Diode orientation for Color 320x240 TFT Touchscreen Purple Board?

VashJuan

VashJuan

Member
I'm assembling the purple test board to hook up a new Teensy 4.1, Audio Board, and the recommended 3.2 TFT SPI display.

I'm uncertain which way the diode B130 goes. The diode has a bar on the cathode (-) side but I don't find this symbol
1700592471919.png
in my web search for standard ways to mark diodes on a breadboard. I'm guessing the extra space behind the B13 part of the label is sort of like a negative sign, albeit sideways. So then I'd put - on the left, and + on the right in this orientation. Right?!
1700592378171.png


The purple boards I just received from OSH Park (https://oshpark.com/shared_projects/TG395I75) do NOT have room for the two 10K resistors, nor room for all 14 pins of the display, the boards only have room for 9 pins.

The 0.1µF capacitor is not marked on the PCB either, but I presume that's what the pads on the back are for. But they are pads, not a through whole connection which is what the specified part (https://www.digikey.com/en/products...draloric-bc-components/K104K15X7RF5TL2/286538) is. Hmmm...

Did I order the right purple boards?! (I followed the link under the photo at https://www.pjrc.com/store/display_ili9341_touch.html.

THANKS!
 
The diode is a reverse voltage protection diode, so it would be placed so that the cathode with the line is on the right towards the regulator.

I don't know anything about this board, but it doesn't sound like you got the right board. The last 5 pins on the display are used for touch, so perhaps it doesn't support touch if it only has 9 pins but the display itself may work?
 
The side with the stripe is cathode. When you look at a real B130 diode, you'll see it has that stripe printed on top.

1700598368221.png


Edit: the diode in this photo is actually a B120 - as apparently I don't have any B130's handy in my Schottky diode bin.
 
Thanks for the reply too Paul, and for the original work on the purple boards!

Are these boards still appropriate for connecting the Teensy 4.1 to that display? See my comments under the schematic in my original post.

(I guess I can try breadboard connections before soldering components into the boards...)
 
Just to make sure I answered your question, yes, the PCB shown definitely does work with Teensy 4.1 and the ILI9341 display.

But if you have a different PCB than shown, then the answer is maybe. I hope you can understand how impossible it is to answer definitively when I can't know which PCB you actually received.
 
Oh no issues Paul! I'm just appreciate for all you do. Here are the pictures of what I got. Definitely not the same as displayed on their page. Hmm.
20231121_124907.jpg
20231121_124900.jpg


The OSH Order just describes them as "ILI9431 Display (320x240) to Teensy 3.1 copy"
oh oh, https://oshpark.com/orders/yTU7Rsk1 shows what I got for $13.30:

Not sure how I ordered those when I wanted for $14.40...

OSH Park ~

oshpark.com oshpark.com
The link at https://www.pjrc.com/store/display_ili9341_touch.html goes to the right place...

I tried finding any link to the wrong/old project at OSHPark, but can't find one from the PJRC site. Maybe some old YouTube notes or something.


Argg. I'll order the right boards & sorry for the hassle!
 
At least 4 versions of this board were made over the last ~10 years. Maybe you ordered these years ago?

If you ordered recently and the order info shows you definitely did order the current version, then you should contact OSH Park about getting the wrong board. If they really did somehow send you the wrong board, I'm sure they'll be willing to redo it. Lean and the OSH Park folks are good people.
 
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