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Tachyon thread on Propeller forum

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An earlier demonstration using the serial console and VGA demo


Compile from on-line source, load extensions and AUTORUN


Taken from real paying projects - not just examples

NFC card reader and calendar timer interface for eletronic gate opener

Process control with remote VGA screens + keypads to measure volume pours.

Force sense resistor processor (used on robot gripper arms)

Source code

Use this latest version

The original formatted live source code document for V1 (obselete)

Spin Tool compilers

Use this to compile the PASM kernel to bring Tachyon to life

Brad Campbells excellent Spin/PASM compiler - yet to be beaten

The standard Spin/PASM compiler from Parallax

Tachyon Forth software

Suggested build

Here is a list of files in order that I use to build a complete system. The minimum are the Tachyon kernel and EXTEND. If you have a hardware header you can set it up similar to this QuickStart so that any extra modules that are loaded use the correct pins by default vs runtime setup.

The SDCARD and EASYFILE files are very useful for an SD work and of course if you are into Ethernet and happen to have a WIZnet chips then the last two modules will get you going with FTP and TELNET, and WEB server. Configure these interactively while it's operating.

Header files for various PCBs

Load an optional header file in after EXTEND.fth to automatically configure any modules loaded afterwards.

DropBox binaries etc for various configurations

General Forth source extensions to add to the kernel

Iincludes I2C.fth + BACKUP plus lots of goodies

Spin modules

Spin code for 3M baud+ serial receive object  (including in Tachyon source)

Original Spin/PASM bitmap driver from Chip

Project page links


SPLAT - the Serial Propeller Logic Analyzer Terminal

sample 32 channels of I/O and display it on your ANSI serial terminal


 FTP, TELNET, HTTP servers for the WIZnet chips (coming soon)

Latest WIZnet chip - driver adapted and enhanced from W5200

 Interface to the Ethernet with this flexible TCP/IP chip (use latest kernel)

Earlier work - later changed to W5200


Access SD/SDHC cards - includes virtual memory interface - treat it as 4GB

Very easy interface to FAT formatted cards and files using virtual memory


Fun both with bit-bashing, the counters, and then some WAV stuff

Extremely simple and compact word to play wave files in one cog and 96 bytes

Play any 16-bit mono WAVE file in the background with PITCH, FADE, PAUSE etc


Control individual LEDs or scroll text on a matrix

A full featured LCD driver - software contrast and brightness, big digits etc

Simulates rolling digits as in odometers, uses programmable characters

Both the 128x64 and some other types

Uses a SSD2119 chip with internal memory, you just need 3 wires


This RTC includes SRAM and EEPROM plus optional unique MAC id etc.

Fetch and store date and time/ with decimal numbers + print routines


These are pretty simple to interface to but shows you how to do it.

This chip interfaces via I2C so you can have up to 4 chips without extra I/O

Three different methods of accessing the SPI (included in EXTEND.fth)


In-circuit programming of Silabs C8051F chips from the Prop

Testing the PS/2 keyboard and what you can do too

Full turnkey project to interface SWI resistance buttons to infrared (+ IR receive)

How to read a single or multiple "touch" keys in realtime or just-in-time


Serial devices

Interfaces to common serial LCDs and devices


Full code for this 3A RMS/winding 128-step chip (it's tiny)

  • H-bridge motor control

Plus other code examples of PWM etc (included in EXTEND.fth)


Popular single I/O temperature and humidity sensor using polymer capacitor

Multi-dropped 1-Wire devices

Use the Parallax RFID card reader to create an access control system

Demonstrates how easy it is to interface to a common I2C accelerometer

Older software - may not work with the latest kernel

Useful for debugging - SEE with addresses or DECOMP source (old version)

Some ANSI escape sequences

The Forth source for the original VGA routines and demonstrations

Uses the I2C bus plus one other I/O to driver a ST7920 based graphic LCD

Forth Links

Great book, not so much programming, but about how to think...and so Forth :)

The "good book" on Forth - hardcopy is almost pure unobtainium (got one now)

Here's a link that Brian Riley suggested

These are mostly ANS or Gforth compatible but useful

Sal Sanci's Forth for the Propeller


(link to public document)

Please email me for any suggestions, comments etc  pbjtech@gmail.com