Difference between revisions of "TinyPS2"

From Land Boards Wiki
Jump to navigation Jump to search
 
(11 intermediate revisions by the same user not shown)
Line 29: Line 29:
  
 
[[file:TinyPS2_CPU_Rev4_Conns.PNG]]
 
[[file:TinyPS2_CPU_Rev4_Conns.PNG]]
 +
 +
<pre>
 +
#define DATAPIN 27
 +
#define IRQPIN  26
 +
</pre>
  
 
== Connectors ==
 
== Connectors ==
Line 47: Line 52:
 
[[file:TinyPS2_J2_Rev4_Conns.PNG]]
 
[[file:TinyPS2_J2_Rev4_Conns.PNG]]
  
=== H2 - In-System Programming Header ===
+
== Firmware Build Card Rev 4 ==
  
[[file:ICSP.PNG]]
+
[[file:asciifull.png]]
 
 
* SPI connector to download ATTiny85
 
* 2x3 header
 
* Program ATTiny85 without PS/2 keyboard attached
 
* Pinout
 
 
 
# KBCLK
 
# VCC
 
# SERTX
 
# KBDAT
 
# RST*
 
# GND
 
  
== Firmware Build Card Rev 4 ==
+
=== Arduino ===
  
 
* Card rev 4 uses a QTPy or XAIO RP2040 CPU
 
* Card rev 4 uses a QTPy or XAIO RP2040 CPU
 
* Arduino Library
 
* Arduino Library
 
** [https://github.com/techpaul/PS2KeyAdvanced PS2KeyAdvanced]
 
** [https://github.com/techpaul/PS2KeyAdvanced PS2KeyAdvanced]
* Example code built with warning
+
* [https://github.com/land-boards/lb-Arduino-Code/blob/master/LBCards/TinyPS2/TinyPS2_PCB_Rev4_AdvKbd/TinyPS2_PCB_Rev4_AdvKbd.ino TinyPS2_PCB_Rev4_AdvKbd] - code
 +
<pre>
 +
#define DATAPIN 27
 +
#define IRQPIN  26
 +
</pre>
 +
 
 +
* Example code produces warning
  
 
<pre>
 
<pre>
Line 75: Line 74:
 
Global variables use 43096 bytes (15%) of dynamic memory, leaving 227240 bytes for local variables. Maximum is 270336 bytes.
 
Global variables use 43096 bytes (15%) of dynamic memory, leaving 227240 bytes for local variables. Maximum is 270336 bytes.
 
</pre>
 
</pre>
 +
 +
* Code works well!
 +
 +
=== C++ ===
 +
 +
* [https://github.com/tvlad1234/pico-ps2Driv pico-ps2Driv] - SDK C code
 +
 +
=== CircuitPython ===
  
 
* CircuitPython support issues
 
* CircuitPython support issues
Line 85: Line 92:
 
ImportError: no module named 'ps2io'
 
ImportError: no module named 'ps2io'
 
</pre>
 
</pre>
 
== Firmware Builds Card Revs 1-3 (ATTiny85) ==
 
 
Two software builds:
 
 
* Scott Baker's build
 
* Arduino IDE port
 
 
=== Scott Baker's Software Build ===
 
 
* [https://www.smbaker.com/ps2-ttlserial-adapter-for-rc2014-and-midi Scott Baker's Build BLOG page]
 
* Scott's demo video
 
 
<video type="youtube">cSaBCtcUoq4</video>
 
 
* [https://github.com/sbelectronics/ps2-ttlserial Scott's GitHub page]
 
** Scott appears to have used [https://obdev.at/products/crosspack/index.html Crosspack] for AVR software development
 
* Scott uses two libraries from other projects
 
** [https://github.com/thegaragelab/tinytemplate ATTiny85 UART Library] - The Garage Lab
 
*** [https://github.com/thegaragelab/tinytemplate/blob/master/firmware/shared/uart_send.c uart_send.c]
 
** [http://www.nerdkits.com/videos/interrupts_and_ps2_keyboard/ Interrupts: Interfacing a Microcontroller with a PS/2 Keyboard] - PS/2 Keyboard Library
 
 
==== Programming Scott's Build ====
 
 
* Used [[TL866ii Plus Programmer]]
 
* Scott has [https://github.com/land-boards/lb-Arduino-Code/blob/master/LBCards/TinyPS2/ScottBakerCode/serkey.hex serkey.hex file]
 
** FUSES = -U lfuse:w:0x62:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m
 
** Used Fuse bits from  Programmer
 
*** Matched lfuse values already
 
 
==== Tested Scott's Build ====
 
 
* Works really well
 
* 115,200 baud
 
* Works at 3.3V or 5V
 
** Drops out around 3.15V - may need BOD bit changed?
 
 
=== TinyPS2 Software Build Using Arduino IDE ===
 
 
* Converted Scott Baker's build to the Arduino IDE
 
** Move main init code to setup()
 
** Move main inner loop to loop()
 
* Compiled fairly easily
 
* [https://github.com/land-boards/lb-Arduino-Code/tree/master/LBCards/TinyPS2/TinyPS2 GitHub Software Repo]
 
* Resources (Arduino UNO)
 
<pre>
 
Sketch uses 850 bytes (10%) of program storage space. Maximum is 8192 bytes.
 
Global variables use 15 bytes (2%) of dynamic memory, leaving 497 bytes for local variables. Maximum is 512 bytes.
 
</pre>
 
 
==== Setting Baud Rate ====
 
 
* The implementation is optimized for higher baud rates - please don't use anything below 57600 on an 8MHz clock
 
* It does work at up to 250000 baud but you may experience a small amount of dropped packets at that speed.
 
* Set in TinyPS2.ino file
 
<pre>
 
#define BAUD_RATE 115200
 
</pre>
 
 
==== Arduino IDE Setup for ATTiny85 ====
 
 
* [http://highlowtech.org/?p=1695 Programming procedure is taken from here]
 
* Add ATTiny Board support to Preferences, Path:
 
<pre>
 
https://raw.githubusercontent.com/damellis/attiny/ide-1.6.x-boards-manager/package_damellis_attiny_index.json
 
 
</pre>
 
 
==== Programming Card (Arduino IDE) ====
 
 
* Select ATTiny85, 8 Mhz
 
* '''Burn bootloader''' - Otherwise clock is way off
 
 
[[File:Arduino_IDE_ATTiny85.png]]
 
 
* [[ATProgHead]]
 
** Running Arduino as ISP
 
* Can program from an Arduino UNO like this:
 
 
[[file:ProgramFromArduinoUNO.jpg]]
 
  
 
== Schematic ==
 
== Schematic ==
Line 171: Line 98:
  
 
== Issues ==
 
== Issues ==
 +
 +
* [[TinyPS2_Revs_1-3|Revs 1-3 are documented here]]
  
 
=== Rev 4 ===
 
=== Rev 4 ===
Line 182: Line 111:
 
* CPU runs at 3.3VV
 
* CPU runs at 3.3VV
 
* 3.3V to 5V level shifter
 
* 3.3V to 5V level shifter
 
=== Rev 3 ===
 
 
* Added D3 to J1 connector
 
* Change from SMT parts to through hole parts
 
* Silkscreen cleanups
 
** Added ISP VCC/GND to silkscreen
 
** Added silkscreen to J1 pins
 
 
[[file:TinyPS2_Rev3_3D.png]]
 
 
=== Rev 2 ===
 
 
* Fixed issues below
 
 
=== Rev 1 ===
 
 
* Missing pull-up resistors on PS/2
 
** Rev 2 - add pull-up resistors
 
** (There's pullups in the part so this may not be needed)
 
* Missing C3 cap in sequence
 
** Rev 2 - change C4 => C3
 
  
 
== Assembly Sheet ==
 
== Assembly Sheet ==
  
* [[TinyPS2 Rev 3 Assembly Sheet]]
+
* [[TinyPS2 Rev 4 Assembly Sheet]]
* [[TinyPS2 Assembly Sheet|TinyPS2 Rev 1 Assembly Sheet]]
 

Latest revision as of 16:51, 15 August 2022

See TinyPS2 Revs 1-3 for ATTiny85 based build

TinyPS2 Front Rev4 3D.png

Introduction

It is getting difficult to find ASCII serial keyboards for use in Retro-Computer projects. This card fills that need. The card is a PS/2 keyboard to TTL Level Serial adapter. PS/2 keyboards are still widely available.

Keyboard PS2 MicrosoftNatural.jpg

Features

  • QT Py (RP2040 based)
    • Run at 125 MHz
    • 2MB of In System Programmable (ISP) flash
    • 264KB of SRAM
  • 115,200 baud serial
    • 57,600-250,000 are build time options
  • 49x49mm ODAS form factor
  • (4) 4-40 mounting holes
  • 3.3V or 5V operation
  • Current measurement
    • TBD @ 5V (without keyboard)
    • TBD @ 5V (including keyboard)
    • TBD @ 3.3V (including keyboard)
      • Does not require a keyboard that works at 3.3V

CPU Connections

TinyPS2 CPU Rev4 Conns.PNG

#define DATAPIN 27
#define IRQPIN  26

Connectors

J1 - TTL Serial Connector

TinyPS2 J1 Rev4 Conns.PNG

  1. VCC (pin nearest to J1 silkscreem)
  2. SERTX
  3. N/C
  4. GND

J2 - PS/2

  • Standard PS/2 Mini-DIN-6 connector

TinyPS2 J2 Rev4 Conns.PNG

Firmware Build Card Rev 4

Asciifull.png

Arduino

#define DATAPIN 27
#define IRQPIN  26
  • Example code produces warning
WARNING: library PS2KeyAdvanced claims to run on avr, sam, samd1, stm32, esp32 architecture(s) and may be incompatible with your current board which runs on rp2040 architecture(s).
Sketch uses 82336 bytes (0%) of program storage space. Maximum is 16777216 bytes.
Global variables use 43096 bytes (15%) of dynamic memory, leaving 227240 bytes for local variables. Maximum is 270336 bytes.
  • Code works well!

C++

CircuitPython

  • CircuitPython support issues
>>> import ps2io
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: no module named 'ps2io'

Schematic

Issues

Rev 4

  • Changed CPU
    • Was 8 MHz ATTiny85
    • Changed to QT PY or XAIO
  • Changed pin usage
  • Uses Hardware Transmitter in CPU
  • Keyboard runs at 5V
  • CPU runs at 3.3VV
  • 3.3V to 5V level shifter

Assembly Sheet