Project Update
First a few words about the current status of the ChipStick project.
This week, the first of the prototype ChipSticks have been sent out to the "Early Adopters" - those with the skills and experience to port Forth onto the device - and thereby "hit the ground - running".
I have also spent some time working on the method for bootloading the device using the CH340G USB comm port and a PC BSL Scripter tool. This is now working on a modified prototype board, and these mods will either be handled with a board revision or some change to the available scripting tools.
I/O!
When I first devised SIMPL - as an extension to Txtzyme, I believed it to be a great means to improve the quality of interaction between the User and the embedded device, especially when coupled with some interactive hardware such as LED arrays and switches.
Within a few days of the first version of SIMPL, I was connecting it up to LED arrays, and devising a user word "n" which would display the number in binary on a LED array.
Digital outputs are connected to Port 2 and numbered 0 to 7, and each may be connected to a LED via a suitable (270R) resistor. With this it is possible to turn on individual LEDs, or to have them display an 8 bit binary number.
In it's basic configuration, an array of up to 8 LEDs can be supported and three push switches.
With the addition of some extra hardware, an 8x8 LED array or a 32 key keyboard can be used.
Shift Registers
Shift Registers are the key to economic expansion of the hardware. They are ideally suited to the SPI bus environment and can handle reasonably high speed transfers or data both out of and into the mcu.
The 74HC595 is a serial to parallel converter, costing around $0.10 in volume and ideal for driving LED arrays and keyboard scan lines. The 74HC165 provides the complementary function of parallel to series conversion - and is great for scanning key matrices and arrays of digital inputs.
During this week, I had a little success getting an array of 7 LEDs to mimic the stack operations and one upcoming project will be to use a pair of external 74HC595 shift registers to extend these LED arrays to extend the stack viewer to the full 16 bit.
I have already made a start on this by digging out the hardware used on my "shift register" breadboard - first used back in 2014 for my "A Little Bit Shifty" blog post, where I explored the use of shift registers for input, output and driving stepper motors. This board allows an additional 16 output bits to drive LEDs and 16 input bits from switches. This makes it possible to use ChipStick to recreate 60's style Retro Computers - similar to the Kenbakuino.
It's great to see the effect on the LEDs following stack arithmetic and logic operations - a wonderful, visual and interactive way to learn binary arithmetic and boolean logic.
Memorable Events
Last weekend, I had the opportunity to catch up with writing some new firmware functions to get the 128K memory working, so now most of the pieces of the "Forth Computer" are starting to fall into place.
The remaining parts still to work on are the code that will interface to PS2 kepboard and mouse, and of course tying in the system hardware with the FT812 embedded video engine hardware.
This has just become the subject of a recent post.
First a few words about the current status of the ChipStick project.
This week, the first of the prototype ChipSticks have been sent out to the "Early Adopters" - those with the skills and experience to port Forth onto the device - and thereby "hit the ground - running".
I have also spent some time working on the method for bootloading the device using the CH340G USB comm port and a PC BSL Scripter tool. This is now working on a modified prototype board, and these mods will either be handled with a board revision or some change to the available scripting tools.
I/O!
When I first devised SIMPL - as an extension to Txtzyme, I believed it to be a great means to improve the quality of interaction between the User and the embedded device, especially when coupled with some interactive hardware such as LED arrays and switches.
Within a few days of the first version of SIMPL, I was connecting it up to LED arrays, and devising a user word "n" which would display the number in binary on a LED array.
Learning by Fun!
ChipStick is all about having fun learning about electronics and computing - so that's why it comes with some preprogrammed words to allow LED displays and musical tone generation to be explored. ChipStick's hardware has been made as versatile as possible, with the aim of future expansion.Digital outputs are connected to Port 2 and numbered 0 to 7, and each may be connected to a LED via a suitable (270R) resistor. With this it is possible to turn on individual LEDs, or to have them display an 8 bit binary number.
In it's basic configuration, an array of up to 8 LEDs can be supported and three push switches.
With the addition of some extra hardware, an 8x8 LED array or a 32 key keyboard can be used.
Shift Registers
Shift Registers are the key to economic expansion of the hardware. They are ideally suited to the SPI bus environment and can handle reasonably high speed transfers or data both out of and into the mcu.
The 74HC595 is a serial to parallel converter, costing around $0.10 in volume and ideal for driving LED arrays and keyboard scan lines. The 74HC165 provides the complementary function of parallel to series conversion - and is great for scanning key matrices and arrays of digital inputs.
During this week, I had a little success getting an array of 7 LEDs to mimic the stack operations and one upcoming project will be to use a pair of external 74HC595 shift registers to extend these LED arrays to extend the stack viewer to the full 16 bit.
I have already made a start on this by digging out the hardware used on my "shift register" breadboard - first used back in 2014 for my "A Little Bit Shifty" blog post, where I explored the use of shift registers for input, output and driving stepper motors. This board allows an additional 16 output bits to drive LEDs and 16 input bits from switches. This makes it possible to use ChipStick to recreate 60's style Retro Computers - similar to the Kenbakuino.
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| ChipStick gains additional 16 Inputs and 16 Outputs using Shift Registers |
It's great to see the effect on the LEDs following stack arithmetic and logic operations - a wonderful, visual and interactive way to learn binary arithmetic and boolean logic.
Memorable Events
Last weekend, I had the opportunity to catch up with writing some new firmware functions to get the 128K memory working, so now most of the pieces of the "Forth Computer" are starting to fall into place.
The remaining parts still to work on are the code that will interface to PS2 kepboard and mouse, and of course tying in the system hardware with the FT812 embedded video engine hardware.
This has just become the subject of a recent post.