1.8" TFT capacitive single touch (whole screen button) - Page 1
Forum section: electronics / projects

author: jakej
author_rank: Newbie
timestamp: October 28, 2016, 05:48:12 pm
content: I was thinking about applications for these fairly inexpensive 1.8" TFT modules:https://www.aliexpress.com/item/1-8-Serial-TFT-LCD-Color-Display-Module-With-SPI-Interface-5-IO-Ports-128X160/32435498225.html?spm=2114.01010208.0.0.Z4fjlYIf I wanted the surface of the lcd to be a capacitive touch button (the entire surface, not multi-touch), how would I approach that in an inexpensive manner?

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 28, 2016, 07:06:47 pm
content: You can buy lcd colour touch screens starting from $3, so wouldn't that be the cheapest option?

author: daveshah
author_rank: Unknown
timestamp: October 28, 2016, 07:12:49 pm
content: This would need to be tested, but perhaps a layer of ITO coated glass (such ashttps://www.adafruit.com/product/1310) connected to a microcontroller capacitive touch peripheral or capacitive touch button ASIC might work?

author: jakej
author_rank: Newbie
timestamp: October 28, 2016, 07:28:04 pm
content: Both great ideas. There are 2.4 inch lcds for quite cheap on aliexpress. I think that they are resistive touch, though:https://www.aliexpress.com/item/2-4-inch-16bit-262K-TFT-LCD-Screen-with-Touch-Panel-LT1763-Drive-IC-240-320/1902116021.html?spm=2114.01010208.3.10.o8A85U&ws_ab_test=searchweb0_0,searchweb201602_2,searchweb201603_1&btsid=336f0a00-3af7-45ae-8d56-11811d34f8b8https://www.aliexpress.com/item/Free-Shipping-1pcs-2-4-inch-TFT-touch-LCD-Screen-Module-For-Arduino-UNO-R3/2034511569.html?spm=2114.01010208.3.1.qLmOd2&ws_ab_test=searchweb0_0,searchweb201602_2,searchweb201603_1&btsid=450da76d-7df2-49ae-adc6-f9e980159ae4I'll have to get my hands on some ITO coated glass and try that out. That might work out well since I was thinking about making a row of TFT buttons and a single pane of glass could cover them all.Thanks for your thoughts!

author: ChristopherN
author_rank: Unknown
timestamp: October 29, 2016, 05:11:29 pm
content: ITO covered glass can be quite expensive and might be hard to contact.You could install a physical button beneath each display, this would give the user feedback and can be done cheaply if you are using a foam pad beneath each display.

author: amyk
author_rank: Super Contributor
timestamp: October 29, 2016, 11:00:10 pm
content: Quote from: ChristopherN on October 29, 2016, 05:11:29 pmI was thinking of this too. Simplest solution that works. Just make sure to put a layer of glass or other stiff material over the screen, if they weren't originally designed for touching the top surface won't be strengthened to allow it.

author: Lukas
author_rank: Frequent Contributor
timestamp: October 29, 2016, 11:15:21 pm
content: Since the display you want to use doesn't seem to contain a lot of metal, you may try placing the capacitive button behind the display.

author: ebclr
author_rank: Super Contributor
timestamp: October 30, 2016, 12:40:30 am
content: Will be smart buy this board and take the displayhttp://www.mouser.com/ProductDetail/STMicroelectronics/STM32F412G-DISCO/?qs=sGAEpiMZZMuqBwn8WqcFUjZ%252bN9y5YW6jVeNMCEITWK15sd5dkR35RQ%3d%3dor even this cheap watchhttps://www.aliexpress.com/item/U8-U80-Bluetooth-Smart-Watch-Fashion-Casual-Bluetooth-Watch-Digital-Sport-Wrist-LED-Watch-For-iOS/32751238921.html?spm=2114.01010208.3.61.vc86vi&ws_ab_test=searchweb0_0,searchweb201602_2,searchweb201603_1&btsid=0f5d985e-3c4c-4499-b85d-54150e24c7db