Wiring up a 1602 LCD to a shield

I’m trying to connect a 1602 LCD to my project via a ‘utility’ type shield – it has terminal blocks and a pattern of plated holes for any components.

After looking at alternatives I settled on using multicolored DuPont connector wires (the ‘buy a bunch cheap’ brand from Banggood IIRC), one end soldered to the LCD and the other tinned and screw clamped to the shield. I did this partly because I have a bunch on hand and partly because I can use several different colors as it will get more crowded as the other parts of the project are added.

However, this is getting ugly as the wires will tolerate almost no flexing at the LCD connection – I no sooner fix one than another breaks off. I’m not proud of the soldering but I don’t think that explains the fragility of these wires.

In the pictures with the black enclosure (with Arduino and H-bridge installed) I’m holding the display approximately where it will be when the cover is on. As can be seen things will be snug.

My question: Will better quality wire solve this or, do I need to find another way to make these connections?

broken wire.png

broken wire.png

An additional picture

Those jumpers are super cheap, super fine wire with only a few strands with no mechanical strength made worse by soldering. The solder will wick up to the insulation and with no strength, any flex will break the conductors. They are only suitable from crimp connections (as shipped) since the very thick insulation provides the only strength they have. They’re okay if you use double female pinned jumpers and solder header pins on either end. That has worked well for my 1602’s although I always use I2C backpacks so they only require 4 wires.

If you really want to solder everything, buy some decent (Alpha, Belden, insert brand name here) 24 or 26 gauge stranded wire. Order from DigiKey or Mouser, avoid cheap Chinese wire like the plague as you get what you pay for, some times it’s not even copper.

I was assembling something with some of those "Dupont" wires, cutting them to use the Dupont female on one end and solder the other to my ESP8266 USB adapter.

The wire in them was not tinned and proved quite impossible to solder to. Something in the insulation instantly contaminated the copper surface.

You buy cheap wires from china you get CCA, not copper. CCA is much less ductile than copper and
you should always avoid it. CCA = copper-coated aluminium. You need to get some decent hookup wire.

MarkT:
CCA = copper-coated aluminium. You need to get some decent hookup wire.

CCA? No wonder! :astonished:

WattsThat:
If you really want to solder everything, buy some decent (Alpha, Belden, insert brand name here) 24 or 26 gauge stranded wire. Order from DigiKey or Mouser, avoid cheap Chinese wire like the plague as you get what you pay for, some times it’s not even copper.

Roger that! I just got several things from Jameco, if I'd waited I could've added that to the order. :frowning:

Paul__B:
I was assembling something with some of those "Dupont" wires, cutting them to use the Dupont female on one end and solder the other to my ESP8266 USB adapter.

The wire in them was not tinned and proved quite impossible to solder to. Something in the insulation instantly contaminated the copper surface.

I was able to tin these, basically had to to avoid whiskers (and still got some) but, yes, when the insulation pulled back from heating the untinned wire had this weird purplish discoloration.

MarkT:
You buy cheap wires from china you get CCA, not copper.

That explains a lot. I suspected something along those lines.

Thanks for the replies! Now to go shopping. Sure would be nice to have RS or Fry's around to drive to.

I've located a local hobby shop as a source of suitable wire. The brands they named - Brawa and NTE - are not familiar to me. Can anyone make a statement as to the quality of these brands?

NTE is a repackager/rebrander that sells to the electronics repair trade. They main line is generic semiconductors with a substitution list. Basically, overpriced, relabeled stuff for the tv repair trades of which I expect there is little demand these days. Never heard of Brawa. The last store I knew of that carried NTE was Bainsville Electronics in NW suburban Baltimore. They closed about two years ago.

You’ll probably pay no more buying brand name products from DigiKey and Mouser.

WattsThat:
Never heard of Brawa.

Me neither. More searching reveals that Brawa is a well known brand in the model RR trade. I ordered some 25.5ga. from
Cherry Creek Hobbies.

I'd heard of NTE semiconductors but I did not know they handled wire also.