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MicroBlocks

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Joined: 12/05/2012
Location: Thailand
Posts: 2209

Posted: 08:29am 03 Oct 2012

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I am in the final stages of designing a very small PIC32MX795 board.
It measures 50x49mm and breaks out all of the pins to headers, a few are used for onboard functions like sd card, USB and ICSP.
Every peripheral is available. Plan is to not use 'bitbanging' for anything and use the internal hardware.
Power connectors are lined up for use on a breadboard and when you use female headers prototyping fun can begin. :)

I would like it to run MMBasic, probably have to change a few port/pin numbers to get it working. The monochrome version would be easy as only one connector is then used up, the color version is better for desktop use (my son loves it). A version with just a terminal via usb and keeping all the ports available is very handy when interfacing to the outer world. Of course all choices are open so programming it with the ICSP using one of the C compilers from Microchip or others is possible.

I live in Thailand and am not so far from the Microchip factory. I decided to use my knowledge and location to start up a small business concentrating on modular boards that can be used for prototyping and as a 'unit' for final pcbs.

The plan is to make the modules as small as possible. These modules can then be 'dropped' on a pcb. The first ones will be breakoutboards so that these modules can be used for prototyping, size will be bigger to place headers. The 'drop in' for the pcb wil not have headers and can be a module on a small pcb or when more pcbs are needed can be used in the pcb layout.

The modules will be using I2C, SPI or serial. The first ones that will be made are a WiFi module, RTC, LCD, I/O expansion. Future plans will have optocouplers, relais, one wire and anything else i can imagine to be helpfull.
These extra modules will have their own mcu to take care of that particular function so that using them from the main mcu will be very easy.

The main mcu board has a 38 pin connector that can be plugged into a 'bus'. A small backplane print will be available so that building a small extensible computer will be possible. A small rack is in development.

The connector has +5v,3.3V,SPI,I2C,CAN,Serial,IO and the special feature of the PIC32 a PMP bus that has 16 bits address and 16 bits data highly configurable and with DMA. This will open up a lot of possibilities.

I will have my first bathc tested at the end of the month. I am busy getting the manufacturing bit under control, that is a part i have not much experience with, finding the right partners is costing a lot of time. However if it has some success i don't want to fail on being unable to deliver. So i will have to wait until all factors are known to determine a final price.

Edited by TZAdvantage 2012-10-04

Microblocks. Build with logic.

DuinoMiteMegaAn
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Joined: 17/11/2011
Location: Australia
Posts: 231

Posted: 09:48am 03 Oct 2012

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WOW ... your board size is only 2 inch x 2 inch

Closer PIC32 I/O pin inspection reveals that some/many of your PMP (parallel master port) pins conflict with those of the MaxiMite. Using MMBasic could be bit of a problem?

Edited by DuinoMiteMegaAn 2012-10-04

MicroBlocks

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Joined: 12/05/2012
Location: Thailand
Posts: 2209

Posted: 10:10am 03 Oct 2012

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A color maximite would not have any serial/spi peripheral available. A monochrome maximite (duinomite version) will have 2 spi, 2 serial or 2 i2c available.

However nobody will stop you using those pmp pins for other purposes. Like a can bus. :) :)
A can bus will make the PMP 8 bit instead of 16 bit, but it will still be usable.

It is just that if it has to be more open to other programming it is really essential to have the peripherals in the PIC available.

The only thing i really could not manage was using the same SPI port the maximite uses for the sd card. The traces would be all over the board, or the sd card had to be in the back. :)

Modifying MMBasic for that should be easy.

Microblocks. Build with logic.

DuinoMiteMegaAn
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Joined: 17/11/2011
Location: Australia
Posts: 231

Posted: 11:53am 03 Oct 2012

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Modifying MMBasic for that should be easy.

MMbasic is close source. Need to contact Geoff G.

MicroBlocks

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Location: Thailand
Posts: 2209

Posted: 10:41am 11 Oct 2012

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I exchanged some email with Geoff and a good point was that if it should be able to run MMBasic it should be easy to upgrade it with new versions without having to modify it every time.
I agree with that of course. The wish i have is that the board should be more open to other programming at the same time. The only way to accomplish that is to move the sd card to another board.
The rest can remain the same because no pins except the usb are used. The usb is wired exactly like a maximite anyway.
I am currently modifying the design to remove the sd card and replace it with a header.
I will make another small board that can be connected on the underside with all the maximite specific pins and connectors on it.
This will then result in a colour maximite clone with a size smaller then 2"x2".
You would then be able to design and prototype a system with a normal maximite for comfort (vga screen/keyboard,etc) and then drop this board in place to have 'product' freeing your maximite for the next project.
I have not priced it yet, but i think i can make these for 40$-45$.

Microblocks. Build with logic.

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