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diy-VT100 Revision 5 Changes

A project log for diy-VT100 - A Miniature hardware terminal

Miniature VT100 with all the bells and whistles

Kuldeep Singh DhakaKuldeep Singh Dhaka 08/24/2017 at 02:080 Comments

diy-VT100 got some design improvement.

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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.

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


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