I have a MCUFRIEND 3.5" TFT ili9488-555 which is working very nicely but the shield takes up all of the pins on the Arduino.
I used i2c for a 2 line LCD and that was great. I would like to be able to have some pins left for a real time clock to run in conjunction with my TFT.
I found some projects for other TFTs to move to I2C but not for the ili9488-555
Can anyone point me to a project that might show me how to wire up i2c for the ili9488-555
thanks
I have published hardware fixes to remove the LCD_RST pin on the Mcufriend Uno Shield.
This lets you use I2C on A4, A5 on a Uno.
Of course you could use an SPI RTC.
David.
Dear David,
Can you inform me where I can find these published hardware fixes? I want to communicate via I2C with an Arduino that displays sensor stuff on a 3.5 inch TFT, so I need free pins A4 and A5
regards, Floris Wouterlood, The Netherlands
I just used the Forum Search "mcufriend snip A4"
It produced several hits. Mostly from me.
David.
Thank you david, I had read much of your stuff but was having some difficulty comprehending, finally sorted myself out.
I was reluctant to snip things that cost more than a dollar so I got some stackable headers, neet little buggers.
My TFT screen now works with some pins shuffled using david's mcufriend_kbv library and my TinyRTC runs on the i2c bus using the wire library.
Changes to the mcufriend_kbv library were ultimately very simple cribbed from david's advice in Pin conflict with TFT and I2C comms - Displays - Arduino Forum
MCUFRIEND_kbv.h
add
#define LCD_RESET 10
modify
//MCUFRIEND_kbv(int CS=A3, int RS=A2, int WR=A1, int RD=A0, int RST=A4);
MCUFRIEND_kbv(int CS = A3, int RS = A2, int WR = A1, int RD = A0, int RST = LCD_RESET);
The stackable headers let me branch off some power and reorganise the pins without snipping stuff I might want later.
Adding the source code for the TinyRTC board which came from http://henrysbench.capnfatz.com/henrys-bench/arduino-sensors-and-input/arduino-tiny-rtc-d1307-tutorial/ to the TFT source was easy no conflicts.
My clock now starts up every time with the correct time.
Now off to find the next problem!
Thankyou !
Have you not noticed that there are pins marked as SDA, SCL on the second Uno digital header?
The Mcufriend shield does not use these pins. So you can access them with male right-angle header pins.
You still need to get at VCC, GND for your RTC module. You can pick these up from the 3x2 ICSP header with a 6-way ribbon connector.
I use female headers on Protoshields to link regular Shields with STM32 or ESP32 modules.
Your stackable headers look a little risky. The stackable pins are not the ideal square cross-section that header pins are supposed to be. All the same, they are miles better than breadboards.
David.
I have an uno and a Arduino and actually used the Arduino with the headers, I tried solderding a couple of pins to my uno for the power and well lets just say my soldering is less than brilliant and it took me longer to unsolder the pins and get rid of the short, so, I figured the headers were safer.
Didn't know there was such a thing a 3 x 2 ICSP header with a 6 way ribbon connector, sounds fancy! Back to ebay.
I have now noticed the SDA and SCL on the uno , excellent, they weren't there when I looked before.
You have of course heard the joke about the guy using a brick to hammer in a nail and was asked why use a brick and not a hammer, he answered what's a hammer and where do you get one, I think that might have been about me.
thanks much !
