A $40 32 bit ARM PCB with SD card and colour touchscreen included!

This looks like a winner

[cgi.ebay.in]

US40$ buys a compact PCB module with a

32bit ARM cortex m3 processor (100mips).
128k flash, 20k ram
High resolution 2,8 inch full color touch screen.
SD card slot.
Dataflash suport.
USB B plus.
RS232 DB9.
Standard spacing header type expansion connector for stepper drivers etc.
Jtag debugging
Non volatile serial port based boot loader.

Murray

Does it have analog inputs? I wasn't sure from the description.

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Too bad ! Can we see this board specs somewhere else ?

The processor does (STM32F103), but I don't know if the board exposes them.

Picking mine up at the post office tomorrow.

The product seems to be available from a number of sites.
Here is a youtube vid that appears to be the same board.
[www.youtube.com]

it appears that the manufacturer is www.powermcu.com

here are some other ebay postings that appear to be for the same board.
[www.ebay.com]
[www.ebay.com]
[cgi.ebay.in]



Here are some specs form the ebay site



STM32F103RBT6(development board ) with 2.8" TFT-module

On-board resources:

* CPU: STM32F103RBT6; (LQFP64-pin, on-chip integrated 128K flash, 20KRAM, 16Bit A / D; PWM, CAN, USB and other resources)

*With a 2.8-inch TFT true color touch screen module, color touch module configuration ADS7843 (or RSM1843 instead)

controller, support for a SD card (SPI mode) can be used to store pictures, in support of AT45DBxxx of a DATA FLASH (can be used for storage)

* USB interface, make USB experiment

* RS232 interface (ISP download), make RS232 communicate experiment

* AD adjuster

* standard ARM JTAG 20 pin

* A RTC in support, the four users LED lights, a power indicator light, a USB communication indicator, two user keys

* 8MHz crystal,32.768KHz crystal

* USB power supply or power supply by JLINK

* All I / O port through the standard pitch leads 2.54MM

* Board Size: 82MM X 55MM



2.8" 262k TFT[240*320] Color LCD module with Touch Panel on PCB (Rev:2.0)

2.8" QVGA 262k TFT-LCD module
240*RGB*320 pixels
8-bit or 16-bit parallel bus interface,8-bit mode use 74HC573 latch low 8-bit (short R7 enable 8-bit mode)
open R7 is 16-bit mode(default), use high 8-bit operation bus in 8-bit mode low 8-bit float
LCD driver is ILI9325
2.7-3.3V operating voltage
Resistive 4-wire Touch Panel integrated
RS1843 touch panel controller onboard directly compatible with ADS7843
Standard 2.54mm PCB headers for prototyping
Support a SD card interface
Support a ATMEL DataFlash AT45DBxxx series device

can directly use AVR,PIC,C51,ARM.STM32 MCU driver


I will report back when ive tested my board.

Murray.

Report Back.

The unit is indeed the one features in this youtube video [www.youtube.com].
The unit comes loaded with the firmware as shown in the video.
Firmware is compiled using a keil compiler (Windows, and I am assuming its a limited version)
A graphical library is provided but i am not sure about its license.
I suspect we will have to write all code from scratch using GCC so that it is truly open source.


Documentation comes on 2 small CDs and is mostly in Chinese. Fortunately cct diagrams are in PDF.


The SD card, touchscreen interface chip, a buffer, space for an 8 pin dataflash chip, and LED back light drive transistor and resistors are all mounted on the bottom of the screen PCB.

The main PCB is powered from the USB port and the board consists of
a linear 3,3v regulator
a stm32f103rbt6
a MAX3232 level converter (tx and rx only)
A USB-B interface.
2 push buttons (PA3) and (PA8).
2 LEDs (PA0) and (PA1).
A power LED.
a 32khz xtal and on the bottom a battery holder to power the chip's realtime clock.
a 20 pin JTAG connector,
a 32pin connector to the LCD board.
a side adj multiturn pot connected between 3v3 and gnd and connected to port PA2
a jumper selects between standard running mode and the bootloader.


Here are the pins for the user assigned connector (standard 0,1 inch pin spacing 26pin IDC connector)
unfortunately almost all the pins are shared with other functions on the board but where indicated may be isolated with a jumper

1 PA0 led
3 PA2 multiturn pot center
5 PA4 jumper to touch
7 PA6 jumper to flash and sd and touch
9 PA8 pushbutton to gnd 10k pullup
11 PA10 usart rx
13 PA12 usb +
15 PA14 jumper JTAG
17 PB0 jumper to touch
19 PB2
21 PB4 jumper JTAG
23 PB6 touch cs
25 3V3


2 PA1 led
4 PA3 pushbutton to gnd 10k pullup
6 PA5 jumper to flash and sd and touch
8 PA7 jumper to flash and sd and touch
10 PA9 usart tx
12 PA11 usb-
14 PA13 jumper JTAG
16 PA15 jumper JTAG
18 PB1 jumper to lcd
20 PB3 jumper JTAG
22 PB5
24 PB7 dataflash CS
26 GND


That leaves only 2 pins unused.
If the SD touch and flash are to be left out that will give us some more pins to play with but at the cost of sexy functions. I'd really keep the JTAG. it is very useful for debugging.

An afterthought:
The LCD can be set to be driven 8 bit wide, that can free up 8 lines, but would require the 8 upper lines to be clipped on their way to the display, and wires soldered on the bottom of the bottom board's IDC pin connections

A sexy unit, but a little short on pins for a reprap.

Murray.

Edited 2 time(s). Last edit at 09/27/2011 02:49PM by Murray.

I hate to play forum necromancer here, but this comment really fits well in this thread. There is a similar dev board with built in 3.2" TFT with touch, SD, STM32F103VCT6 (more memory), with 96 expansion pins... this should provide more options for connecting a handful of Pololus or Stepsticks and such, without having to disable onboard goodies to find pins to connect them to. I've got one on the way from China as we speak, and will post an update when I see how it will work out.

[www.aliexpress.com]

I'm hoping I can adapt the R2C2 source to this board without much trouble, then add in a nice menu system and graphical preview/progress display to take full advantage of the touch screen. I'll probably require .obj or .bmp files beside the gcode files to serve as previews, but may try running a marching cubes algorithm over the gcode file to directly convert it back to a mesh for previewing.

The progress display will probably be a progress bar to indicate how far up the Z axis it currently is, with a 2d rendering of the gcode path for the current layer, and the position of the extruder filling in that path in a second color.

Sometimes I can get a little over-ambitious on new projects, so we'll see how far I get on this one, but if it works out we may end up with a more featureful set of electronics than any other for under $100.

David Whittaker Wrote:
-------------------------------------------------------
> I hate to play forum necromancer here, but this
> comment really fits well in this thread. There is
> a similar dev board with built in 3.2" TFT with
> touch, SD, STM32F103VCT6 (more memory), with 96
> expansion pins... this should provide more options
> for connecting a handful of Pololus or Stepsticks
> and such, without having to disable onboard
> goodies to find pins to connect them to. I've got
> one on the way from China as we speak, and will
> post an update when I see how it will work out.
>
> [www.aliexpress.com]
>
> I'm hoping I can adapt the R2C2 source to this
> board without much trouble, then add in a nice
> menu system and graphical preview/progress display
> to take full advantage of the touch screen. I'll
> probably require .obj or .bmp files beside the
> gcode files to serve as previews, but may try
> running a marching cubes algorithm over the gcode
> file to directly convert it back to a mesh for
> previewing.
>
> The progress display will probably be a progress
> bar to indicate how far up the Z axis it currently
> is, with a 2d rendering of the gcode path for the
> current layer, and the position of the extruder
> filling in that path in a second color.
>
> Sometimes I can get a little over-ambitious on new
> projects, so we'll see how far I get on this one,
> but if it works out we may end up with a more
> featureful set of electronics than any other for
> under $100.

The interesting question would be, how many of those IO pins are still available with the screen attached??

I found what looks like the docs on it here:

[www.wayengineer.com]

If I counted correctly, it looks like it has 29 GPIOs, including 10 ADCs available... looks promising.

I bought one of these a while ago. I was hoping to use it as a graphical control interface for my R2C2 hardware (or something!), but I haven't done anything with it yet.

I have been working on the R2C2 firmware, which has not really been developed with portabiity in mind, so I would like to move it into a more portable state. There are several quite cheap ARM dev boards around, it would be good to be able to use these.

It would also be nice to have more open source code platforms available, so that these boards can be used more easily for different projects, without being tied in to particular vendors' tool sets.

Just a general word of caution on the CDs that comes with these Chinese boards, watch for viruses! I'm sure people do anyway.

I got my dev board and J-Link in, and am impressed by the micrium demo at least. I'm currently working on getting an open source toolchain based on ODev ( [www.stf12.org] ) set up, and will report back on how well that works with this board.

arm 32 has 6 pwm`s so how do we run a double extruder i believe we need 8 pwm`s

There is no need for any PWM. Bang-bang control is adequate for extruder and bed control and only gives a couple of degrees swing.

Edited 1 time(s). Last edit at 02/04/2012 08:41PM by nophead.

---

[www.hydraraptor.blogspot.com]

I bought one to play en test new id.

Std ramps or sanguilolu etc use:

1 PWM if just Extruder or 2 if heated bed.

Not 8.