EasyPIC-V8 Level Shifters

[Gronque]

The EasyPIC V8 uses two level shifters to program and debug PICs running at 5V and on the schematic we see that the direction is controlled by the signals PTB21-PGD_DIR and PTB22-PGC_DIR but we don't see where they come from.

Do they come from the CODEGRIP?

If yes, it would be possible to use a similar circuit with a CODEGRIP module to program and debug a PIC based PCB supplied at 5V but then how do we generate the two direction control signals mentioned above?

[IvanJeremic]

Hi,

PTB21-PGD_DIR and PTB22-PGC_DIR are coming from CODEGRIP.

If you are using a standalone CODEGRIP then you can use these signals with no problem, everything is already set.

If you are trying to use it from EasyPIC v8, i do not think it will work, since the external programmer connector is meant for using it on a MCU on the EasyPIC board not the CODEGRIP from the EasyPIC board on some other board.

Regards,

Ivan.

[Gronque]

Hi Ivan,

These signals are not indicated on the pin-out diagram supplied with the CODEGRIP.

Where are they connected?

Thanks

Gronque

[Gronque]

Hi Ivan,

Any news?

Thanks

Gronque

[Gronque]

Hi Ivan,

Any news?

Thanks

Gronque

[Gronque]

My question should be easy to reply for anyone at MikroE.

Why this silence?

[IvanJeremic]

Hi,

Sorry for the delay.

They are coming from the PGD and PGC pins.

So basically the same pins that are sending the PROG_PGC and PROG_PGD, from the EasyPIC v8 schematic.

Regards,

Ivan.

[Gronque]

Hi,

Thanks for the reply.

Could you double check that information?

Won't the signal received by the CODEGRIP oscillate when the MCU is in high level?

Regards,

Gronque

[IvanJeremic]

Hi,

I spoke with one of the developers, the pins come from CODEGRIP device they are part of the internal structure of the CODEGRIP programmer and that is not public information so i can not share it.

Regards,

Ivan.

[Gronque]

Hi,

So there is no way to program and debug a PIC running at 5V with the CODEGRIP?

That is rather disappointing!

Is there other options?

Can MicroC pro program PICs using a programmer from an other manufacturer?

Regards

Gronque.

[filip]

Hi,

Of course you can program and debug the PIC powered by 5V, these level shifters are used to support both 3V3 and 5V.
Direction signals are used to set the programming pins communication direction (input or output) which is controlled internally by the CODEGRIP.

Regards,
Filip.

[Gronque]

Hi,

Your reply is not coherent with the previous discussion.

In the EasyPIC V8, the level shifters are external to the CODEGRIP that is installed on the EasyPIC V8. Yes it can program and debug PICs powered at 5V but I need to program and debug PICs powered at 5V using the CODEGRIP alone, without the EasyPIC V8. The CODEGRIP doesn't have integrated level shifters so I will have to install level shifter between the CODEGRIP and the PIC. These level shifters need direction control signals. These direction control signals cannot be the PROG_PGC and PROG_PGD from the CODEGRIP, it will not work when the PIC is transmitting it will oscillate on the side of the CODEGRIP.

On the CODEGRIP Adapt v100 schematic there are two signals named P7 and P9, perhaps these can be used/programmed as direction control signals?

If not, can MicroC pro program PICs using a programmer from an other manufacturer?

Regards,

Gronque

[filip]

Hi,

I have just tried programming 18F4550 using CODEGRIP on breadboard, externally supplied with 5V and it works just fine.
Currently, you can set board voltage in the CODEGRIP application up to 3.3V only, it cannot provide 5V at the moment.

Regards,
Filip.

[Gronque]

Hi,

This matches what I observed.

The PIC must be powered by the CODEGRIP.

The CODEGRIP will supply up to 3.3V.

In my case, I cannot debug with the CODEGRIP because my board has to run at 5V.

I have to run a cable from the EasyPIC-V8, it looks a litle "Mickey Mouse" in the field...

On the CODEGRIP Adapt v100 schematic there are two signals named P7 and P9, perhaps these can be used/programmed as direction control signals?

If not, can MicroC pro program PICs using a programmer from an other manufacturer?

Regards,
Gronque

[Gronque]

Hi,

It's been almost a month since my last post and no questions have been answered.

Please make corrections if anything is wrong in the following statements:

1- The CODEGRIP does not have internal level shifters.
2- That mean that it cannot communicate with an MCU running at 5V.
3- In that case, It can program the MCU only if its 5V is off and if it is supplied by the CODEGRIP.
4- The CODEGRIP cannot provide more than 3.3V to the MCU.
5- That mean that the CODEGRIP cannot debug an MCU running at 5V.
6- Level shifters could be added to the application PCB but they will need direction control signals.
7- These direction control signals must come from the CORDEGRIP.

To enable any progress with that issue, these questions need to be answered:

1- On the CODEGRIP Adapt v100 schematic there are two signals named P7 and P9, perhaps these can be used/programmed as direction control signals?
2- Can MicroC pro program PICs using a programmer from another manufacturer?

Regards,
Gronque