Category Archives: 3dprinting

Mikrotik Wifi, 80386 and Lilygo streaming

Quiet days, I working on some art.

But here are the last ‘prutsen’

My current Wifi setup

I’ve got a Wifi outside of my network for guest and emergency. ( 2 SSIDs)

Then a main Wifi router in my livingroom, one in my workshop/studio and one in the Attic (Electronics Lab)

So three main Wifi AccessPoints. These all have the same SSID’s but on different frequencies. That way i’ve got roaming in and outside my house.
Also some virtual accesspoints are configured.
I’ve got a main, folkband, IOT, guest-inside all on 2.4Ghz and 5Ghz.

I watched a lot of YT presentations about Mikrotik Wifi.

So I ended up with DFS safe channels 20Mhz for 2.4 and 20/40Mhz Ce for 5Ghz. (subchannels for each after some frequency scanning)
(2.4 does a failback to 20Mhz whenever there is even one client detected which connects only on this band. Such as some old IOT stuff)
2.4 in only 1,6 and 11 no overlap, each on another device.
300Mbps is sufficient for my wifi 🙂

I’ve got accesslists in place and i’m going to read into kicking a client when the signal strenght is below -50dB

80386 (DX) Computer

Besides my 8088 and 8086 machines I needed a machine which could run our old demo’s. So I bought a new toy.

It has 8Mb Ram and runs at 40Mhz.

I’ve noticed that many of my VGA register manipulation code, can’t be run on a modern VGA monitor, I need to use a CRT for that .. Another thing to buy

Lilygo T-Display S3 Streaming

Not my code:
A very cool project!

Needed to fix arduino code, due to the TFT_eSPI library issues.
And I’ve got a S3 with another resolution, but that was an easy fix.
Then needed to reinstall nodejs with another version.
Had to modify the code because the tcp server would not start.
Weird errors logging, but in the end fixed … very cool

I probably end up designing a 3D printed case that looks like a monitor or tv.

3D printing problem and Fluxengine

3D printed a case for my fluxengine.

Last week I got my 1.2MB 5.25″ drive.
And tested it with the fluxengine.
Now i can read old 5.25″ disks again. And convert these to disk images.
Amiga/Atari ST/C64 (single side) and my old MSDos disks.
(That’s what I’m using, the fluxengine can read many more)

Why single side C64? you ask?
Those are flippy disks, that means they are single sided and you flip the disk in the drive to read the other side.

Why can’t the fluxengine read those?

  • There is only one sensor in my drive.
  • Reading side 2 without turning the disk won’t work, the sectors are in reverse!
    (Maybe there is a trick to read in reverse? Fluxengine is reading and decoding raw disk sectors, but i have to read into this)

Note: The 1541 Drive for the commodore’s is a complete 6502 computer with 2x 6522 VIA and ram/rom chips! (2016-15 2K x 8 bit Static RAM / 27128 16kb x 8)


And this amazing trick:

Maybe i’m going to modify my 5.25 drive with another index sensor.

So i downloaded a diskdrive case from thingiverse, which can hold 2 drives. 3.5″and 5.25″.

I started printing the bottom, no problem there. But because of the large size of bottom and top. (Both about a day of printing) I had to change the filament.
But I didn’t have a good look at what I took!
Below is what you get when printing PLA and switch to PETG!

Temperatures for PLA:
Tool: 200 and bed 50
Temperatures for PETG:
Tool: 240 and bed 70

So 12 hours printing and I had to start again.

I could not remove the knob, else I would have removed the beige front and spray painted this black.

Finished a display case for the SDK-85

So i made a nice display case for this SDK.

I made some designs and came up with this:

I just took a 12mm x 60mm piece of wood, and made a slit for the acrylic plastic using a circular saw, and removed a part for the back-plate using a wood router. I found a piece of acrylic in my shed, cut it to the right size using the circular saw. Slapped some paint on the wood.

I want to be able to use the sdk whenever i want, so i made a sliding window thingy. ( With wooden handle so the frame looks intact when closed. )

Then I 3D printed some holders, which I designed using Openscad.

Openscad code


    cylinder(h=9, d1=9, d2=9, center=true);
cylinder(h=9, d1=15, d2=15, center=true);
 cylinder(h=30, d1=3.5, d2=3.5, center=true);

I will probably add a powerconnector and lasercut a hole for the keypad at a later stage.

Made a case for my page turner

Using OpenScad I ended up with this .. a nice minimal design

Openscad file (Jup thats all)


cube([96,30,12],center = true);
cube([15,30,23],center = true);
cube([15,30,23],center = true);
cube([90,30-6,24],center = true);
cube([90,20,30],center = true);
cube([77,20,35],center = true);

Clay press to make a brick wall (for models)

I found a nice tile-able image on the internet to make into a clay press.

UPDATE: 20230406

Using Blender and 3D printing, I’ve got this result.

Take a flat image an convert to black-white. Then invert!

Create cylinder in blender.
Change capfill into nothing, and set sizes.
Add modifier: Solidify
Add texture
CTRL-R and divide, then subdivide
Subdivide surface
Add displace modifier.
Texture coordinates UV.
Displacement negative 0.1-0.3

UPDATE: 20230406

I need to apply the white/gray first in all cracks, and the red color is a little off.

Playing with lasercutter steppermotors

Busy day: I’ve airbrushed some 3D pieces a few days ago, but i need 50 or so more.
Meanwhile is was reinstalling octoprint, and making a new version of my Bluetooth page flipper. (Android Music Sheet Pedal Thingy. Which i also didn’t post apparently)
But the main project was this:

I was curious how fast the stepper motors are on my laser cutter. And for what can we utilize this!

So I took a Raspberry Zero and some rotary encoders, lets make an etch-a-sketch like thingy.

Some rotary encoder modules I had.

Next to do: 3D print a pen holder, and alter the code to enable the laser when moving!


Below code uses a simple rotary class, and generates control GCodes for the steppers/Sculpfun

import time
import serial
import RPi.GPIO as GPIO
from encoder import Encoder

def valueChanged(value, direction):
    print("* New value: {}, Direction: {}".format(value, direction))


e1 = Encoder(20, 21, valueChanged)
e2 = Encoder(16, 12, valueChanged)

x = 0
y = 0
arduino = serial.Serial('/dev/ttyUSB0', 115200, timeout=.1)

newx = 0
mystringx = ""
newy = 0
mystringy = ""

arduino.write(str.encode("G00 G17 G40 G21 G54\r\n"))
arduino.write(str.encode('G0 X41.5Y36.05\r\n'))
arduino.write(str.encode('G1 X2.5F6000S0\r\n'))
arduino.write(str.encode('G1 X0\r\n'))
arduino.write(str.encode('G1 Y0\r\n'))

    while True:
        data = arduino.readline()[:-2] #the last bit gets rid of the new-line chars
        if data:
                print (data)
        arduino.write(str.encode("G1 F10000\r\n"))
        newx=e1.getValue() *5 + 100
        newy=e2.getValue() *5 + 100
        mystringx=f"G1 X{newx}\r\n"
        mystringy=f"G1 Y{newy}\r\n"
#        print(mystringx)

except Exception:


SG90 servo Arm generator in OpenScad

SG90 Servo
Adjust the arm lenght using the slider, export to STL and print!

Openscad can be found here

Openscad source

sliderWithMax =40;  // [80]

	difference() {
		union() {
				difference() {

					hull() {
						circle(d=6,$fn = 100);
						translate([sliderWithMax-2,0]) circle(d=4,$fn = 100);

					translate([4,0]) for (i=[0:sliderWithMax/2-3]) translate([i*2,0]) circle(d=1,$fn = 100);
			cylinder(d=6.7, h=3.8, $fn=100);
		translate([0,0,-1]) cylinder(d=2.5, h=3.8+2, $fn=100);
		translate([0,0,-1]) cylinder(d=4.7, h=1+1, $fn=100);	
		translate([0,0,3.8-2+1]) cylinder(d=4.7, h=2+1);	

Screens and DIY projects

Below some examples and connection diagrams to control displays.
More code and complete schematics will be added on this page or on a separate projects page.

UPDATE 20230119 Cost of 20×4 display in 1998


I’ve used a LCD display like this (HITACHI HD44780) on my PC in the 90s, and also written code to use this as a monitoring device on my amiga.

On Linux i used LcdProc – This module also was equiped with a serial connector
Now (2023) it is 8 euros!
;LCD Display Module             Parallel port
;        1 Vss                  20 GND
;        2 Vdd                  14 +5V
;        3 Vlc                  20 GND (contrast LCD display)
;        4 RS (register select) 11 BUSY
;        5 R/W                  12 POUT
;        6 E (enable)           13 SEL
;        7 DB0                   2 D0
;        8 DB1                   3 D1
;        9 DB2                   4 D2
;       10 DB3                   5 D3
;       11 DB4                   6 D4
;       12 DB5                   7 D5
;       13 DB6                   8 D6
;       14 DB7                   9 D7
Amiga code part
        bsr     initprt         ; CIA 8520 init
        bsr     initlcd         ; init lcd display module
        move.l  #0,d0

initprt:move.b  #$ff,$bfe301    ; parallel port is output
        move.b  $bfd200,d0
        ori.b   #$07,d0         ; select, p-out and busy
        move.b  d0,$bfd200      

initlcd:move.w  #$38,d0         ; multiple reset
        bsr     send
        bsr     delay2
        move.w  #$38,d0
        bsr     send
        bsr     delay2
        move.w  #$38,d0         ; 2*8 lines
        bsr     send
        bsr     delay2
        move.w  #$01,d0         ; clear display
        bsr     send
        bsr     delay2          ; wait
        move.w  #$0c,d0         ; display on
        bsr     send
        move.w  #$06,d0         ; Entry Mode Set
        bsr     send

send:   bsr     delay
        btst    #8,d0           ; test rs bit
        beq     reg0
        bsr     rs1             ; select register 1
        bra     skip
reg0:   bsr     rs0             ; select register 0
        bsr     delay
        bsr     rw0             ; read/write=0 
        bsr     delay
        bsr     e1              ; enable = 1
        bsr     delay
        move.b  d0,$bfe101      ; push data
        bsr     delay
        bsr     e0              
        bsr     delay

delay:  move.w  #$20,d1
dloop:  subi    #1,d1
        bne     dloop

delay2: move.w  #$800,d1
dloop2: subi    #1,d1
        bne     dloop2
Part of my MQTT display alarm thingy
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>  
LiquidCrystal_I2C lcd(0x27, 20, 4);
const char* ssid = "MYACCESSPOINT";
const char* password = "MYPASSWORD";
const char* mqtt_server = "mymqttserver";
const byte ledRed = 12;
const byte horn = 13;
int button = 2;
int press = 0;
boolean buttonToggle = true;


WiFiClient espClient;
PubSubClient client(espClient);
bool toggle = false;
void setup_wifi() {

  Serial.print("Connecting to ");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED)
  Serial.println("WiFi connected");
  Serial.println("IP address: ");

void callback(char* topic, byte* payload, unsigned int length)
  if (length > 0) {
    toggle = true;

  if (length == 0) {
    toggle = false;

  Serial.print("Command from MQTT broker is : [");

  Serial.print(" publish data is:");
  lcd.backlight(); // turn off backlight

    for (int i = 0; i < length; i++)
      if (i < 16){
      lcd.setCursor(0, 0);
      lcd.setCursor(i, 0);
      } else {
      lcd.setCursor(0, 1);
      lcd.setCursor(i-16, 1);


void reconnect() {
  while (!client.connected())
    Serial.print("Attempting MQTT connection...");
    String clientId = "mqttlcd";
    clientId += String(random(0xffff), HEX);

    if (client.connect(clientId.c_str()))

    } else {
      Serial.print("failed, rc=");
      Serial.println(" try again in 5 seconds");

void setup() {
  pinMode(button, INPUT);
  digitalWrite(2, HIGH);
  pinMode(ledRed, OUTPUT);
  digitalWrite(ledRed, LOW);
  pinMode(horn, OUTPUT);
  digitalWrite(horn, LOW);
  client.setServer(mqtt_server, 1883);

void loop() {

  if (!client.connected()) {
  if (toggle == true) {
    digitalWrite(ledRed, HIGH);
    digitalWrite(horn, HIGH);
    digitalWrite(ledRed, LOW);
    digitalWrite(horn, LOW);
  if (toggle == false) {
    digitalWrite(ledRed, LOW);
    digitalWrite(horn, LOW);



  press = digitalRead(button);
  if (press == LOW)
    if (buttonToggle)
      digitalWrite(ledRed, HIGH);
      digitalWrite(horn, HIGH);
      buttonToggle = !buttonToggle;
      digitalWrite(ledRed, LOW); 
      digitalWrite(horn, LOW);
      buttonToggle = !buttonToggle;
      toggle = false;
      lcd.noBacklight(); // turn off backlight
  delay(500);  //delay for debounce


There are several oled displays, mostly controllable with i2c but some of them are SPI

SSD1306 – I2c connected

Using a wemos – Octoprint project for example
Octoprint (Note: this is NOT a multicolor display 1/4 of the display is yellow. )
My notification watch. Runs on a ESP12F connects to Wifi, has a piezo sound element
Using a raspberry (Part of my Lab Sensors Project)
pip3 install adafruit-circuitpython-ssd1306
git clone (old)
Edit file - comment SPI section

Some arduino’s have embedded displays like those i’ve used for a Lora project.

Other means of connecting : SPI

SPI connected display


Nextion is a Human Machine Interface (HMI) solution combining an onboard processor and memory touch display with Nextion Editor software for HMI GUI project development.

Using the Nextion Editor software, you can quickly develop the HMI GUI by drag-and-drop components (graphics, text, button, slider, etc.) and ASCII text-based instructions for coding how components interact on the display side.

Nextion HMI display connects to peripheral MCU via TTL Serial (5V, TX, RX, GND) to provide event notifications that peripheral MCU can act on, the peripheral MCU can easily update progress, and status back to Nextion display utilizing simple ASCII text-based instructions.

My nextion domoticz box, tilt to wakeup
Domoticz controller

My biltong box using a Nextion

Raspberry displays

 3.5inch RPi Display – 480×320 Pixel – XPT2046 Touch Controller
edit cmdline.txt
add "fbcon=map:10 fbcon=font:ProFont6x11 logo.nologo"
at the end
edit config.txt
add between custom comments at the bottom
# Or check

Above display’s i’ve used for Picore Players and the Lidar POC

To try: Getting above display running with a arduino

Raspberry HDMI display

Easiest of them all, just connect with HDMI, there is a adaptor for hdmi-hdmi (versions 1,2,3) and hdmi-mini-hdmi for RPi4 variants.

Epaper and 7-Segment displays

Other means of displaying information are for example


ESP with epaper module, disconnected power for a while, artifacts appear.

7 Segment displays

I used a lot of 7-Segment display’s in the past. They look cool and are hardcore.

My homebrew computer uses this

Nixie tubes!

And there are .. I’ve never had those

Above bigger 2D display i used with Wled and a digital microphone, so its sound reactive. The lower part i got in recently .

inmp441 digital microphone

PCB Holder, flashing door sensors

A while back i printed a PCB holder, perfect for accessing contacts on a print, without the need for soldering.

Flashed a doorsensor with Tasmota. --port /dev/ttyUSB0 write_flash -fs 1MB -fm dout 0x0 tasmota.bin

Keep GND and VCC connected, to keep device awake. Else it’s going into sleep mode.

Pull GPio0 to GND @ boottime, to get into flash mode.

3v3 + GND to keep device alive for configuring.

TTL Uart with 3V3