More MCS+ Bootloader Questions

[milestag]

I am strongly considering buying MicroCode Studio Plus in order to use the bootloader with a PIC18F2525. But before I drop the $50...

1. Will the bootloader work without the MCLR/DTR line? I only need the circuit to look for the boot loader when it is first turned on (or manually reset). I don't have any "spare" pins in this design, and the MCLR pin is already being used as an Input, and even the USART RX and TX lines will be used as normal I/O lines for other functions when the bootloader is not connected.

2. Ideally I'd also like to skip using the MAX232 chip and just use 2 resistors as shown in the PBPRO manual (SerOut/SerIn). Has anyone had success with this for bootloader operation? Is it reliable?

thanks in advance

Jim

www.lasertagparts.com

[David Barker]

> 1. Will the bootloader work without the MCLR/DTR line?

Yes, it will work fine.

> 2. Ideally I'd also like to skip using the MAX232 chip...

MicroCode Loader uses the MCUs hardware USART, which operates in true mode. You will therefore need a level inverter of some kind in order to connect to a PC.

[milestag]

David,

Thanks for the info. I guess I'll just have to build a small programming "dongle" with the Max232 in it. Still better than adding an extra IC to every PC board.

regards,

Jim

[NavMicroSystems]

...I guess I'll just have to build a small programming "dongle" with the Max232 in it...

Jim, you can easily fit an SMD MAX233 inside a standard DB9 plug.

All you then need is four wires to your target board.

[keithdoxey]

I have a couple of these on their way to me

http://www.dontronics.com/micro-usb.html

which I am hoping will enable me to bootload my projects with just a USB lead as my Laptop is legacy free and it seems pointless to go

USB >> RS232 >> MAX232 >> PIC

when I can go

USB >> MicroUSB >> PIC

I also have a couple of these colour LCD displays coming as well

http://www.dontronics.com/micro-lcd.html

I hope to be able to create some pretty cool Menu's for my project

[NavMicroSystems]

Keith,

ok, we're a bit off topic, but

you should have a look at the LANTRONIX Xport

[Dick Ivers]

David,

You may consider this heresy but, ..... why not offer a version of Microcode Loader that operates from inverted logic? This may appeal to those not wanting a hardware interface, and maybe increase sales of MS+.

[picnaut]

Hi,

I may be wrong, but implementing inverted serial communication on the PC-side would NOT be an easy task. I have a feeling that it can't be done.
If it can, I'd love to hear about it.
It would be useful.

Cheers.