Emon - Is your LCD glitching?

LCD connected to an Emon circuit!

You are seeing your LCD going to weird ascii. This happens when a mains load causes a superfast transient to spike the LCD logic.

Serial monitor is unaffected - but you need to reset to clear the lcd glitch.

This is a solution.

Power Supply
12Vdc to Vin.
5Vdc (fed from 12Vdc regulator or another 5Vdc regulator but common ground) feeding 5V sensor bias for voltage and current.

5Vdc FROM your uController board (dont use the same 5Vdc supply to your sensors) to LCD.

LCD - place a 1K resistor in the enable line. Note, I haven't tested the issue using an I2C LCD or an I2C backpack (adafruit)- it might also solve this glitch issue.

This setup will stop transients from mains switching glitching your lcd.

As this site does not have reply notifications, I might not reply for a while if there are any questions- see how it goes.

Robert Wall's picture

Re: Emon - Is your LCD glitching?

Are you using the standard OEM hardware - emonTx and emonGLCD - or your own pcb or breadboard? I think it would be helpful if you could make that clear, and provide before and after circuit diagrams of the set-up that suffered the problem.

platypus's picture

Re: Emon - Is your LCD glitching?

Using this config - http://openenergymonitor.org/emon/buildingblocks/measuring-voltage-with-an-acac-power-adapter

but modified for 15Vac feed - 100K/6K8 with 430K/430K bias. CT cct used 100K/100K bias.Capacitors 10uF/63V

20x4 character lcd (white/blue) from Adafruit

standard liquidcrystal library to run lcd


lsant232's picture

Re: Emon - Is your LCD glitching?

Please help me to find these code.

Robert Wall's picture

Re: Emon - Is your LCD glitching?

If you say what "these code" is that you cannot find, someone might be able to help you.

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