in Taipei, we have huge rain almost every day. So the resin casting never completely dry. The CNC came out well, but the resin casting failed. Maybe part of the reason because I used chemical wood as a mild material, and that things might not be a good choice for making mold.

What have you learned?

I should manage my time better, Managing a fablab and taking Fab Academy at the same time is crazy, especially Fablab Taipei is opened almost 7 days a week, and I still have a lot of customer service things to do. In the middle of this semester, especially when the electronic parts begin, I was so regret that why I didn’t study somewhere else instead in my own Fab Lab, I do hope I can go through this process again if I can concentrate on my study. In Taipei, I just have very little time can focus on my study and project.

Spiral development

I tried to spiral develop this project, So I did CNC and 3D Printing at the same time, Something went wrong abot the printing nozzle, so this it what I got at the first trial.

but board and coding really gave me a hard time. I felt there’s still a lot of things I can improve this project and I surely will keep modifying it. This is just the very first prototype.

The whole pin ball table will be something look like this.

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