Trace is fine but 0v showing Trigger level readout

[johnnt]

Hi folks,

Just built a DSO0138 which i purchased from banggood.

It all seems fine and all the reference voltages seem to check out (although a couple of the voltage dependant ones are a bit high but i'm using a 12v suuply).

The problem i have is the trace appears fine but i get a 0v reading on the trigger level readout. Is there a pin which feeds this, or is it extrapolated from the probe measurements?

Thanks

John

[johnnt]

No replies - surely someone must have some advice.

What feeds the trigger level readout - the voltage must be available to the device as the trace is accurate, just the readout shows 0v all the time.

Anyone got any pointers??

Thanks

J

[MNTech]

The trigger level is a control you set. Hit the SEL button to move the highlighting to the pointer on the right side of the display.
Then use the + and - buttons to change the position of the pointer and the voltage reading.
Holding the OK button for 2 seconds will reset it to 0.

Set the trigger pointer to a level that gives stable triggering, usually halfway between the highest and lowest voltage swing.
On an AC voltage 0 volts is the center, with DC pulses you have to change the level.
The slope selection determines if the scope triggers on the rising of falling edge of the waveform

[johnnt]

err, ok how stupid do i feel right now !

At least i know my soldering's ok !

Thanks for the info.

J