Tag Archives: electronics

Computer

Three display C64 audio monitor

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While I made this for my Commodore C64, it is applicable for many things.

It started with some cheap displays from Ali, and some leftover Wemos D1 from my Pressure Lab project.

I Started measuring the audio output from sound devices and from my C64.
I soon discovered that I needed some way to get the offset and amplification correct for the analogue input of a Wemos. (0-3v3)

So a little op-amp circuit was born, but not without some struggles.
I forgot many things about amplifiers. It was one of the first school books I got rid of. (Sorry mister Rafaela)

After searching the internet and posting a question on Reddit I ended up with the following.

R1 and R2 are 100M. The potentiometer P1 allows me to set the offset.
R3 is 1M
C1 is 100nF to decouple the audio signal from the RCA.

R4 is 47K and C2 is 330nF (thanks tycho205)
Cimportant=1/(2πfR2)
where f is the lowest frequency of interest. In this case Cimportant should be about 330nF

LM324 is a quad amplifier, leftover from another project.
Note, the SINGLE RAIL power.

P2 potentiometer is 2M (leftover) and gives me a variable amplifying opportunity.


A = Audio input

B = Setting the offset with P1

C = Setting the amplification

Below input signal (note negative values) above amplified signal with offset!

The displays are 3 Wemos controllers with a cheap I2C display.
These are just fast enough to do FFT.

Analogue in is the output from the OP-amp offsetter ..

CODE

Needs cleaning up, and a better stabilizing routine.

3dprinting, Art, Computer, Tech

Busy .. work and play

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While working on my clients projects, I’ve been busy with other Fun stuff.

All will be posted more about soon

  • Designing 3D models for printing
  • Testing Arduino Code for RS485!
  • Creating T-shirt prints using 3D printing and bleach/paint with Vincent !
  • Transforming my Lab
  • Testing UM25C logging possibilities
  • Testing queries on overpass-turbo.eu (So much fun)
  • Playing chiptune music using Synthcart + Midi
  • Made V2 displayer on my 64×64 HUB75 led display
  • Bought a directional Wi-Fi antenna, tweaking wireshark to pinpoint rogue access points and clients.

3dprinting, Computer, IOT / Domoticz / Home Assistant

March stuff, being busy

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Working for clients, so fragmented personal stuff.
New workplace setup so even more space!

My BBQ monitor V3

As posted before, but now an esphome version, with big-ass buzzer

Code available soon, when made generic.

4Button controller using ESPHOME

Code allready posted

STL FILE https://media.henriaanstoot.nl/4buttons.stl

Flash trick for XYUSB

Flashing this to ESPHOME, use sowing pins!

CODE

substitutions:
  name: usb-relay
  friendly_name: "USB Relay"
  default_state: "RESTORE_DEFAULT_OFF"


esphome:
  name: xyusb1
  friendly_name: xyusb1

esp8266:
  board: esp01_1m

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: "ndm8xxxxxxxxxxxxxxxxxjlvrggJv3a1BkY="

ota:
  - platform: esphome
    password: "12cc9xxxxxxxxxxxxxxxxfb6a01e672"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Xyusb1 Fallback Hotspot"
    password: "xxxxxxxxxxx"

captive_portal:

time:
  - platform: homeassistant

# Blue LED
status_led:
  pin:
    number: GPIO16

# Relay
switch:
  - platform: gpio
    id: switch_relay
    pin: GPIO5

  # Green LED
  - platform: gpio
    pin: GPIO14
    id: green_led
    inverted: true # start on

  # Switch template to link relay and green LED states
  # LED is on when relay is off
  - platform: template
    id: relay
    name: "${friendly_name}"
    lambda: |-
      if (id(switch_relay).state) {
        return true;
      } else {
        return false;
      }
    turn_on_action:
        - switch.turn_on:
            id: green_led
        - switch.turn_on:
            id: switch_relay
    turn_off_action:
        - switch.turn_off:
            id: green_led
        - switch.turn_off:
            id: switch_relay

# Button
binary_sensor:
  - platform: gpio
    id: hardware_button
    pin:
      number: GPIO04
      mode: INPUT_PULLUP
      inverted: True
    on_press:
      - switch.toggle: relay

# WiFi Signal Sensor
sensor:
  - platform: wifi_signal
    name: "WiFi Status"
    update_interval: 60s

# Restart button
button:
  - platform: restart
    name: "Restart"

Reflashed my USB Volume button and added a LED-Ring.

Example is green and blue.

Funny text on box

What is a termianl assortment? LOL

Wireless Temperature/Humidity sensor for ESPHome.

Wemos D1 mini with deep sleep, voltage monitoring using A0 line.
BME280 Temperature/Humidity sensor.
And a 18650 battery with TP4065 battery manager.
Now 3D print a little case.

Made a PCB for a 24 Channel Logic analyzer

See post:

24 Channel Logic Analyzer using Pico and Levelshifters
PCB Design
Computer

68000 Progress

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UPDATE 20240927 PCBs are in

While testing on a breadboard is fast, I still want my 68000 on PCBs.

Breadboards are nice for testing, and I use them in the design stage.
But they will fail in the end.
Loose wires, oxidated contacts and alike.

So when I was testing using breadboard, I drew the schematics in KiCad.

I wanted to use Eurocards for this one. If I divide the whole system in system blocks, I can exchange and experiment parts.
(My 6502 uses another method to connect different cards)

  • CPU and Clock (Plus power-on reset and step mode)
  • Memory and ROM
  • Storage
  • Address decoding
  • Sound
  • IRQ Handlers
  • Led Blinkenlights 🙂
  • …

I wrote about Eurocards in the past.

Eurocards

So I’m using the VMEbus standard for my new design.
(Using the recently bought book I mentioned)

Backplane design is done. And currently being autorouted.

PowerLeds for 5 and 12V. On/Off switch and MOLEX power connector.

Kicad sources will be uploaded

Freerouter with in the background a part of the CPU Card I am redesigning.

In the past, I dumped my old eurocards and even a nice case I had.

UPDATE 20240927 PCBs are in

Computer, IOT / Domoticz / Home Assistant

Reverse engineering Newton wars, giving it my own twist.

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Saw a cool game a while ago, and found some old code.
There was no schematic, so I had to reverse engineer it using the Arduino code.
This one uses a Micro Pro.

Build a working version, now I can use this as base to create other games.
But first i’m going to rebuild it so it can use Wifi and uses a Lipo Battery. Making it usable without wires.

  • Rotary – set angle/speed (Press resets)
  • Blue – toggle angle or speed ( was rotary press )
  • Green – select digit to change
  • Red – Fire
  • Led – not completely working yet, shows color of player
    Wil be changed to addressable leds with more functions
    (Player color, energy warning and more)

Next to do:

  • Build a Wifi version with Lipo
  • Build permanent version in a case
  • Build 2nd 3th or more controllers
  • Create own games