Bootloader for 16f87/88 that doesn't use UART

[mister_e]

Sure it exist or at least it could be done... as long as you're aware and you agree that the bootloader firmware will be way bigger and you're not code limited...

But... why you don't want to use the hw USART?

I saw once a 1 pin bootloader, and didn't used the HW USART, Wloader if my memory serves me well.

There's also that one using MCLR pin... omg, what was it's name... ZPBL or ZPL.

what i suggest is to look at TinyBootloader page, there's few suggestions over there.

[bcd]

Hi Steve,

Code space is not an issue. I cannot use the hw uart as I need it to generate rs485 at 250Kbaud ! On the PCBs it is wired as TX only, but even so I have not seen a half-duplex bootloader (please correct me, anyone..)

I looked at TinyBootloader earlier, but again it is tied to HW UART pins.

I'll keep looking. I found a mention on the Spark Fun site that bloader 1.6 could handle the 16f819, which doesn't have a uart. Maybe a bit iof creative code work is required...

bill

[dhouston]

Scroll to the bottom of the TinyBootloader main page and there's a list, with links, of other bootloaders, including ZPL and WLoader, which do not use the UART.

[ardhuru]

Very early on, Tony Nixon used to have just such a bootloader, RomZap. Not only could it use any pin, it also had an option to invert (or not) the signal, making it ideal for direct connection to the serial port. To my knowledge, development on this stopped a while ago, so I'm not sure about the support for 16F87. In case you are interested, I could mail you a copy, since Tony had kept it free.

Regards,

Anand