4.1 Introduction
The AKKON USB Controller Board is an electronic
device for the realisation of different tasks in the area of measunring,
controlling and regulation. The board is equipped with the PIC18F4550
micro controller with USB interface. The AKKON USB board can be
set up with different placement variants for different tasks. By
this way functionality of the board is very flexible an can be exploit
very good. By using standard dimensions new devices can be built
without a lot of effort.
4.2 Overview of
technical data
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48MHz clock frequency
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free assembler available
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different C-compilers available
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USB-Bus with 1.1 und 2.0-compatibility
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In circuit programming interface(ICSP) available
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USB-iInterface available
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I2C-interface available
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RS232 (Rx andTx) interface available
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power supply regulator on board
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17 digital buffered outputs
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8 digital inputes with PullUp resistors
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PWM output
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protected frequency input
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four digital output with led
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eight holes for mounting
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ease setup with different housing vaiants for rapid setup of
new devices
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Firmware updates over USB- ootloader (no further programming
device necessary)
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Dimension 120mm x 100mm
Further details can be found in the datasheet
4.3 Initial operation
Initial operation without bootloader
If the AKKON USB Controller Board is not equipped with a bootloader,
a programm loader software - called bootloader - has to be programmed
by a PIC programmer. This can either be done by putting the PIC18F4550
chip in the socket of the programmer or over the ICSP-interface
(In-Circuit Serial Programming-Interface) on J4. Please keep attention
on the right pin connection. The interface is not proteceted against
wrong connection. After successful programming, new firmware can
be programmed to the AKKON USB controller board by using the USB
interface. Firstly the PIC has to be in boot mode. The boot mode
can be switched by pressing the Reset Button (S1) while holding
the Firmware-Update-Button (S2) pressed. During that operation the
Leds on RD0..RD3 indicate the different operation modes by changing
blink frequency..
Initial operation with available bootloader
Detailed information how to program the PIC microcontroller on
the AKKON USB Controller Board can be found in the program file
directory. Please note that the CNC-Software AKKON can only run
with the special bootloader that will be provided by ordering the
AKKON USB Controller kit or the AKKON USB print & uP-version.
Further information how to proram the PIC microcontroller can be
found on the Microchip web page under:
http://www.microchip.com/stellent/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en021940&part=DM163025
(8th of October 2005). Information can also be found by searching
with the key words „PICDEM Full Speed USB“ on the microchip
web page.
Following the essential steps:
- connect AKKON USB Controller Board over USB cable with PC
- install USB driver
- switch AKKON USB Controller Board in boot mode by pressing
Reset button (S1) while holding firmware update button (S2)
- led RD0..RD3 will change its blink frequency
- upload test program „LedTest.hex" to the PIC
- perform further test programs
If a USB bootloader is already installed on the pic, uploads can
be done with the free available tool "PDFUSB.exe" available
on the Microchip web page
After that the AKKON USB controller board should now be ready for
operation.
4.4 Example
application CNC control
The AKKON USB Controller Board can be used with a MS-Windows PC
and a CNC control unit. For this reason the firmware AKKON CNC control
has to be uploaded to the AKKUN USB Controller Board. Furtheron
AKKON Desk has to be installed on a MS Windows PC (Windows 2000,
Windows XP). With the pre-programmed bootloader, programs can be
uploaded to the AKKON USB Controller Board very easy. AKKON CNC
can be used for stepper motors with 200 steps per rotation. Clock
frequencies are around 5KHz. This value can change if large amount
of data will be sent to the controller. Different machine parameters
can be set be AKKON Desk in the configuration files. The concept
of AKKON CNC is shown in figure 1.
click
here to view large picture
Figure 1: Control concept of AKKON USB Controlle
Board and CNC-Controller hardware
Please note:
AKKON Desk is currently in a beta phase and can be used by users
that have the AKKON USB Controller Board for free. Please note,
that the program can only run with the pre-programmed bootloader.
It can not be transferred to another PIC18F4550.
Further information about the AKKON CNC Controller Board can be
found here
4.5 Downloads
4.6 Product
configurationen
Variant 1: Print
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unloaded priont (dimensions 120mm*100mm)
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Documentation (schematocs, placement plan, part list, setup
and mounting instruction, small test program, source code of
modified bootloader in C)
Variant 2: Print and micro controller
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unloaded print (dimensions 120mm*100mm)
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PIC18F4550 with bootloader (enables to run free CNC-software
version of AKKON CNC)
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Documentation (schematocs, placement plan, part list, setup
and mounting instruction, small test program, source code of
modified bootloader in C)
Variant 3: AKKON USB controller board kit
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unloaded print (dimensions 120mm*100mm)
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all parts for seting up the AKKON USB controller board
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PIC18F4550 with bootloader (enables to run free CNC-software
version of AKKON CNC)
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Documentation (schematocs, placement plan, part list, setup
and mounting instruction, small test program, source code of
modified bootloader in C)
Remarks: Having the inital programmed
bootloader, the free software version of AKKON CNC can be executed.
This software will not run on other PIC18F4550. After rewriting
the inital bootloader AKKON CNC will not run!
Please note, I offer the PCB to my production cost as the board
has a small but in my opinion not important design failure. The
Sub-D plugs are located very closed together. Depending on the used
plugs it can be a problem to plug in both. But all pins are furthermore
assigned also to header pins.
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