OLED displat (axe133y) corrupt messages when starting up and sending serial data

J

jon_nic

New Member
hi,
I have just bought an axe133 OLEd 16x2 display and when i turn on it is supposed to say "serial OLED and www.Picaxe.com" as this is what is programmed in to the 18m2+ eeprom which came with the oled kit. however on power up it says "Sgpkcn ONGF and pifffk.coo" also when i try and send serial data at N2400_8 baud it also displays incorrect letters and symbols. i reprogrammed the 18m2+ chip with the AXe033 code from Picaxe.com but still same issue. since the eeprom data is not even displaying correctly on start up, could it be a faulty 18m2 chip?

anyone experienced similar issues?

regards Jon.
 
G

geoff07

Senior Member
Are you sending data to it immediately? If you neglect the pause before sending the first data bytes that can do funny things. Put a pause 500 at the start of your prog before the very first transmission to the display.
 
A

AllyCat

Senior Member
Hi,

Many of the faulty letters (I haven't checked all) are two above the correct one, e.g. LED becomes NGF. That strongly suggests that the Data 1 line is being held high. Either there is a "bridge" on a part of the D1 track to a supply rail, or perhaps there is a disconnection (e.g. missing solder joint or a broken track) allowing the line to float high.

Cheers, Alan.
 
J

jon_nic

New Member
Thanks everyone for their opinions. I checked continuity betweeen picaxe pins and the OLED pins and there was an open circuit due to poor connection on one pin, so after a resolder it now functions perfectly. Thanks again. Jon.
 
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