Matrix user forums

Posted: **Mon Apr 11, 2011 12:19 pm**

Article: https://www.matrixtsl.com/resources/get ... .php?id=54

If you have any questions for the author or comments on the article, please post them below.

Posted: **Mon Jan 23, 2012 5:42 am**

i have a question on this, i made a few programming boards which hook to the pickit2, then i noticed for the chips 16f1938 and 16f1939 they have a max vpp of 9v not 13.5v, microchip provides a special circuit diagram using the lm431 in the datasheet, the problem is i made as per datasheet in the icsp part and it pulls the vpp down on both side of the resistor, so it pulles the vpp output inside the pickit2 down to 9 volts as well, is this acceptable? what would be a better alternative, would a high value resistor of 100k and a simple 9v zener be suffice,im not sure what the current rating of the lm431 is as minimum ratings to reliably operate,.... to be honest i've been programming these chips with 13.5v vpp and nothing has ever happened to them, i've programmed one of them at least 100 times and still operates flawlessly, what are your thoughts on this?

Posted: **Mon Jan 23, 2012 11:18 am**

Hello,

I don't think the PICkit 2 supports the devices that reprogram at 9V at least according to MPLAB. I think this was one of the reasons that Microchip released the PICkit 3 so they could reprogram at different voltages.

I always use the standard ICSP circuit (without the lm431) and this is working great with the PICkit 3 device and the 16F18xx and 16F19xx devices.

Also I have reprogrammed these devices at 13.5V and had no negative implications so far.

Note that the Matrix hardware such as the EB006 and the HP488 boards all program at the DC supply voltage though you will receive an error if this voltage is less then 12V.

Posted: **Mon Apr 02, 2012 8:08 pm**

In the article MX-007 “From idea to working model” different type of breadboards are given for 18 pins microcontrollers of the microchip 8-bits series 16Fxxx and 18Fxxx.

The advantages of this new breadboard are:
- A semi-professional type board
- On-board programming (IC stays on board)
- LCD connector for easy testing.
- Optional on board power supply

In the meanwhile the 5x5 cm breadboard has been improved to a semi-professional one (excepted the distances to the board edge). This board can help you to realise easy your own model with one of the 18 pins microcontroller.

See the complete text in the word document attached.

With kind regards

Jan Lichtenbelt

PS. I'm sorry, but .pcb file were not allowed to be uploaded. The breadboard PCF file is therefore attached as .txt file. Change this into .pcb file.

Posted: **Sun Apr 22, 2012 8:11 pm**

This double side breadboard for 18 pins microcontroller with LCD connector, on board AC/DC powersupply and ICSP is available from the autor. The size is 5x5 cm. Additional V+ and B6 are available on the subD-9 connector. On board programming with ICSP can easy be done with the main board EB-006 and PICkit2 or 3. Part of the power supply can be deleted/short circuited, if wanted. During programming V+, A5, B6 and B7 are disconnected form the rest of the board.
This is an improved version of the previous one, described here above.

Kind regards

Jan Lichtenbelt

Posted: **Mon Aug 11, 2014 11:34 am**

Always trying to get the best solution, I'm glad to announce an improved breadboard for 18 pins microchips.

The improved version is 12A and 12B.

The following Microchips can be used
PIC16F54, PIC16F1826, PIC16F1827, PIC16F1847, PIC16HV540, PIC16F627A, PIC16F628A, PIC16F818, PIC16F648A, PIC16F818, PIC16F819, PIC16F87, PIC16F88, PIC16F84A, PIC18F1220, PIC18F1230, PIC18F1320, PIC18F1330
with the remark that the numbering of the PIC18 deviates from the PIC16, but the ICSCP are always at the same pins.

The specifications of version 12B are
1) the board can be used with and without power supply (AC or DC)
2) A matrix of 16x18 whole is the standard, but not all of them are available.
- Column 1 and 18 are all GND
- Column 2 and 17 are +5V from rows 1-13
- Columns 8-11are mainly used by the microchip
- Columns 7 and 12 are connected with the corresponding microchip pins, except the ICSP pins of the microchip. These last pins can be connected or not depending on the 5 pins header (on top of the microchip)
3) Standard available
- ICSP for programming the chip, with automatically disconnecting electronic to the applicable pins
- sub-D 9 pins connector with all B0-B7 ports and GND, or B0-B6 ports , 5V+ and GND, depending on a 2 pins header (between the sub-D connector and the microchip)
- Facultative a 16 pins LCD connector can be placed on column 3 (see picture)
- If the Sub-D connector is used for LCD, ports B6 and B7 are available for IOC, total 2 ports.

The specifications of version 12A are
All the same specifications as version 12B, except in version 12A ports A0-A3 are connected to sub-D pins 1-4. In version 12B ports B0-B3 are connected with sub-D pins 1-4.
That means that in version 12A ports B0-B3 are also available as IOC ports, total 6 ports.

Interested? Contact me.

With kind regards

Jan Lichtenbelt