Help with flashing serial firmware

[PaulAntonDeen]

First time working with avrdude here. I need a little help, I understand that if there is a bootloader on this thing than I can flash with an FTDI cable...is there?
If not, I need an AVR programmer: i just ordered an USBasp to be sure.
Is there a little tutorial using windows or mac on how to flash the .hex file for serial communication? I see way too many options and documentation online. I don't fully understand what fuses are yet and if they need to be done in seperate commands or can be included in the flash command. So some orientation is much appreciated!

[gcormier]

There is no bootloader so you need an AVR programmer.

Some info here
#49

Also here
https://github.com/gcormier/megadesk/blob/master/DIY.md

Windows sample file to flash
https://github.com/gcormier/megadesk/blob/master/flash.bat

I do need to upload my linux script, but this will get you started, this is for the Pololu AVR programmer. If you comment/enable the respective lines it should work

#!/bin/bash
# Pololu
PORT=`pavr2cmd --prog-port`
PROG=stk500v2
pavr2cmd --freq 114
# End Pololu

# avrisp
#PROG=usbtiny
#PORT=usb
# end avrisp


MCU=attiny841

while  :
do
pavr2cmd --freq 114
avrdude -c $PROG -p $MCU -U lfuse:w:0xe2:m -P $PORT
avrdude -c $PROG -p $MCU -U hfuse:w:0xd6:m -P $PORT
avrdude -c $PROG -p $MCU -U efuse:w:0xfe:m -P $PORT

avrdude -B 0.5 -c $PROG -p $MCU -V -Uflash:w:megadesk-v2022.03.hex:i -P $PORT  

read -n 1 -s -r -p "Press any key to continue"

done

[PaulAntonDeen]

Thanks I'll give it a shot and close this one if I can make it work :)

[gcormier]

Sounds good let me know if you have any issues.

[PaulAntonDeen]

Got Zadig to install the device driver for the programmer: https://quadmeup.com/working-solution-for-usbasp-driver-in-windows-10-64bit/
Connected all MOSI - MOSI, MISO-MISO, SCK-SCK, RST-RST and 5V and gnd. I get the beeping board so that sounds like it went well.
Then using your bat file (adjusted the path to conf) I get one shot to set a fuse and then it doesn't respond anymore after that. Any suggestions?

[PaulAntonDeen]

I think I need to do something with the clock speed according to (#49)?
-B 3 according to https://electronics.stackexchange.com/questions/49606/avrdude-b-3-parameter...but it doesn't work :(

[gcormier]

You can try using -B to slow it down since it's only running on the internal 8MHz oscillator. I think I used to use -B 0.5? But otherwise I have never had much luck with Zadig and/or the cheaper programmers that need it.

[PaulAntonDeen]

Turns out I could set 1 fuse and then nothing else...but that is remembered at reboot. So I just unplugged the USBasp and plugged it back in and proceeded to the second fuse, the third and finally the flash. It works now :) I ended up doing the whole thing on a rPi4 under rasbian OS and used your second script...but manually typed.

[gcormier]

Sounds about right for the inconsistent and frustrating experiences to be had with usbasp :) Glad you got it going!

[farsonic]

I'm trying to update the flash on my megadesk to provide the serial support needed for megadesk. I've tried using a buspirate as well as a usbASP to do the programing and I've soldered header pins on the the megaboard (v4) also to make this simpler. I've validated the usbASP is functional by programming using the same header into an old Arduino Mega Pro.

I've tried all combinations/variations to even set the fuses ... this is the error I'm receiving. I'm going to try another computer next.

: avrdude -u -c usbasp -p t841 -P usb -B 1500.0 -F -v -U lfuse:w:0xd6:m

avrdude.exe: Version 6.3, compiled on Feb 17 2016 at 09:25:53
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "C:\Program Files (x86)\AVRDUDESS\avrdude.conf"

         Using Port                    : usb
         Using Programmer              : usbasp
         Setting bit clk period        : 1500.0
         AVR Part                      : ATtiny841
         Chip Erase delay              : 15000 us
         PAGEL                         : P00
         BS2                           : P00
         RESET disposition             : possible i/o
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65     6     4    0 no        512    4      0  4000  4500 0xff 0xff
           flash         65    12    32    0 yes      8192   16    512  4500  4500 0xff 0xff
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00
           lock           0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00

         Programmer Type : usbasp
         Description     : USBasp, http://www.fischl.de/usbasp/

avrdude.exe: set SCK frequency to 500 Hz
avrdude.exe: warning: cannot set sck period. please check for usbasp firmware update.
avrdude.exe: error: program enable: target doesn't answer. 1
avrdude.exe: initialization failed, rc=-1
avrdude.exe: AVR device initialized and ready to accept instructions
avrdude.exe: Device signature = 0x743230
avrdude.exe: Expected signature for ATtiny841 is 1E 93 15

[farsonic]

can someone confirm the orientation of the headers for the connection for the AVR programmer...the picture on the DIY page doesn't state the orientation of the connector or which side it is interfacing from.

[farsonic]

ok, looks like a set the lfuse incorrectly and can no longer program the 841 on the megadesk. I've managed to hook up an arduino in an attempt to program it using the high voltage approach. However, can I program this while it is installed on the board? I'm having to run this arduino sketch https://www.rickety.us/2010/03/arduino-avr-high-voltage-serial-programmer/comment-page-2 and all I've done is change the lfuse settings etc. It runs and seems to get some communication with the chip but not making any changes. Here is the output...

10
Entering programming Mode

lfuse reads as EC
hfuse reads as FE
efuse reads as EE

Writing hfuse
Writing lfuse

lfuse reads as EC
hfuse reads as FE
efuse reads as EE

Anyone got any suggestions?

[gcormier]

Removing the IC is probably safest, but will require soldering skills. I'm not sure on the high voltage programming method and if it is safe to do so while it's in-circuit.

[farsonic]

Looks like I’ll be ordering another unit… Might see about ordering another tiny 841 for this one for potential recovery also.  Re Francois  19 Oct 2023 at 06:10 by ***@***.***:

…

Removing the IC is probably safest, but will require soldering skills. I'm not sure on the high voltage programming method and if it is safe to do so while it's in-circuit. — Reply to this email directly, > view it on GitHub <#101 (reply in thread)>> , or > unsubscribe <https://github.com/notifications/unsubscribe-auth/ABKKDUB67PRALQRQ3OBLKNDYAAZUHAVCNFSM5THQXQJ2U5DIOJSWCZC7NNSXTOKENFZWG5LTONUW63SDN5WW2ZLOOQ5TOMZRHE3DKNY>> . You are receiving this because you commented.> Message ID: > <gcormier/megadesk/repo-discussions/101/comments/7319657> @> github> .> com>