Display TFT ST7789 (OshonSoft Basic).

[DogFlu66]

I leave the library to use ST7789 TFT display, I have translated one that is in C language. But unfortunately I have not been able to get it to work yet. I leave the files in case someone with more experience with these displays can review it.

 

[aliarifat794]

What hardware are you using? Aruino?

 

[DogFlu66]

I am using an Amicus PCB with a Pic18F26K22 microcontroller, the hardware is proven to work because I have downloaded the C language version and the TFT works.

I attach the C library used.

 

[DogFlu66]

This example with the basic configuration has been generated by an AI that I have been training for some time. It has not made a single syntax error but it does not work, I upload the files in case someone can review them.

 

[Ian Rogers]

How different is the ST7735, as on this very web site we did some super fast SPI read/writes
I used the Il92341 and Eric was using the ST7735 the code seemed to be very similar.

I have tried searching but it must be MUCH earlier than I remeber.. Cam was involved.

 

[camerart]

How different is the ST7735, as on this very web site we did some super fast SPI read/writes
I used the Il92341 and Eric was using the ST7735 the code seemed to be very similar.

I have tried searching but it must be MUCH earlier than I remeber.. Cam was involved.

Hi I and D,
First thanks D for starting this thread. I hoped for this.
I have some TFT displays, so I'll see if I can get results.

Here's what I think 'I' was talking about: https://www.electro-tech-online.com/threads/tft-lcd-projects-ideas-applications-open-discussion.152344/

If anyone is particularly interested in Nokia phone screens, Eric produce fonts for them, where he produced a choice of large and small characters also scrolling, but that may be on AAC. I can 'point' to it if asked, although the TFT screens are superior.
Cheers, C.
Here's a wiring diagram for PIC to TFT:

 

[camerart]

Hi,
It appears that my 'old' tft screens need level shifters, so not a good start.
I've ordered some later SPI ones.
C

 

[Nigel Goodwin]

Hi,
It appears that my 'old' tft screens need level shifters, so not a good start.
I've ordered some later SPI ones.
C

Most TFT screens are 3.3V, so you can either run your system at 3.3V, or add a 3.3V/5V converter - or you can buy TFT's with built-in converters, it's not a question of 'age', it's just a question of ordering the correct one for your needs.

 

[camerart]

Most TFT screens are 3.3V, so you can either run your system at 3.3V, or add a 3.3V/5V converter - or you can buy TFT's with built-in converters, it's not a question of 'age', it's just a question of ordering the correct one for your needs.

Hi N,
I used the term 'old' meaning I bought them when I was young.

I ordered new SPI ones, for simplicity.
C

 

[Nigel Goodwin]

Hi N,
I used the term 'old' meaning I bought them when I was young.

I ordered new SPI ones, for simplicity.
C

Weren't the old ones SPI? - or had you specifically bought a different type?.

 

[DogFlu66]

I'm still working on the subject, but I found that the tests are not good because the micro I use at 64Mhz internal clock when used from 16Mhz and consecutive pins of the same port are controlled (for example: PORTC.0 = 1, PORTC.1 = 0, etc) as outputs fail and do not stay at the designated value.
So I have ordered other micros to replace them, although there is no problem in using the old micro with lower clock speeds or adding a NOP after each PORTx.x and it works perfectly at any speed. Unfortunately I dismantled the display before knowing this and started with other things so I have postponed it for September. But I was also waiting for two suggestions for improvements to the compiler, one of which has already been incorporated and is that functions allow more than 5 input arguments, currently up to 30, and another of lesser importance and is that tables can be made with a greater number of elements, at least 255, which until now is limited to just over 100.

 

[camerart]

Weren't the old ones SPI? - or had you specifically bought a different type?.

Hi N,
At the time I bought them, I don't think I knew what SPI was. I just looked around and bought them from 'Open-smart'. I looked at them today, and I doubt they are SPI. I don't want to add comlication, so I just bought SPI ones. Should be here in 6 weeks
C

 

[camerart]

I'm still working on the subject, but I found that the tests are not good because the micro I use at 64Mhz internal clock when used from 16Mhz and consecutive pins of the same port are controlled (for example: PORTC.0 = 1, PORTC.1 = 0, etc) as outputs fail and do not stay at the designated value.
So I have ordered other micros to replace them, although there is no problem in using the old micro with lower clock speeds or adding a NOP after each PORTx.x and it works perfectly at any speed. Unfortunately I dismantled the display before knowing this and started with other things so I have postponed it for September. But I was also waiting for two suggestions for improvements to the compiler, one of which has already been incorporated and is that functions allow more than 5 input arguments, currently up to 30, and another of lesser importance and is that tables can be made with a greater number of elements, at least 255, which until now is limited to just over 100.

Hi D,
As you can see above, I've ordered some screens, which may be a while.

I have PCBs for an other project with 18F46K20, that have Nokia screens, which are SPI, and I don't think it will take much to wire up the TFT screens in their place.

Also I can use the programs I have that with your modifications will make it a little easier for me to read than yours, so I may be able to help a little or just test what you do.

These PCBs have 8mHz crystals X4 PLL.
C.

 

[DogFlu66]

I use a lot of that same microcontroller but ending in 22, which is the same as the 20 but with more memory. I use it at 16Mhz x 4PLL with internal clock.

I have taken advantage of an order of components for work and I have added a pair of Pic18F26K22 which are the ones I use at home, and it is the one that fails me from 16Mhz, and which I use at 16Mhz x 4PLL. But in my case they arrive in just 3 days because I have ordered them from Farnell Spain.

 

[camerart]

I use a lot of that same microcontroller but ending in 22, which is the same as the 20 but with more memory. I use it at 16Mhz x 4PLL with internal clock.

I have taken advantage of an order of components for work and I have added a pair of Pic18F26K22 which are the ones I use at home, and it is the one that fails me from 16Mhz, and which I use at 16Mhz x 4PLL. But in my case they arrive in just 3 days because I have ordered them from Farnell Spain.

Hi D,
Supposedly, the internal clock is fine, but I had issues many years ago, so I added XTLs, and now I don't get clock issues any more, but my max is 32mHz. I'm no expert. I think both sppeds will be ok.
C

 

[Nigel Goodwin]

Hi D,
Supposedly, the internal clock is fine, but I had issues many years ago, so I added XTLs, and now I don't get clock issues any more, but my max is 32mHz. I'm no expert. I think both sppeds will be ok.
C

Using TFT's requires the highest speed you can get, and running the SPI as fast as the TFT will stand - however, running the PIC at 64MHz may require backing the SPI speed down a notch, as they are somewhat limited.

 

[camerart]

Using TFT's requires the highest speed you can get, and running the SPI as fast as the TFT will stand - however, running the PIC at 64MHz may require backing the SPI speed down a notch, as they are somewhat limited.

Hi N,
Ok! I guess that they will run slower, but not efficiently, is this correct?
C.

 

[Nigel Goodwin]

Hi N,
Ok! I guess that they will run slower, but not efficiently, is this correct?
C.

If you run them slower, the display updates slower, and there's a considerable amount of data to transfer to a TFT - the small Nokia LCD displays are far easier, as they are only B&W, and much lower resolution, so updates are much faster.

 

[camerart]

If you run them slower, the display updates slower, and there's a considerable amount of data to transfer to a TFT - the small Nokia LCD displays are far easier, as they are only B&W, and much lower resolution, so updates are much faster.

Hi N,
Ok, that's fine, at least I'll be able to test 'D's CODE.
C

 

[Nigel Goodwin]

Hi N,
Ok, that's fine, at least I'll be able to test 'D's CODE.
C

They even work using software SPI, but the speed is appalling

It is useful though for testing purposes, or when you inadvertently allocated the PCB SPI pins to non-SPI pins on the PIC, while you can allocate most peripheral pins to various of the physical pins it's not universal, and varies from PIC to PIC.