A tft addin for pbp3

[Aussie Barry]

Hi Richard,

I have had a small amount of success getting this thing going but still having a few problems.
Firstly, your .pdf circuit diagram appears to have another mistake (apart from the MCLR issue)
You show the LED connection on J2 as being Pin 9 however I believe it should be Pin 8 - or at least that's what is printed on the PCB silkscreen.
I made the necessary adjustments but still nothing. I am getting a nice 50% duty cycle PWM signal (~7.8kHz) on CCP1.
In frustration I connected the LED connection (J2 Pin 8) to the wiper of a 10k pot and adjusted it between 0V and 3.3V.
Once I got to around 3V the screen came to life - or at least half of it did
I think I might have a dodgy TFT screen.
I can see the elapsed timer counting and some of the reset button but most of the right side of the screen is scrambled with a big black ovoid shape in the middle.

Looks like I need to do another eBay purchase but don't really want to have to wait 3-4 weeks for it to arrive!

Thanks for all your help thus far. I will be in touch again once I have a new screen to play with.

Cheers
Barry
VK2XBP

[richard]

your right about the schematic I have uploaded a correct version , I have replaced the transistor with a pch mosfet (saves two resistors) but it still loses a little brightness and is no better than the transistor version

most of the right side of the screen is scrambled with a big black ovoid shape in the middle.

I had similar issues with mine , turns out the sil connector was very poorly soldered a bit of rework fixed it

[Gusse]

your right about the schematic I have uploaded a correct version , I have replaced the transistor with a pch mosfet (saves two resistors) but it still loses a little brightness and is no better than the transistor version

Thanks for the schematic update. Now I have to start gathering all needed components.
Why you have selected BS250, which has quite huge Rds(on), it is round 10 Ohm or more @3.3V. Why not go with a good PFET like IRLML9301TRPbF, which has ~100-200mOhm Rds(on) @3.3V. Also price is half of the BS250. With this FET you will not burn energy in transistor -> LED will be brighter.

[visnja30]

I tried to test the repetitively button, it works but not as expected.

When I touch the button the counter starts counting, and its value increases every 300ms for one and then suddenly accelerate and in few mS in increase his value very quikly and then slow down.

If it happens to someone else or just me?

[richard]

Why you have selected BS250

because it comes in a t092 package I can use in a breadboard for testing , yes a IRLML9301TRPbF would probably be better but they only come in a sot23 package.

visnja30 repetitively button, it works but not as expected

I would need to see your code to be sure ,button auto repeat works for me just fine . auto repeat won't begin until long_press_threshold has been reached and will repeat @ repeat_press_rate

these constants in the TOUCH_TFT.PBPMOD file control button timing . they may need adjusting depending on OSC and "gosub CK_BUTTON " loop rate

repeat_press_rate con 100 ;button auto repeat rate (must be less than long_press_threshold)
long_press_threshold con 300 ; min time for a BUTTON long press result
short_press_threshold con 20 ; min time for a BUTTON pressed result

[richard]

I put a bug in the CK_BUTTON: subroutine in the TOUCH_TFT.PBPMOD file , it stops a long_press being detected


should be this

IF button_count[the_button] >= long_press_threshold THEN

instead of

IF button_count[the_button] > long_press_threshold THEN

I will post a amended version when I finish getting the >64k code location problem solved for strings

[richard]

some updates

CK_BUTTON: subroutine in the TOUCH_TFT.PBPMOD file fixed
const txt strings can now be anywhere in addressable pgm memory
button txt strings can now be anywhere in addressable pgm memory


pin definitions for tft dc/cs/rst have been simplified
eg. for tft cs on bit 5 instead of tft_cs_bit con 32 is now

tft_cs_bit  con 5