Waveshare 1.69 Touch Issue, help

[extremesecrecy]

Hi, I was trying to upgrade from my zero without screen to the screen version, but the screen fries when I connect it. I used a converter from 9v to 5v and the reading is fine.
Gray Cable is the V+
Purple is the Ground V-
Blue Cable is the 3v
Black Cable at the end is the GP IO18.

Is this right?

[Builty]

Hi.
I guess this is the 1.69" Waveshare board?
Those cable colours are correct.

I would suggest running some basic tests.

• remove the wire connector, and just plug in a USB-C cable for power (no Tonex yet.) Does the display work OK then? If it doesn't the board might be faulty. But first try to flash it again to make sure, and make sure you use the right firmware file.
• if the USB-C power works, then unplug it and just connect the 5v and ground (gray/purple wires.) Nothing else. Check if that works.
• after this, try with the Tonex connected to USB-C
• finally try with Midi connected

This should help us track down what the issue is.

[extremesecrecy]

It is 1.69" Waveshare board (touch). I will try this as soon as the new screen comes in. Thanks!

[extremesecrecy]

Here is the setup. *Before attaching the screen.

[extremesecrecy]

When I measure voltage from the Gray+ to any of the other cables, it is always about 5v. Is the 1.44 amp ok?

[Builty]

How are you measuring the 1.44 Amps? The PCB will not draw anywhere near as much current as this. If this is what the PCB current draw is, then its likely you have a short circuit.

Is your 9v power support negative on the centre pin or positive? You have a red wire on the centre, but the standard for guitar power supplies is centre negative. make sure its not reverse polarity. The 5v on multimeter probably means that the polarity is OK though.

[extremesecrecy]

The 1.44 is directly out of the converter, I have not yet connected the actual waveshare to this. I don't want to connect one if this is the wrong amps and it will fry it. The barrel jack I bought had the red wire on the center, but like you mentioned, the guitar pedal power supplies are center negative, so it looks reversed.

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On Sat, Mar 1, 2025 at 1:15 AM Builty ***@***.***> wrote: How are you measuring the 1.44 Amps? The PCB will not draw anywhere near as much current as this. If this is what the PCB current draw is, then its likely you have a short circuit. Is your 9v power support negative on the centre pin or positive? You have a red wire on the centre, but the standard for guitar power supplies is centre negative. make sure its not reverse polarity. The 5v on multimeter probably means that the polarity is OK though. — Reply to this email directly, view it on GitHub <#82 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACTTSQJAES6EUVV2H7VUMED2SF3CLAVCNFSM6AAAAABX37R52CVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTEMZVHEZDKNA> . You are receiving this because you authored the thread.Message ID: ***@***.*** com>

-- *Gabriel Hernandez* *4648 Merrick Court, Oceanside CA* Cell: 760-271-3708

[marcuslupinus]

I would suggest you refresh your electricity 101 course... There are a lot of resources on the web - it will help you all your life long.

You can measure voltage in a circuit even if it is an open circuit - like what you are doing without the waveshare plugged in - meaning no current has to be flowing. Voltage is 'available' at the output of the PSU. But current is not measured the same way and does not work the same way - current is 'flowing' through the circuit, when there is no circuit, there is no current flowing so you cannot measure any current. If you have a power supply that can supply, for example, 10 amps at 5 volts, it means that It will provide 5 volts and it will be able to provide from 0 amp to a max of 10 amps to the circuit at that voltage. The amount of amp flowing depends on how much current the circuit 'needs' (it's resistance if you want). If you hook up a circuit that only required 0.5 amp at 5volt, it will 'draw' 0.5 amp from the power supply, there is no way you can fry the circuit. The opposite is bad: if you connect a circuit that consume 20 amps at 5v to the same power supply, you will fry the power supply, not the circuit.
Also, you don't use your multimeter the same way for measuring voltage and current. For current, your multimeter must be in 'series' with the power supply and the circuit (psu+ -> meter+, meter- -> circuit+, circuit-gnd -> psu-gnd).

[extremesecrecy]

Thanks for the advice, I will refresh. I guess, what I was expecting when I measured it was 0 amps. That is why I posted. 3 screens burned already and everything read like I just showed. I was trying to make three of these pedals. One for myself and to give 2 to my friends. But, all the screens stopped working the same way. (I had preloaded tonex controller through usb.) https://www.amazon.com/gp/product/B0D818GS29?ie=UTF8&th=1 From Amazon: - The maximum output current can reach 1.8A, when the output current is 1.5A, the output voltage is 4.6V The 1.4A read is as expected on the device. But, I just wanted to double check with you guys if that was ok for the Waveshare 1.69 touch. I was expecting that if it was wrong, the converter was going to burn, not the screen.

…

On Sat, Mar 1, 2025 at 8:29 AM Marc Lupien ***@***.***> wrote: I would suggest you refresh your electricity 101 course... There are a lot of resources on the web - it will help you all your life long. You can measure voltage in a circuit even if it is an open circuit - like what you are doing without the waveshare plugged in - meaning no current has to be flowing. Voltage is 'available' at the output of the PSU. But current is not measured the same way and does not work the same way - current is 'flowing' through the circuit, when there is no circuit, there is no current flowing so you cannot measure any current. If you have a power supply that can supply, for example, 10 amps at 5 volts, it means that It will provide 5 volts and it will be able to provide from 0 amp to a max of 10 amps to the circuit at that voltage. The amount of amp flowing depends on how much current the circuit 'needs' (it's resistance if you want). If you hook up a circuit that only required 0.5 amp at 5volt, it will 'draw' 0.5 amp from the power supply, there is no way you can fry the circuit. The opposite is bad: if you connect a circuit that consume 20 amps at 5v to the same power supply, you will fry the power supply, not the circuit. Also, you don't use your multimeter the same way for measuring voltage and current. For current, your multimeter must be in 'series' with the power supply and the circuit (psu+ -> meter+, meter- -> circuit+, circuit-gnd -> psu-gnd). — Reply to this email directly, view it on GitHub <#82 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACTTSQIYFFZIRFJD5TFJ3JL2SHOAPAVCNFSM6AAAAABX37R52CVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTEMZWGEYTSNQ> . You are receiving this because you authored the thread.Message ID: ***@***.*** com>

-- *Gabriel Hernandez* *4648 Merrick Court, Oceanside CA* Cell: 760-271-3708

[Builty]

the screen would only generally burn up if the voltage was higher than 5 volts, or possibly from the wrong polarity. Or, connecting the power supply to the wrong pins on the board.
It's hard to see the issues from the photos and description though, but I think its something in this area.

[extremesecrecy]

The new screen worked with the pedal I put together. But, when I connect it to the USB, it shorts and the screen turns black. So far it has not burned out, but I am unable to connect to the pedal. The screen that I got was the touch v2 for waveshare 1.69. I

[Builty]

So when you connect the Tonex pedal to the Waveshare USB port, the screen goes black? That would suggest the power supply is not enough current, however from the specifications you have shown it should be plenty enough.

Its really difficult to diagnose this kind of issue from across the world. It could be something with the regulator, or something with how it is wired, or something else totally.

I wonder, would you consider trying something like this:
https://www.amazon.com/Suacopzar-Switching-100V-240V-Universal-Transformer/dp/B0BK9GWX7Y/

This would give out 5 volts and enough current for sure. It would allow the regulator to be removed, at least to test if it is part of the problem.
If we had just the 5v power supply, the Waveshare board, and the Tonex connected, that should all work normally. Then we could look at adding other parts if you need (footswitches etc.)

I hope this helps. Sorry I am struggling to think of much else.

[extremesecrecy]

Ah, let me see if I can get my hands on one and test that. Thanks!!

…

On Wed, Mar 5, 2025 at 6:00 PM Builty ***@***.***> wrote: So when you connect the Tonex pedal to the Waveshare USB port, the screen goes black? That would suggest the power supply is not enough current, however from the specifications you have shown it should be plenty enough. Its really difficult to diagnose this kind of issue from across the world. It could be something with the regulator, or something with how it is wired, or something else totally. I wonder, would you consider trying something like this: https://www.amazon.com/Suacopzar-Switching-100V-240V-Universal-Transformer/dp/B0BK9GWX7Y/ This would give out 5 volts and enough current for sure. It would allow the regulator to be removed, at least to test if it is part of the problem. If we had just the 5v power supply, the Waveshare board, and the Tonex connected, that should all work normally. Then we could look at adding other parts if you need (footswitches etc.) I hope this helps. Sorry I am struggling to think of much else. — Reply to this email directly, view it on GitHub <#82 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACTTSQIY6CDUE2BE3ZLDDTL2S6T3RAVCNFSM6AAAAABX37R52CVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTENBQHA2DKOI> . You are receiving this because you authored the thread.Message ID: ***@***.*** com>

-- *Gabriel Hernandez* *4648 Merrick Court, Oceanside CA* Cell: 760-271-3708