diy-VT100 got some design improvement.

diy-VT100 is on Crowdsupply: Signup now

I will take you through some of the important changes of revision 5. Design file can be found here

Slide switch – Power ON/OFF

Earlier there was a reset button to restart the system. Now, after rethinking on usecases, found that restart is indeed a usecase but realized that turn on/off is also important. Having a ON/OFF slide switch allow powering off without having to connection wire.

Note: Restart can also be performed via going to SETUP-A / SETUP-B and pressing 0 key on the typewriter key.

Powering via MicroUSB connector

Instead of just able to powering via communication header, user can now also use any mobile charger for powering. Also, the communication connector is directly connected to MicroUSB connector, it can now also be used to take power.

Initally proposed by Sandeep for rev4 but finaly made its way in rev5. Later Alan also showed interest in this feature. Since 2 people are showing interest in the same thing, more likely people will like the new feature.

Generic M3 standoff

Earlier used standoff were costly and only available from single vendor. Also, have to be soldered on PCB (practically: parmanent change).

Now, we have switched to generic standoff. 1. Allow multiple vendor. 2. Good quality is available at lower cost. 3. If anyone want to remove the standoff, it is atleast possible. un-stick the lcd from pcb and unscrew the standoff. 4. Height of the standoff can be changed even after shipping.

Brass, Steel & nylon hex standoff are available everywhere.

WIN-WIN situation: Lower cost, Quality can be maintained, Multiple option, Multiple vendor & More flexible.

2x +5V and 2x GND pins

2x GND Usecase: using a device as RX source and another for TX sink. If 2x GND pins are not provided, user have to make some kind of glue wiring to do the same. Also, having 2x GND help in lowering connector/wire resistance.

2x +5V Usecase: To feed power and take same power at the same time. (also symmetry with 2x GND) Also, having 2x +5V help in lowering connector/wire resistance.

SETUP button relocated.

Earlier the button was on side. Moved to top, should be easier to operate now.

MicroSD Card (SDIO) added

Future usecases: Logging of received content, resource storage. Someone pointed out in hackaday comment that they are interesting in using diy-VT100 as HMI hardware. Though the scope of the project is not HMI – but storage is definately going to make it one step further into HMI.

Conclusion

Overall component count have change but more usable product.

diy-VT100 is on Crowdsupply: Signup now

Source: https://madresistor.com/blog/diy-vt100-revision-5-changes/

We are excited to officially announce crowdfunding of diy-VT100!

diy-VT100: A hardware terminal with all the bells and whistles.

We have been working with Crowdsupply on the pre-launch page of diy-VT100.

We are at the last step of making diy-VT100 to everyones lab. This is your moment, signup now on the pre-launch page and get notified when the crowdfunding is active.

diy-VT100 will have atleast Rev. 4 features.

• 5 Inch LCD (800×480 Pixels)
• Digital To Analog converter based sound (feep! feep!)
• USB and PS/2 Keyboard support
• Preference saved in EEPROM
• Dedicated SETUP button

Full details on the pre-launch page.

At backend, we have been communicating with suppliers and manufacturers to confirm all parts and plans.

Source: https://madresistor.com/blog/diy-vt100-crowdfunding/

Like promised, here is the complete firmware & hardware design.

https://gitlab.com/madresistor/diy-vt100-hardware

https://gitlab.com/madresistor/diy-vt100-firmware

Licence: GPLv3 or later (Free / Libre / Open source)

In the git history you can find the rev2 firmware and hardware design too.

We are retro enthusiast and loved to know how old technology worked.

Since we live in a geographical location where technology was adopted late

(Like most economically developing countries, a big part of the computer & computing was skipped/missed.)

I was always curious about computing, computers, its history and how technology came to its present day.

I read alot and came to know that terminals were used with CPU and were bought [mostly] seperately.

VT100 is one such big name in computer terminal history.

I wanted to implement a terminal that was designed with todays technology but take its user to the terminal era. They should feel how it worked and still in use.

While working with MSP430, i realized that serial protocol is still [widely] in use for logging, communication and debugging in microcontrollers.

One could attach this to SBC (Single Board Computers) & Microcontrollers and get a CLI just like old times!

With newer version, i have made diy-VT100 feel more-and-more like original VT100.

• Now a recorded audio of VT100 BELL is generated via DAC. (Original like sound!)
• Keyboard LED (including Host controlled).
• Full 80x24 character support
• SETUP mode act just like original VT100 setup mode
• USB & PS/2 Keyboard support - these are used today
• Portable and small

We not limiting diy-VT100 to VT100 only. (VT100 is only a starting point.)

Older, Newer, different-other-than-VT100-family can be implemented with the same hardware.

We hope to preserve the computer hardware terminal history and at the same time design tools that are useful for hackers and makers.

If you have a working VT100 (or VT102) and could donate to us in India, that would be very helpful!

~~~ Kuldeep & Sandeep

I will take through the project licence.

Prototype Rev1

• Schematics - Yes (Available under GPLv3 or later)
• PCB - Never designed (Only on Zero PCB)
• Firmware - Yes (Available under GPLv3 or later)

Firmware: https://github.com/kuldeepdhaka/diy-vt100

Schematics: https://github.com/kuldeepdhaka/diy-vt100/tree/master/doc/msp430g2553/schematic

Prototype Rev2

• Schematics - Yes (see note1)
• PCB - Yes (see note1)
• Firmware - Yes (ported rev1 firmware to STM32F105, i.e. Mostly backend re-write | see note2)

note1: The design had issues [accidentally used non 5V tolterant pins for 5V I/O].

So, Didnt make the design public because it could be a problem for potential users.

Also, PCB making cost money and people were requesting bigger lcd (which was not possible with the current uC], so a re-design of this version was never done.

note2: USB Host stack already merged in UniCore-MX (under LGPL 3.0 or later).

Example code is also available in UniCore-MX example repo.

Firmware use the USB Host stack example code as it is (with tini-wini target specific modification].

In rev2, 90% of the time on firmware was used for writing USB Host stack from scratch.

Prototype Rev3

• Schematics - Yes (see note3)
• PCB - Yes (see note3)
• Firmware - Partial (see note3)

note3: the uC used (STM32F469V) could not be sourced [without long waiting] and was a bad idea to use it. Realized it is very hard to find and not a good sign for future.

So, this revision was dropped all together.

Prototype Rev4

• Schematics - Yes
• PCB - Yes
• Firmware - Yes (Mostly a rewrite of rev2 firmware - substancial improvement to code)

We are working on this prototype.

Recently improved by-pass filter and bulk capacitor in design.

This is the version that we expect to make to users (with minor improvements ) [lets see].

Development tools

Our project use only Free/Libre/Open Source tools for all development (all revisions).

arm-none-eabi-gcc, Makefile, KiCAD, OpenOCD etc.. has been used to develop the project.

Library

Revision 2, Revision 3 & Revision 4 uses UniCore-MX for hardware abstraction.

https://github.com/insane-adding-machines/unicore-mx

UniCore-MX is under LGPL 3.0 or later.

Conclusion

All library and rev1 code is already public.

Only the F105, F469, F767 specific firmware modification and pcb design is not publically available.

Since F105 (rev2) had design issues [re-design required], continuing F469 (rev3) is not a good idea.

This Only left us F767 (rev4) - which is eventually be made public under GPLv3+ like all our projects.

Minor issue in releasing: Few design files (1x Footprint, 1x 3D) are still not specifically released under GPLv3+ compatible licence.

Waiting-for / trying-to-contact author (s).

In this demo, diy-VT100 is used to see Serial log generated by the Arduino sketch.

- Bell (Speaker - 800Hz)
- 7 LED (ONLINE, LOCAL, KBD LOCKED, L1, L2, L3, L4 )
- USB and PS/2 Keyboard
- UART 3.3V (5V tolerant pins & Multiple speeds)
- LCD (32x20 characters)
- Accept VT100 commands (most of them - at the moment)
- EEPROM to store configuration
- Uses STM32F105 (ARM uC M3)

The fully assembled diy-VT100 rev4 with a bigger lcd and stm32f7

a DIY cardboard stand for our diy-VT100 :)

diy-VT100(rev-2) debugging diy-VT100(rev-4)

Freshly arrived F7 microcontrollers from Digikey