New STM32F4 discovery board features TFT LCD

Tinito informs us that a new STM32F4 discovery board has been announced, featuring a 2.4″ QVGA TFT LCD (apparently without touch sensor), 64Mbit of SDRAM, a Gyro and all pins available through pin headers. The data brief is available for download and the board lists for $24USD.

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  1. And no availability ETA :-P

    One of the few Cortex M4’s w/ an external memory bus (I think it can execute from external memory as well)…

    1. What makes you say that/where did you read it? I can’t find anything about a touch controller or touch support, in either the part datasheet or the board’s.

      That said, the description of the preloaded demo from the board datasheet suggests some interface where there are multiple icons which -do things-. In the absence of multiple on board user buttons, that certainly suggests to me that touch is supported. But like I said, I cant find an official statement of that.

      1. Rodrigo is right: if you look into the User Manual UM1670m page 19, table 6, there is a “touch panel” using some pins, I also did miss this when firstly looked at the board.

        Can’t wait to get one ;)

      2. Ahh yeah look at that! If you look closely, top right of the LCD, that’s obviously a flex connector for a resistive touch overlay (4 contacts running to the 4 sides of the LCD overlay).

        Funny thing is, according to that table, it connects via I2C, but there’s no mention whatsoever anywhere else in the document of a touch controller.

    1. Even at $46 it would be a good buy. I wonder if they have a decent free toolchain and one that’s not ‘on-line only’, I really hate the idea of somethign so important only being on-line.

      1. Agreed! I will be picking one up. I’ve been happy developing for the stm32f4discovery (and other stm32 chips) with gcc, openocd and gdb. It is all free.

      2. The STM32F4 cores are pretty well supported by libopencm3 and Code Sourcery and summon-arm-toolchain both build working toolchains and openOCD supports the stlink natively now.

  2. A toolchain with eclipse, arm-none-eabi-gcc and openocd is pretty easy to setup.
    If you are looking for a ready-to-use solution, checkout ChibiStudio (from the ChibiOS/RT project), which off curse can also be used without ChibiOS. The windows version is available on ChibiOS website, while a linux version i did packaged some time ago can be found here:

  3. I’ve been using this free toolchain now for over a year:

    currently gcc 4.7-2013-q2-update release from the 4.7 series released 2013-06-28
    You can use newlib, hardware floating point, etc.
    No need for crippleware like Code Sourcery, or to build summon-arm-toolchain from source (though it’s educational).

    I will probably buy the latest Discovery just because…
    I wonder if the user usb supports HS (previous ones just supported HID and FS)
    A fair number of inexpensive baseboards/motherboards/accessories have also appeared for earlier versions. I hope Olimex puts out a couple nice STM32F429/427 boards.

    1. I can see there is only a STLINK usb connector on board, so there is even no FS to expect. beside HS, I suppose does mean High Speed (480mbps). but HS anyway needs a separate physical layer USB chip for addition to STM32F4 chip and most likely this is chip is not present on this board anyway, because this is STM32F4+LCD+SDRAM demoboard and there is no need for USB at all.

      but damit, I cant wait until it is on sale :)
      farnel somehow has set currently price to 21€ – what I dont believe to be a truth

      1. The data brief bullet-points “USB OTG with micro-AB connector”. Looks like the micro-usb is on the underside, sticking out at the bottom of the photo. With matching T/H mounting tabs on the topside, labelled USB USER. But like you said, the STM32F4 requires an external PHY for HS, and it seems unlikely they’d include one on this board.

        Have you seen the new USB MSP430 launchpad? It’s built to showcase a USB MCU but really does have only a single USB port up by the debugger. Looking at a photo of it really confused me until I realized there was a USB hub chip included in the debugger’s area of the board.

      2. I think Farnell’s 21€ will be accurate, as ST’s suggested USD price is $24. The placeholders for the STM32F429I-DISCO on element14 (a division of Farnell) and mouser show $42, which I think predates the later ST announcement. I think the ST announced $24 will hold, and the distributor prices will match that, as they have in the past.

    2. Thanks Jon, Yeah I would want something that was ready made, install and go and as simple and straightforward as possible. I really hate it when you go to get something installed and there’s all sorts of things to learn before you even know which files to download and then find “Oh, it needs XYZ and then you get XYZ and it needs UVW as well and … and so and in the end you give up and go with something else or forget the idea. I like the idea of the Mikro Electronica compilers, as although they aren’t free and aren’t cheap (well they are cheap compared to some!), it looks good and relatively straightforward, offers a choice of languages and some regulars here have indicated it’s pretty good.

      1. You’re just a touch off there, I’m well and truly past Arduino, but yes it’s good for beginners who want to go that way, even if (from what I hear) some of the libraries are so slow and bloated. I just want to get the job done with whatever micro I’m using, not muck around trying to make one thing play nice with another and learn all the innards of the compiler, etc. Unfortuantely many of the offerings don’t come in a simple ‘get the job done with no fuss’ type of package. So for those that want to play around with the toolchain and tinker and don’t mind spending time learning all that instead of getting on with their Micro project, then that’s fine for them, but I want to get the job done, have it run fast enough for the application, be stable, put it out there and ensure it works properly when it’s out there.

  4. If you want a good screen and a nice keypad, consider… a calculator. As a project.

    I look at this and I think of the new HP Prime, with an ARM9 CPU, currently about $180 US, and I wonder if you’re really getting value for the extra $156. Heck, even a Beaglebone Black is only about $45.

    I wouldn’t expect TI to hack profits from their calculator range, and HP have always been expensive, but ST could easily change their format to calculator-friendly. Clamshell design, LCD & battery in top half, CPU & keypad in bottom half, expansion pins to left / right of keypad makes a self contained unit.

    1. I’ve bee watching the HP Prime. Yes pricey, but consider all the applications available that are really optimized by target – and the documentation – and extensibility. So there is value added. But one can still argue an HP41x emulator may be a better approach. Hmmm…

      1. Anyone know: How to make a custom kepad?

        HP Palm – Love the idea, hate the baguette (french bread loaf) layout. If I could get custom key covers, and surface-mount key switches, I’d be designing my own low-profile keypad to go with an LCD module. Top side keypad, bottom side CPU / RAM / USB / LCD driver / power regulation / expansion port.

      2. I know this isn’t quite what you were after, but perhaps might be of interest.×4/dp/1774831

        You print up and slide in your required legends.

        You can get the touchpads custom made, but the only places that I know of aren’t at all cheap, though there will no doubt be somebody doing it cheap. I think in most cases people design the keypad on-screen and use the touch panel, though obviously that isn’t ideal for all situations.

    2. > and I wonder if you’re really getting value for the extra $156.
      Hi Alan, at $156 you get huge ammount of software work done by HP. Developing their (working) software alone is a huge task.

  5. Look at the document UM1670 and you see the STMPE811QTR resistive touch screen controller at 33. Alwesome board from ST. Can’t wait.

    1. Great find, thanks! Man, could they have buried the details on that guy any farther down into the document? I can’t help but feel like a quick pointer in the LCD section to “oh by the way there’s a touch screen, here’s how to talk to it” would have been a good idea.

    1. In what way do you define unusable for other projects? The LCD isn’t a serially-interfaced module? So?

      It’s certainly useable in any other project where you have an onboard LCD controller. Especially any other project that happens to use a STM32F4. What difference would it have made if it had an external controller? Surely it’d have been on the same PCB. Were you hoping for a removeable SPI-interfaced module?

    2. > Beware, the TFT controller is inside the STM32, and only pixel lines are connected to the
      > tft screen.

      You are talking about the tft controller included in the STM32. But beware: this tft controller is not used on the 32F429IDISCOVERY.

      Look in the UM1670 user manual, paragraph 4.8: the tft includes an ILI9341 controller. The ILI9341 has it’s own graphics ram inside, it is not mapped into the STM32 address space. It is connected to the STM32 via a parallel bus. The ILI9341 and similar controllers are common on cheap chinese tfts. So it is no problem to source similar tfts for your final product after developing on the discovery board.

      But it seems they raised the price, it is now listed for US$ 41.18 on the ST site.

      1. UM1670 in paragraph 4.8 also says that “The TFT LCD is a 2.41″ display of 262 K colors. Its definition is QVGA (240 x 320 dots) and is directly driven by the STM32F429ZIT6 using the RGB protocol”. ILI9341 has multiple modes of operation including direct RGB/HSYNC/VSYNC mode which bypasses internal GRAM. I don’t have the board yet but I assume display buffer is located in external SDRAM which is also on the board. The whole point of this kit is to show TFT and SDRAM interface in new STM32F4x9.
        This TFT can be reused in other projects without TFT controller since ILI9341 can be switched to parallel 8080 or even SPI mode!

      2. I’ve checked this discovery board firmware available from ST’s site (“STM32F429 discovery firmware package UM1662” number: STSW-STM32138, btw. finding it is a bit difficult – ST’s site is terrible):

        They are using FreeRTOS, FatFs, STemWinLibrary which is ST’s version of Segger’s emWin graphic library and STM32F4xx_StdPeriph_Driver v1.2.1 which includes F429/439 support (FMC, LTDC and DMA2D added).
        TFT buffer is located in SDRAM mapped by FMC to Cortex address space:
        #define LCD_FRAME_BUFFER ((uint32_t)0xD0000000)

        Three kits ordered from Farnell. Should be sent at Monday:)

  6. I feel that a spi or parallel adressable screen, yes, would have been more readily usable on another board. I just thought it was worth mentionning.

    But hey, that’s a demo board, so it’s probably not intended for reuse.

    1. The license (enforceable or not) basically say it is strictly for evaluation only, which kinda makes sense since at that low price it probably cost them money to sell it

      a framebuffer in main memory cost some overhead memory bandwidth, but for moving pictures
      there’s also something saved compared to pushing updates over a slowish serial/parallel bus

      1. The license for what? They can’t possibly license the hardware, that’s not a thing. Software/bootloader/whatever, though, they can.

        I suppose since it’s got an ST-Link on board, they could enforce that you aren’t allowed to use the ST-Link firmware for anything other than eval, thus by distributing the PCB in a finished product you’d be violating the license. But I think that’s actually also unenforceable too, though. I’m not an IP lawyer, but I think case law is that if you hand someone your iPod, they own all the music on it now too, seems like that applies here.

        Anyway, I think your BSometer is right, it’s probably not enforceable.

      2. I suspect that clause is also so they won’t get people raging at them because they integrated the dev board into some commercial product and ST then later discontinues it. That has unfortunately happened a few times in the past.

  7. I’m running the demo app right now. For thouse of you how were wondering wether the LCD has touch- it does.

      1. @octal
        An employee of ST Microelectronics gave it to me.

        By now its available at Digikey:
        Search for: STM32F401C-DISCO

    1. Can you have a look on the stm32f429 chip version? A or Y? Because version A have a dangerous bug for sdram.

  8. Check again martin. Those lines have pullups to vdd and are connected to cpu pins. I have this board for some time and I can confirm that lcd is driven by lcd controller from cpu and frame buffer is in external dram which is also on the board.

  9. Well even so that DMA2D stuff is geared towards displays with one address pointer. Try using it with displays with the x& y positions on separate addresses (like x add is 2A and y is 2B with base address of 0x6C000000 for commands and a offset of 4 for data ).. Wish there was and easy way of getting the DMA2D to work with different larger displays like the 640 by 480 of Newhaven’s
    Stmicro did not take that into account when they made the silly DMA2D library.. So much for using it for larger displays

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