16F88 int-8MHz keeps retring, no download

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Post by riden » Thu May 04, 2006 7:34 pm

Sorry to hear that it still doesn't work. I know that I was able to download and run the hex file using the 16F88 bootloader with the 8Mhz internal oscillator.

It really looks like you are getting bi-directional data flow. I guess the next thing that I would do is to change the 2400 baud test program to echo the characters and burn the hex file directly into the chip (i.e. don't use the bootloader). You could then use the program to exercise the hardware to make sure that your serial port is operating properly. Naturally, you could also do the same thing using CCS C. You would want to set the program origin to 0 so the program will execute upon reset.

BTW, I received a reply to a post I made about port enumeration in Screamer that said that you can enter the COM port in Screamer v1.7. I'm going to give it a try later tonight.

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Post by lovefool » Wed May 17, 2006 8:54 am

I was busy to complete the main application. Now it looks working okay, so I came back to test this bootloader. I have checked several hardware, and found all of development boards don't connect CTS/RTS, only Rx and TX. Mine cable has CTS/RTS & DTS/DSR connected, so I may try just RX/TX connected.

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Joined: Sun Apr 30, 2006 10:02 am

Re: 16F88 int-8MHz keeps retring, no download

Post by lovefool » Tue May 22, 2012 2:10 am

It has been long time to use 16F88 again (same chip I used in 2006).

Currently I was working on 12F683 and wanted to debug online, so I ported program to 16FF88 and implemented several "printf" to show some value.
When I power up 16F88 and send welcome message to PC via RS232, every time first 2 bytes are corrupt. I have changed baud rate, adding caps for power supply, but no change. So I took 16F648A and loaded same software... now guess what? It works perfect. Same hardware, same software.

I think the UART part of 16F88 ( at least my lot ) isn't right.... that is why screamer didn't work 6 years ago.

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Joined: Sun Jun 10, 2012 6:12 pm


Post by kerwin11 » Sun Jun 10, 2012 6:55 pm

lovefool wrote:This is the log ... and checksum looks not correct

first line of SerialTest-88-Internal8MHz.hex is
PC > 0633 ACK+3
PIC>0F0054 0F00+T
PC > 3A08 0000 003F FF3F FF3F FF29 1A :08 0000 003F FF3F FF3F FF29 1A
PC > 3A08 0000 003F FF3F FF3F FF29 1A :08 0000 003F FF3F FF3F FF29 1A

PIC program:
1)Set baud rate 9600 (SBPREG=51)
2)Send ENQ(0x05)
3)Wait for ACK(0x06)
4)Read next character and set baud rate (SBPREG=0x33=51)
5)Erase memory
8)Send "T"
9)Wait for ":"
10)Read record length (1byte "0x08")
11)Read address high (1byte "0x00")
12)Read address low (1byte "0x00")
13)Read checksum (1byte "0x00")
14)Repeat read data for record length (8bytes "3F-FF-3F-FF-3F-FF-29-1A")
15)Calculate checksum (result is 0x05, not 0x00)

Does it work? i wlii try it after anyone has been successful! :lol:

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