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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for February 12th, 2019

Berlin 10.1.2 Vcl.RibbonConsts removed, so now Vcl.ScreenTips compilation fails – Pascal Today

Posted by jpluimers on 2019/02/12

The Ribbon controls got removed since Delphi 10.1 Berlin, but the dependency in Vcl.ScreenTips remained, so:

After installing the official Delphi Berlin Update 2 I have faced nasty problem. One of my unit was using the Vcl.ScreenTips unit (for TScreenTipsWindow). And when you compile such a project you ge…

Source: Berlin 10.1.2 Vcl.ScreenTips compilation fail – Pascal Today

In the mean time however, it has been moved to GetIt: [WayBack] Ribbon Controls in RAD Studio 10.1 Berlin.

Note that the XE8 introduced [Archive.is] GetIt package manager is under the Tools menu, which is not covered by [Archive.is] IDE Insight – RAD Studio.

Anyway: here you can get it in Delphi 10.1 Berlin (now also in 10.2 Tokyo, where at first it was not available through GetIt):

jeroen

Posted in Delphi, Delphi 10.1 Berlin (BigBen), Delphi 10.2 Tokyo (Godzilla), Development, Software Development | Leave a Comment »

Build a Power Bank in $2: 7 Steps (with Pictures)

Posted by jpluimers on 2019/02/12

Cool: [WayBackBuild a Power Bank in $2: 7 Steps (with Pictures)

Via:

TL;DR:

  1. salvage 18650 batteries from laptop battery packs
  2. test to separate good ones from bad ones
  3. assemble together the good ones
    1. put them in a holders
    2. solder plusses to plusses and minuses to minuses
  4. add charger electronics
  5. test
  6. put acrylic plate on front/back

Stuff you need:

  • battery tester: https://www.amazon.com/gp/product/B01EV4RMX8
  • charger electronics: https://www.amazon.com/gp/product/B01N02QGLS
  • holders (clicks together in sets of 3 batteries): https://www.amazon.com/gp/product/B0722RPSF1
  • acrylic sheet: https://www.amazon.com/gp/product/B004DYW31I

–jeroen

https://www.amazon.com/gp/product/B01EV4RMX8

 

Posted in Development, Hardware Development, Hardware Interfacing | Leave a Comment »

Raspberry Pi and relays – follow up on Having one Raspberry Pi reset another Raspberry Pi through relay or transistor

Posted by jpluimers on 2019/02/12

I did some more research because of Having one Raspberry Pi reset another Raspberry Pi through relay or transistor.

  • [WayBackHow To Add a Reset Switch To Your Raspberry PiRemoving and replacing the USB power cable puts undue wear and tear on your Raspberry Pi, particularly the power port itself. What the system really needs is a reset switch, but sadly none was included.
  • Grove Relay board:
    • has two versions; the V1.2 schematic adds a XC6206P302MR voltage regulator to regulate 3V through the relay coil and an extra 47k Ohm pull-down resistor.
    • has a trigger on high supporting a voltage of 3V, so it works with the Raspberry Pi 3.3V GPIO pins.
    • is “normal open”, so suits the reset scenario (connect on trigger) well.
    • has no “normal closed” header, so if you need that, you’re out of luck
    • does not have optocouplers:
      • Be careful with high voltages on supplies that differ from the one powering your Raspberry Pi
        • It’s fine for resetting another Raspberry Pi powered from the same source
      • The relay is rated 250V ~ but I’d be careful (I’m not sure if this is mains electricity 250V RMS or 250V peak; if the latter, it would be suitable to 175V RMS (approximately 250/1.42 volt).
  • An excellent description (sans optocoupler) on how to connect a relay to power, ground, signal-input and both outputs is at [WayBack/Archive.is] gpio – How to add isolation between raspberry pi and relay board? – Raspberry Pi Stack Exchange (thanks [WayBack] ppumkin).
  • Many 5V optocoupler (or optical-isolator, see video below) based relay boards work fine with the 3.3V GPIO pins from the Raspberry Pi.
    If they don’t, then there are two basic solutions:

    1. Easiest: solder an extra resistor next to the signal input of about the same value (so the voltage drop over it halves), see for instance [WayBack] Controlling a relay board from your RPi · foosel/OctoPrint Wiki
    2. Harder: put an extra transistor in between to pump up the voltage to 5V, see one of the schematics below.

Details of the above can be found from the below links and images from those links.

There is also an Android App with a RaspberryPi distribution that allows you to operate relays:

Finally there are USB relays, shown way down in this post.

Often these are part of some home automation (domotica), IoT, or other, so these are relevant too:

Read the rest of this entry »

Posted in Development, Hardware Development, Raspberry Pi | Leave a Comment »

 
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