5V controller with 3.3V IO

[MJU]

What I really really want is a controller (AVR/PIC/PIC16..) that I can use with my Matrix Multiprogrammer boards (5 Volt), but use the IO's on 3.3V.
So the controller should only use 3.3 V on it's IO without levelshifters.

Someone mentioned the 16F1xxx PIC's but I can't see how I can use these controllers with only 3.3V IO..

So to be clear, I want to hang non-5V-tolerant devices on my multiprogrammer board (withoud level shifter of any kind).

[Benj]

Hello,

The latest v9 EB006 has a jumper on it to allow you to run the device from 5V or 3V3, the jumper also routes the power to the +V terminals. Note that reprogramming with the jumper set to 3V3 may not work and also the 3V3 supply is quite limited in terms of current it can supply.

Loads of 8-bit PICs will work at both 5V and 3V3 just check the electrical characteristics section of the datasheet.

VandSp.jpg (9.24 KiB) Viewed 5798 times

A lot of the 16-bit PIC devices require 3V3 but have some 5V tolerant I/O pins so you can stuff 5V onto the pin without risk of damaging it.

The 5V tolerant pins can be seen here in the device datasheet shaded in grey.

5VPins.jpg (55.11 KiB) Viewed 5798 times

[MJU]

Thanks BenJ but I'm an early Flowcode user so I have the earlier versions of the programmer.

Maybe with your influence you could ask the people @ Microchip to design a controller with the specs I asked for?

[Benj]

Hello,

Which version of the programmer do you have. It might be possible to disconnect the on-board voltage regulator by removing a jumper and add your own 3V3 regulator via the screw terminals to power the MCU at 3V3.

The version number is shown on the board as EB006-00-X where X is the version number.

I can certainly pitch the idea to Microchip but I would imagine my influence with them is extremely limited

[Jan Lichtenbelt]

I want to program the 16LF1847 microchip. The EB006-30-9 has the possibility to choose 3V3. However, in the list of microchips which can be programmed with this board, does not included any LF versions. I think that has been forgotten to mention.

But I have the older version EB006-30-6. If I understand Ben correctly, it is possible to program this 16LF1847 with this board. I looked into the electric scheme (see attachment) and found that the (PSU-USB) power jumper J29 in the scheme differs from the board. I think that there are 3 switches:
1) Vpp connected by Vppmain (13V) or USB(5V) for respectively PSU- or USB-position
2) PPP chip port A4 connected to USB(5V) or GND respectively
3) Screw Connector which is Vcc connected to voltage regulator 7805 (5V) or USB(5V) respectively

As far as I understand, to program the LF version microchips the last pinheaded #3 has to be removed and the 5V screw connector has to be powered with 3V3. Pin headers 1 and 2 has to be in the PSU position.

Is this correct?

With kind regards

EB006-30-6 Multiprogrammer.pdf

(915.36 KiB) Downloaded 305 times

Jan Lichtenbelt

[Benj]

Hi Jan,

It might work, it's certainly worth a go.

It might be that mLoader doesn't recognise the LF version ID, let us know if not and we can maybe try editing the script file to add the list under the same methods as the F version.

If mLoader doesn't work then you can always power the chip using the EB006 and program using the ICSP header and a PICkit 3.

[Jan Lichtenbelt]

Hi Ben,

That was exciting to try.
1) The EB004 (8 LEDs) has been connected to the EB006-30-6 board
2) The LEDs separately were tested if they work with 3.3 Volt. As expected they worked correctly.
3) With the microchip 16F1846 and with a simple Flowcode program the LEDs D0 and D1 are blinking
4) Now the header is set as described above and powered the IC with 3.3 Volt
5) Then the microchip has been replaced by the 16LF1847 microchip. But the Flowcode 7 with mLoader gave the error that the microchip could not be detected.
6) Then I tried to load the hex file into this chip by means of the PICKit 3 programmer (version 3.10) which succeeds now (USB directly into the PC, no hubs).
7) I tried also Flowcode 7 with PK3CMD.exe with parameters -P$(chip) -F$(target).hex -V5 -E -M or -P$(chip) -F$(target).hex -V3.3 -E -M for respectively 16F1847 and 16LF1847 microchips with in both cases the error code 1, Initialize failed!!!.
The conclusion is that programming the LF microchip version by means of Flowcode gives still problems, either with mLoader and EB006 board , neither with PK3CMD and PICKit 3 tool.
However there is a possibility to create a hex file which can be loaded into the chip by means of the PICKit 3 tool with PICKit 3 programmer or MPLAB IPE (usb not via hub).
It would be nice if you can manage mLoader to recognize the LF microchips on the EB006 board, if not to complicated.
Thanks for all the help

With kind regards

Jan Lichtenbelt

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