Deviation on STM32F103RBT6 development board?

I have a Devo 7e running Deviation, and I'm very happy with it for what it is. I have done the diode mod, add 3in1 mod, and the 2x3 switch mod. I also have a HK-T6A with a USBASP-based PPM to HID encoder in it But I want to make something custom, lighter, with better gimbals.

Would it be reasonable to get Deviation running on a STM32F103RBT6 development board? rc.fdr.hu/devo.php#devo7e says that's the same kind of STM32 used in the Devo 7e. Dev boards with color touch screens are available on eBay for $25. The display code would I imagine have to be rewritten for the ADS7843 instead of NT7538, since the display controller differs. The unit comes with a 2.8 inch 320x240 display with a touch overlay.

I am not averse to adding an I2C ADC if necessary... and if code space permits...

Would it be smarter to not bother, and just to target a better CPU? I see that there was an effort to do that previously, but it stalled. I imagine it would be easier to use an already-supported STM32, though

Google brings people to all pages, if their search terms are specific enough

Packages with STM32F103VCT6 board+LCD (QVGA touch) begin at $40, which is not too awful. But the STM32F103RBT6 can be had with a display for $25, which is a lot more inspiring. On the other hand, maybe there's not enough room in the RBT6 to run a fancy display anyway. Is it just not realistic do it with the RBT6?

I have just ordered a dev board with a STM32F103RBT6
and another with a STM32F103RCT6

Hoping I can get at least one of those working well enough to transplant into a TX I want to Deviate

Neither come with screens - but they were only £6 and £8 each

I'm not a programmer or a hardware guy to any real level..but willing to tinker and learn as I go

Will report back when they arrive

Regards
Rob

I'm thinking about pulling the trigger on one of these Sainsmart STM32F103VCT6 boards with 3.2" touch TFT display.

The display controller is SSD1289 and the touch IC is XPT2046. Controlling the display seems to be fairly well-explored territory. Likewise for the touch controller.

www.sainsmart.com/sainsmart-stm32-stm32f...serial-jtag-swd.html
www.ebay.com/itm/STM32-STM32F103VCT6-Boa...9:g:21YAAMXQwKdRejdm
www.amazon.com/SainSmart-STM32-STM32F103...ywords=STM32F103VCT6

www.hotmcu.com/32-touch-screen-tft-lcd-w...-interface-p-36.html
www.solomon-systech.com/en/product/displ...-controller/ssd1289/
www.gpegint.com/files/library/files/supp...r%20IC%20SSD1289.pdf
github.com/notro/fbtft/wiki/SSD1289

ldm-systems.ru/f/doc/catalog/HY-TFT-2,8/XPT2046.pdf

Please stop me now if there's some obvious reason why I am unlikely to be able to implement on this

Deviation uses libopencm3 for a hardware abstraction layer. When you say the display/touch controllers are "well explored", have you verified that that was done with libopencm3, and not some other HAL - for instance, any of the official HAL's from STM? I don't see it in my copy of libopencm3.

No, I sure can't verify that. As far as I know nobody has done it with libopencm3. Besides Arduino-specific stuff, what I came up with was

github.com/LonelyWolf/stm32/tree/master/SSD1289
and
libstock.mikroe.com/projects/view/1837/s...display-library-demo

Having looked at the latter example code side by side with the Deviation code (I am currently examining deviation-master\src\target\devo10\lcd.c, pardon my backslashes but I'm on wintendo right now, vs. SSD1289.c) the differences seem quite translatable. Deviation has LCD_Init(), the lib has TFT_Init(). Deviation uses rcc_peripheral_enable_clock() and gpio_set_mode() (are these libopencm3 functions? edit: yes they are.) while the lib uses GPIO_Clk_Enable() and GPIO_Config(). This code was designed for STM32F103RCT6; the STM32F103VCT6 has more GPIOs. I am optimistic about being able to get LCD working.

I haven't looked at touch yet, but the LCD looks totally doable. Not quite copy and paste, but doable.

www.hotmcu.com/hyministm32v-dev-board-32...-p-5.html?cPath=1_20

most relevant there is the schematics.

dev board: www.haoyuelectronics.com//Attachment/HY-...Y-MiniSTM32V_SCH.pdf
lcd board: www.haoyuelectronics.com//Attachment/HY-...STM32V/HY32D_SCH.pdf

Now the question becomes, are there enough of the right kinds of pins free, or at least employed on a useful bus upon which we can piggyback. Stop me if I'm wrong, but from the board schematic it appears that the following pins are free:

PA0-PA3
PB8-PB15 (includes available I2C and SPI)
PC0-PC7 (includes ADCs)
PE0-PE6

This sounds like enough free pins to implement the radio (That's SPI, right?) and plenty of inputs. Am I on track?

I finally got the hardware. I am working on the lcd driver support.

More comments in the deviation source code would not have gone amiss.
What does LCD_DrawStart do? LCD_DrawStop? LCD_DrawPixel?

I get LCD_Init and LCD_DrawPixelXY, those have names that make sense. But everything I do with the panel is either initializing or drawing, so the other functions are not as self-explanatory.

I can probably figure it out but some help would be appreciated as it would save time.