Has anyone worked with this screen before?
Private19872
Posts: 61
I recently bought this screen from Sparkfun. Once I plugged it in, it lit up and showed its splash screen, however, when I try to interact with it using my propeller, it doesn't recognize the serial commands I send. I set up this program very quickly to test it.
I checked it using the Parallax Serial Terminal, but it still doesn't seem to be doing anything on the screen. The screen's documentation says it uses 8 N 1 serial at a default of 115,200 baud. I'm wondering if I may have coded something incorrectly or just am using the wrong object for the job.
CON
_clkmode = xtal1 + pll16x 'Standard clock mode * crystal frequency = 80 MHz
_xinfreq = 5_000_000
OBJ
lcd : "FullDuplexSerial"
PUB Main
lcd.start(0, 1, 00, 115_200)
waitcnt(clkfreq+cnt)
lcd.str(string(124, 12))
I checked it using the Parallax Serial Terminal, but it still doesn't seem to be doing anything on the screen. The screen's documentation says it uses 8 N 1 serial at a default of 115,200 baud. I'm wondering if I may have coded something incorrectly or just am using the wrong object for the job.
Comments
It's not clear how the LCD's receive pin is connected. It may be that it's 3.3V tolerant (can accept a 3.3V logic signal), but you don't know that for sure.
FullDuplexSerial should work for this purpose provided the above hardware issues are addressed. More information on the serial display controller would be helpful.
The other way to boost the signal is to just use a 74HCT gate that is powered from +5V, maybe 2 inverters in series perhaps but they are quite happy to accept anything as low as 2V as a logic high. Of course 2 cascaded grounded-emitter NPNs will do the trick too if that makes it easier.
EDIT: anything lower than 5V will affect the backlight and display contrast but you should still see it operating anyway.