Replace Enviro+ Screen?

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#1

Is it possible to replace the screen on the Enviro+?

I unwittingly used a GPIO ribbon cable that wasn’t intended to be an extension for “hats” and as a result, I believe the over voltage damaged the screen. All the other sensors still appear to function, but the screen was sort of the thing I was really looking forward to.

It previously worked fine when plugged directly into the Raspberry Pi, and it worked briefly once I had built my own wiring harness, but I think the damage was already done at that point.

#2

Maybe? If you had cracked it or only damaged the screen part, you could likely buy one of these and carefully do a swap of the screen part after undoing the ribbon cable.
0.96" SPI Colour LCD (160x80) Breakout – Pimoroni
It’s still a bit risky as you could crack it getting it off of the breakout.
Honestly though, best guess is its the part that drives the screen that’s fried, the bit on the enviro+.
You could use the above linked to breakout in place of the enviro screen. Just wire it up so it uses the other chip select and enter that in the screen config part of your python file.

disp = ST7735.ST7735(
    port=0,
    cs=0, # instead of cs=1
    dc=9,
    backlight=12, # << may have to also change this?
    rotation=90,
    spi_speed_hz=10000000
)
#3

If the screen is just held in place with double sided sticky tape or sticky pad, you can get it off by pulling dental floss or fishing line behind the display. You just do a slow back and forth motion and saw the pad in half. Once the display is off you can peal off what’s left of the sticky stuff with your finger nail etc.

#4

One thing I would definitely do is check the 3.3v pin on the Pi’s GPIO. If it reads 0V that Pi is dead. The 3.3v regulator has been fried if it shows 0V on pin 1.

#5

I am getting 3.3v of the PI, although and please correct me if I’m wrong, based on the pinout I didn’t appear the Enviro+ needed that, pulling its power from the 5V rail instead?

As luck would have it, I actually impulsively purchased one of those screens you suggested and have it on hand. I suppose I could redo a couple things to make use of that now. I’d probably have more luck that way than trying to carefully peel it away and reapply it to the Enviro+.

#6

Ok, pi is likely fine. I’d hook the display up as is to that Pi just to make sure SPI is working OK. I use the scrolling-text example as a test file.
I’m thinking it’s more likely its the display driver bit that fried. The electronics on the enviro that drive the display, not the display itself.

#7

Hmmm… I wonder, if it would be at all possible just to replace that? I’d bet it’s an IC of some sort?

I could also just get another. Then use this one for an air quality station where a display isn’t needed. I was thinking of making another outdoor one for the front of the house.

#8

SMT stuff is really hard to work on with basic home soldering tools etc.

#9

Screen driver chips are usually built-in to the screen, so it’d be a case of buying a new screen and replacing it. You’d need to get one with the exact same driver chip (ST7735) and flat-cable format, maybe something like this?

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#10

Ok, maybe I got that a bit wrong? I have several of the Breakout Garden versions of that screen. I just assumed the driver chip was on the backside of the circuit board. Looking at the product pictures, it appears Shoe may be right?
I’d need a magnifying glass or microscope to read any chip numbers though.
You may be able to undo the ribbon cables on the breakout and Enviro+, and hook the breakout garden screen to the Enviro+ to test it. If it works then wory about getting it off without breaking it. Just be warned, doing this may kill your working screen, if something on the Enviro got fried, that then fried the first screen.

#11

Thank you Shoe; for that price I could probably get a few and try at least. If it doesn’t work, I end up where I’m at now anyway.

#12

Looking at he numbers on the ribbon and the units being offered, I think this might be a good replacement. I’m going to give it a shot and see what happens.

#13

Well, I think I’ve now confirmed the screen driver on the Enviro+ is toast. I installed the new screen and it did the same as the last. I even ran a couple of the example scripts that were provided with the Enviro+, ones I knew displayed well previously, and nothing happened.

There was a brief glimmer hope when the screen briefly flickered, but I think that’s all we’re getting. Sadly, this probably means the old screen was just fine. However, I’m pretty sure the ones that @Shoe suggested are the equivalent replacement.

So I’m guess now I either need to get a replacement for the SMD chip on the Pimoroni or… buy another. I’m bummed, but I’m not sure I’m $60+ USD bummed considering everything else works.

#14

My background is in electronics so I’m usually very careful just by nature. Got careless one day and plugged a Pi Zero in one row off. The Pi was powered via the GPIO so +5V went in the 3.3V pin. Magic Blue smoke came out. The PI won’t work without it so I had to replace the Pi Zero. Luckily nothing else got damaged, I had a pHat Beat in the mix.
So far knock on wood (taps forehead with fist =) ) that’s all I have fried.
Anyway, to make a long story short, it happens, we are human, we make mistakes.
Even to those of us (me) that think we know what we are doing. lol.

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#15

That’s a real shame. Without a schematic it’s hard to know what may have been damaged, and at any rate the likely culprits are teeny things which are going to be difficult to properly replace. At least you should still be able to add other LCD breakouts if you really need a screen.

Actually, have you confirmed that the SPI pins on your Pi are still functioning? It could be that the pins were damaged. Alternatively, would you have a second Pi to test the HAT with?

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#16

Well, I’m going to do my Nth check on the wiring and see if I’ve somehow messed up the connection that the pin-out said was handling the display. For good measure, I’ll check everything else too.

I do have another Pi Zero from another gadget that I upgraded, so I will try that as well. It’s easily replaced in the system.

And if I haven’t already said it, thank you both for your input, guidance, and insights.

#17

I like to make up a lot of crib notes on stuff like this. I have been doing a bunch of stuff with SPI0 and SPI1 lately
The pins in question are as follows.
The Enviro I believe uses SPI0 CE1.

SPI0
GPIO 7, Pin 26, CE1
GPIO 8, Pin 24, CE0
GPIO 9, Pin 21, MISO
GPIO 10, Pin 19, MOSI
GPIO 11, Pin 23, SCLK

SCLK - Serial ClocK
CE - Chip Enable (often called Chip Select)
MOSI - Master Out Slave In
MISO - Master In Slave Out
MOMI - Master Out Master In

#18

@alphanumeric , I think I’m misinterpreting how to read the Pinouts on pinouts.xyz then.

I thought the pins that were highlighted were all that were needed, but maybe I really should be connecting all those that have text in parentheses or should I just connect them all?

It would not surprise me one wit if all of this trouble was caused by me not understanding this business.

#19

The Enviro+ only uses SPI0, and even then only GPIO 7,9,10,11, so those are the only ones you need to use.

Are you not attaching the board directly to the Pi? Are you using jumper cables? If so that could quite possibly be the culprit. A clear photo of the wiring (clear enough to let us see which pins are connected) would show if this is the case, or else try the board attached directly to the Pi to eleminate that.

#20

I’m adding a few more wires and I’m going to give this a shot. I think I might have missed some. If this fails, you bet I’ll be sending a picture of the wiring up. Which is probably smarter than flipping my entire desk and going watch TV.

I kid, I actually enjoy this even if I’m the source of a solid 95% of my issues.