Serial LCD firmware problem FRM010

[lrat]

Hi there,
This is my first mail to this forum; please be gentle
I bought the FRM010 kit(Serial LCD firmware) and I ran into a problem. I've installed all this on a prototype-board and have everything in place. However, there is no output signal at Pin 18. Instead of a high it shows a low on the probe.
I have tried to disconnect the variable potentiometer on this pin and it stays a low. Re-setting the circuit doesn't make a difference.
I have checked all pins and this is what I can see:
Pin1
Pin2
Pin3= Pulsating, incoming signal from Out0 from Picaxe 28X1
Pin4= High, goes low during reset
Pin5= Low
Pin6
Pin7
Pin8
Pin9
Pin10
Pin11
Pin12
Pin13
Pin14= High
Pin15= High and low (Pulsating at 4 MHz)
Pin16
Pin17
Pin18= Low
There is no reading on blank pins.
Shouldn't I read some pulsation on pin 16 as well? As this is the other input for the resonator?
I am puzzled. Everything else is working perfectly on my board. I've got a bank of LED's and a bank of Darlington drivers all working fine.
I would expect a high output on pin 18 but it's a low instead.
Any tips or hints are very welcome.
Kind regards,
Luc

 

[kevrus]

Firstly, welcome to the forum.

Pin18 should be 'high' as you say,even without an LCD connected.

Just a guess, but if the potentiometer was inadvertently incorrectly connected i.e. if the wiper of the pot was connected to pin18 and the pot turned towards the 0v connection (VSS), then you may have blown the output on the FRM010. May be worth double checking the connections.

Could you post a picture of your circuit, that sometimes helps.

 

[lrat]

Thanks Kevrus,
The moment I checked the status the output pin 18 wasn't connected to the trimpot.
I've ordered a new firmware chip from the UK and will replace it at the end of the week.
Thanks for your help.
It's a bit hard to send in a schematic as I'm working on it "on the go".
Kind regards,
Luc