Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A64 => Topic started by: HarrisonCreates on November 12, 2019, 03:24:42 AM

Title: How to Power LCD Touchscreens?
Post by: HarrisonCreates on November 12, 2019, 03:24:42 AM
Hello All,

I am attempting to get my Olimex A-64-1Ge4GW to power and display on an LCD cable. To present, I have done the following:

1.) Stopped u-boot and manually configured the board to search for LCDs.
2.) I ran saveenv, and reset
3.) When I plug in the board, the LCD panel flashes white for a second but nothing else displays. The board boots perfectly fine when connected to HDMI.
4.) I am running the board on WiFi, so there's shouldn't be any Ethernet/LCD mumbo jumbo going on.

I even tried powering the touchscreen with a separate 5V barrel jack while the A64 was on and still nothing. Any tips?

Thank you!!
Title: Re: How to Power LCD Touchscreens?
Post by: LubOlimex on November 12, 2019, 09:23:30 AM
Did you close the jumper PHYRST1?

What is the display exactly?

Can you shows us a picture of the connection between the board and the LCD? Maybe upload it to another web-site and give us the link.
Title: Re: How to Power LCD Touchscreens?
Post by: HarrisonCreates on November 12, 2019, 08:01:24 PM
I soldered PYSRST1 shut and it seems to work now, I was trying to use the little plastic piece the board came with as a bridge but realized it wasn't making contact with the pins. I am doing light prototyping, so a solder bridge works just fine!

I am now having a different issue. The board begins to boot but somethings gives out and the board shuts down. From reading what other people have posted, this is due to a bad power supply. I am using a Samsung Fast Charger block, which from what I read is capable of producing around 2A at 5V. Is this not enough to power the board and touchscreen?

One additional mention; I plan to run this system on a 3.7V Lithium battery; the one I have is rated for 3000mAH, so would this product enough current to run both the board and screen?
Title: Re: How to Power LCD Touchscreens?
Post by: LubOlimex on November 13, 2019, 10:15:38 AM
Where do you apply the power from the charger? To the micro USB connector or to the barrel power jack?

The Li-Po is alright it would keep the setup operational for quite some time.
Title: Re: How to Power LCD Touchscreens?
Post by: HarrisonCreates on November 13, 2019, 08:38:56 PM
Hello LubOlimex,

It's a relief to hear about the battery! Thank you for letting me know, I'll find a battery with the correct wire polarity!

Regarding the charger, I am connecting it to the barrel jack. I soldered my own USB cable to the barrel jack wires, so maybe the wire gauge is getting in the way of delivering optimal current. Either way, maybe I should try with the battery, since the board is optimized to convert 3.7V to 5V and pull enough current.