Tag Archives: hardware

Computer

7 segment displays/keyboard decoders in SDK’s

There are a lot of old develop boards for all kinds for cpu’s.

These where build to learn machine code programming. Mostly made in the 80’s, and based on populair cpu’s at that time.

I own a some of these SDK’s (System Design Kits)

8085 – SDK85 i bought recently 8085 CPU
Microprofessor-1 (MPF-1) Z80 CPU
And my own 680x based computer

Most of these use a keyboard scanner which is also connected to 7 segment displays.

The way they work is practically the same. There is a VIA or PIA. Versitile interface adaptor, or Peripheral interface adaptor. These have two times 8 bits to control devices.
When using 4 bits and convert these to 16 lines by using a 75ls145 for example. If you put a counter on those 4 bits, you sequently activate 1 of 16 lines. These lines you can use to scan a keyboard matrix OR display a character on a 7 segment display. These display’s won’t hold the data (and show the character) when not activated. The trick is to update de display fast enough so you don’t see the flickering on/off.

Activate a line and read a byte with the VIA = Reading keyboard row
Activate a line and write a byte with the VIA = Display on a segment

These VIA/PIA’s where made with specific timings to match the CPU.
6522/6820/8255

Below you see some different implementations of these keyboard/display combo’s

Thaler 6502 kit
Microprofessor MPF-1 kit (ignore red circle)
SDK85 kit
Eltec 6800
My version using darlington arrays (ULN2003)

When looking at the 8085 version you see transistors being a ULN2003 is a chip with those transistors/amplification enclosed.
It doesn´t draw much current from the bus, and diodes protect the way the current flows.

Computer

Generic Matrix Keyboard Print

I only have to check my new design for a generic matrix keyboard once again, and then i’m going to order a few of these prints.

  • 32 keys (2 blocks of 16)
  • 1 key is changeable from generic key to reset signal key
  • jumper header connector VCC, GND, DataAvailable, Reset and 5 data lines

I’ve used the opensource tool freeroute to autoroute the coppertraces

  • From Kicad export PCB in Spectra DNS format
  • Open Freeroute and run autoroute
  • export as Spectra Session File
  • In kicad import this session file again

Autotraced …
Front
Back
Current setup

TODO: Look into charlieplexing ! For input and Led control

Computer, IOT / Domoticz

Raspberry and SSD

I had a crash recently on one of my raspberry-pi’s ..
SDcard failure, they are not made for a lot of write actions.
In the past i’ve changed some images to read only and with a r/w overlay.
Also tmp filesystems in memory .. all not ideal.

So i’ve started to make every RPi ssd bootable.

I’ve got several ssd already from other projects.
Sata to USB adaptors are cheap, only a few euro’s.

Steps to take:

  • Download Raspberry Pi Imager tool
  • Choose OS > Misc Utility Images > Bootloader > USB Boot
  • Select storage and write to a temporary sd-card (Not needed any more after flashing for normal operations)
  • Boot USB with this Micro-SDcard .. i didn’t have a screen connected .. So i just waited a few minutes
  • While i was waiting i wrote a OS image to the SSD using the same imager tool
  • Choose OS > select sata/ssd drive
  • Change options (cog), enable ssh, choose hostname and set password
  • Write to drive
  • Remove sdcard from RPi attach ssd/sata and boot

My 3D printed sdcard case, luckily there was still one in there (32GB kindda big, but it was only for temporary use .. 16GB was broken ..

So .. without attaching a screen or keyboard, just a network cable. I have a running OS on a RPi from SSD

Computer

SDK-85 in 2022

I was posting about the 8085 System Design Kit in may, but now i’ve got one!

8085 Machinecode at school

I found one online, it is a very clean almost like its never been used version!

And it works .. !
Some schematics (more in the books)
1978 Manual
Program i used to test above
Assembly manual (many pages)

More follows!

More info at http://www.bitsavers.org/components/intel/8085/

Art, Computer

3DMouse and blender

UPDATE: 2022-09-29

Yesterday i got two 3DConnexion 3D CAD mouses (mice) from my friend Vincent. While we where fixing his Mikrotik network i got to play with these cool devices.

I always wanted one of those, but they are quite expensive

First i tried to install the Software from 3DConnexion. It kindda worked but needed some workarounds and still wasn’t okay.

Downloaded 3dxware-linux-v1-8-0.x86_64.tar.gz (Maybe this version is TOO new, SpacePilot i a little ouder)
there is a install-3dxunix.sh, but it was made for Suse/Redhat

This program needed motif .. and a lot of libraries (libmotif/libxm)
After that some fonts xfonts-100dpi xfonts-75dpi


workaround was starting by 
sudo /etc/3DxWare/daemon/3dxsvr -userName ${USER} -d usb

After that the demo program worked perfectly … but Blender didn’t
After some tinkering it work a little, it was far to sensitive, and was all over the place.

Luckily i found a opensource replacement. https://spacenav.sourceforge.net/
git cloned the package, then i notished .. there is a precompiled version for ubuntu!

apt-get install spacenavd .. start the service .. and go!

i cloned the test demos (libspnav) and compiled those test programs.

apt-get install libglu1-mesa-dev
git clone https://github.com/FreeSpacenav/libspnav.git
cd libspnav
./configure
make
... fly is a nice little test program

So lets start blender

Pan tilt roll .. nice!

This wil speedup modeling, and for sure sculpting !

Some settings which worked for me .. let the tweaking begin!

UPDATE: 2022-09-29

I removed the version in the apt repository, and installed everything from git. Now i have a cool configure tool

IOT / Domoticz

Homewizard Watermeter

Today i got my watermeter in.

It’s a little device you can place on your watermeter.

You get a plastic clip/holder which you can use to place the device on your watermeter. You can easily remove the device to read the values.

The device measures the little round gauge, so it has no idea what the current values are. Add the current values of your meter to the output of the device.

The device works by measuring the rotation of the red part.

By default it sends the information over the internet to a server. Your phone connects to this server and the app wil give you the graphs.

If you want your own intergration, you have to enable “local api”
See image on the right.
When you want realtime data, you have to connect a usb-c power supply.
When using batteries, the device wil only connect to wifi once per 5 minutes, and you can’t use the API.

I wrote a little test script in bash to draw graphs using mqtt and Nodered.

#!/bin/bash
calib=29.621
data=$(curl -s http://10.1.1.176/api/v1/data)
totalwater=$(echo $data | cut -f9 -d\" | tr -d ':,')
currentwater=$(echo $data | cut -f11 -d\" | tr -d ':,}')
totalwater=$( echo $totalwater + $calib | bc)
mosquitto_pub -h 127.0.0.1 -m "$totalwater" -t watermeter/total
mosquitto_pub -h 127.0.0.1 -m "$currentwater" -t watermeter/current

Variable calib is what my watermeter was when i attached the device.
It wil add this to the newly measured values.

Home Assistant found the device using autodiscovery

I have to look into adjusting for offset in HA

Computer

6502 update

  • New amplifier part using a LM386
  • Buzzer and led on VIA 2, blinky and sound timed by the internal timers of the 6522
  • ACIA testing still going on, writing software
  • Mini matrix keyboard removed, and used the temporary cursor buttons for the test with a rom which allows for a 8bits upload method using a arduino and the 6522. (I’m working on the big keyboard)

Work in progress code

PORT2B = $5000 		; VIA PORTB
PORT2A = $5001 		; VIA PORTA
DDR2B = $5002  		; Data direction register
DDR2A = $5003  		; Data direction register

PORTB = $6000 		; display
PORTA = $6001 		; control display + matrix keyboard
DDRB = $6002  		; data direction register
DDRA = $6003  		; data direction register
SID = $7000   		; sid base address

E  = %10000000		; enable bit
RW = %01000000		; RW bit 
RS = %00100000		; Register Select bit 
HOME = %00000010 	; VIA PORTB HOME command
DADDR = %00010000 	; VIA DADDRESS

LINENO = $0200		; temp address linenumber (move to other location)
NEXTLINE = 40		; 2x16 Chars but internally 40


  .org $8000

reset:
  ldx #$ff
  txs		; reset stack

; ###################################################
; #                 DISPLAY CONTROL                 #
; ###################################################
; VIA Setup

  lda #%11111111 	; Set all pins on port B to output
  sta DDRB
  lda #%11100000 	; Set top 3 pins on port A to output
  sta DDRA

; DISPLAY Setup
  lda #%00111000 	; Set 8-bit mode; 2-line display; 5x8 font
  jsr lcd_instruction
  lda #%00001110 	; Display on; cursor on; blink off
  jsr lcd_instruction
  lda #%00000110 	; Increment and shift cursor; don't shift display
  jsr lcd_instruction
  lda #$00000001 	; Clear display
  jsr lcd_instruction

; ###################################################
; #             PRINT MESSAGE LINE NO 0             #
; ###################################################
  lda #0  		; set line number
  sta LINENO      	; store for subroutine
  jsr gotoline		; move cursor

  ldx #0		; message index pointer
print:
  lda message0,x 	; start of message
  beq nextprint      	; stop when null in message (asciiz <- Zero padded)
  jsr print_char	; print char
  inx			; incr index
  jmp print		; resume print
; ###################################################
; #             PRINT MESSAGE LINE NO 1             #
; ###################################################
nextprint:
  lda #1  		; set line number
  sta LINENO      	; store
  jsr gotoline
  ldx #0  		; index pointer                 
print2:
  lda message1,x  	; absolute address message + x in A
  beq sidsound        	; if x is 0, end of message     
  jsr print_char  	; jump subroutine
  inx             	; increment x
  jmp print2      	; loop print2



; ###################################################
; #             SID SOUND                           #
; ###################################################
sidsound:
  lda #0		
  sta SID+$5		; attack/decay duration
  	
  lda #250
  sta SID+$6		; sustain level/release duration
  	
  lda #$95		; frequency voice 1 low byte
  sta SID+$0
  	
  lda #$44		; frequency voice 1 high byte
  sta SID+$1
  
  lda #%00100001	; sawtooth + gate
  sta SID+$4		; control register voice 1
  
  lda #$0f		; filter mode and volume (bits 3-0 main volume)
  sta SID+$18		; filter mode and volume



; ###################################################
; #             2ND VIA                             #
; ###################################################
  lda #%11111111 	; set port A output
  sta DDR2A

  lda #%11111111	; all ones!
  sta PORT2A
; ###################################################
  lda #%11111111 	; set port A output
  sta DDR2A

  lda #%11111111	; all ones!
  sta PORT2A



; ###################################################
; #             MAIN PROGRAM LOOP                   #
; ###################################################
loop:
  jmp loop
;                   1234567812345678
message0: .asciiz  "VIA 1,2 SID TEST"
message1: .asciiz  "   FASH  2022   "

; ###################################################
; #             ONLY SUBROUTINES                    #
; ###################################################

; ###################################################
; #             Subroutine gotoline                 #
; # Moves character placement position on display   #
; # Needs : $LINENO ADDRESS                         #
; # Exit values : -                                 #
; # Destroys registers: -                           #
; ###################################################

gotoline:
  pha                             ; store a
  txa
  pha                             ; store x
  ldx LINENO
  lda #HOME                       ; cursor down
  jsr lcd_instruction
  lda #$80
nextline:
  ldx LINENO
  cpx #00
  beq endnextlines
loopline:
  adc #40
  jsr lcd_instruction
  dex
  stx LINENO
  jmp nextline
endnextlines:
  pla                             ; pop a
  tax                             ; a to x
  pla                             ; pop a
  rts




; ###################################################
; #             LCD SUBROUTINES                     #
; ###################################################
lcd_wait:
  pha
  lda #%00000000  ; Port B is input
  sta DDRB
lcdbusy:
  lda #RW
  sta PORTA
  lda #(RW | E)
  sta PORTA
  lda PORTB
  and #%10000000
  bne lcdbusy
  lda #RW
  sta PORTA
  lda #%11111111  ; Port B is output
  sta DDRB
  pla
  rts
lcd_instruction:
  jsr lcd_wait
  sta PORTB
  lda #0         ; Clear RS/RW/E bits
  sta PORTA
  lda #E         ; Set E bit to send instruction
  sta PORTA
  lda #0         ; Clear RS/RW/E bits
  sta PORTA
  rts
print_char:
  jsr lcd_wait
  sta PORTB
  lda #RS         ; Set RS; Clear RW/E bits
  sta PORTA
  lda #(RS | E)   ; Set E bit to send instruction
  sta PORTA
  lda #RS         ; Clear E bits
  sta PORTA
  rts

nmi:
  rti

irq:
  rti

  .org $fffa
  .word nmi
  .word reset
  .word irq
;  .word $0000
Computer

So i wasn’t being stupid designing a dual matrix keyboard thingy

As previously posted, i had an idea to create a dual matrix keyboard mashup using available components.

I mentioned that “it should theoretically work”. But only being using atf22v10c for a couple of days. It was a long shot.

I’ve put it to the test .. and it worked first time.

I can use above, to connect my extended matrix keyboard to a 6522 VIA chip using 5 pins and sending a data available signal to CA1.

This keyboard i was planning to use
Computer

Generic matrix keyboard

In this case designed for my 6502, but it is a generic setup.

I it just a dual 16key matrix decoder merged together. You can probably use this with raspberries, arduinos etc.

I wanted to use 74C923 but these are nowhere to be found. And even then, the number of keys wil be 20.
So i am tying together two 74C922 using some logic in a PLD.

First draft

It wil be something like above. Using the data availabe signal i can combine both 16key matrixes. (In theory .. it is all untested)

PLD Code

GAL22V10
Address Decoder

PHI2 DA0 DA1 D01 D02 D03 D04 D11 D12 D13 D14 GND
NC D0 D1 D2 D3 D4 DA NC NC NC NC VCC

DA = DA0 + DA1
D0 = D01 & DA0 + D11 & DA1
D1 = D02 & DA0 + D12 & DA1
D2 = D03 & DA0 + D13 & DA1
D3 = D04 & DA0 + D14 & DA1
D4 = DA1 

DESCRIPTION
Key matrix merger

I’ve got my new keys of the keyboard in today!

  • 0-F – hex keys
  • G = Go
  • R = Reset
  • S = Step
  • M = Memory
  • Cursor keys (up/down for memory locations)
  • ??? I’ve got room for 8 more keys

My inkscape template (keys are 10/10mm)

Printed on white and red paper

https://media.henriaanstoot.nl/keyboardmatrix.svg