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This evening I dared to hit the “upload” button after compiling Geeetech’s firmware. I was immediately faced with a huge number of timeouts and other errors that all looked quite horrible, but somewhat reminiscent of a baud rate mismatch.

Enabling verbose mode for the upload showed avrdude being given a speed of 115,200 for uploading the firmware image. A bit of a hunt on the Internet suggested that the actual speed for uploading to my printer should be 57,600, but there’s no obvious place to set the comms rate for the serial device (/dev/ttyUSB0 in my case).

Further hunting revealed that the speed is set in the support files for the Sanguino board I’ve posted about downloading already. In my case I needed to edit $HOME/.arduino15/packages/Sanguino/hardware/avr/1.0.2/boards.txt and change the line that reads

sanguino.menu.cpu.atmega1284p.upload.speed=115200

to

sanguino.menu.cpu.atmega1284p.upload.speed=57600

Restarting the IDE and hitting upload once again resulted in a clean compile and upload to the printer which subsequently restarted itself quite happily.

Now time to do some calibration, I think.

As I have posted previously, trying to compile the Geeetech Sanguino firmware with a recent version of the Arduino IDE results in the following errors:

In file included from sketch/SdFile.h:27:0,
                 from sketch/cardreader.h:8,
                 from sketch/Marlin_main.cpp:44:
SdBaseFile.h:38: error: using typedef-name 'fpos_t' after 'struct'
 struct fpos_t {
        ^
In file included from sketch/Marlin.h:10:0,
                 from sketch/Marlin_main.cpp:30:
/usr/local/arduino-1.8.5/hardware/tools/avr/avr/include/stdio.h:950:33:
note: 'fpos_t' has a previous declaration here
 __extension__ typedef long long fpos_t;
                                 ^
exit status 1
using typedef-name 'fpos_t' after 'struct'

The recommendation repeated often on the Geeetech forums is to use v1.0.1 of the IDE because the code is written specifically for that version, but that’s hardly practical and a little misleading, I’d suggest. It’s more the case that the code happens to compile with that version of the IDE and won’t with later ones because of the above error which is presumably due to changes within the compilation environment.

In fact, the problem is relatively easy to fix by changing the name of the variable in the firmware source code. It’s only used in two files, SdBaseFile.cpp and SdBaseFile.h, so they’re easy enough to edit by hand changing all the occurrences of “fpos_t” to something else. Because I couldn’t be bothered to edit them, I changed to the firmware source directory and ran the following to change “fpos_t” to “gt_fpos_t”:

sed -i.bak -e 's/fpos_t/gt_fpos_t/g' SdBaseFile.cpp SdBaseFile.h

That done, recompiling gives the result:

Archiving built core (caching) in: /tmp/arduino_cache_531416
/core/core_Sanguino_avr_sanguino_cpu_atmega1284p_9d0b33a4df3327bd721e7d4e4de1171e.a
Sketch uses 92644 bytes (71%) of program storage space. Maximum is 130048 bytes.
Global variables use 4029 bytes (24%) of dynamic memory, leaving 12355 bytes for local
variables. Maximum is 16384 bytes.

Happy days. Next comes the scary step of seeing if I can upload it successfully.

Before I start work tuning my Geeetech Prusa i3 clone I thought I’d best get to the point where I can rebuild the firmware supplied by Geeetech. Their firmware appears to be based on an early version of the Marlin firmware and whilst I’d like to upgrade to the latest release in the fullness of time, getting the original to work first seems like a good plan.

I ran into an immediate problem with the 1.0.5 version of the Arduino IDE in the Mint19 and Ubuntu 18.04 repositories because it doesn’t allow me to set the Sanguino board type before I compile the code. There appears to be no fix for this but to download the latest version from the Arduino website (I have v1.8.5) and install it according to their instructions. Unfortunately it’s not quite that easy. Even the 1.8.5 version doesn’t know about the Sanguino, but unlike 1.0.5 it allows us to add some board definitions from external URLs.

After starting the IDE the first thing to do is to go to File->Preferences and near the bottom of the Settings tab there’s a box labelled “Additional Boards Manager URLs”. Into that paste https://raw.githubusercontent.com/Lauszus/Sanguino/master/package_lauszus_sanguino_index.json and click “Ok”.

Next go to Tools->Board->Boards Manager... and in the search box it should be enough to enter “sang” to find the right one: “Sanguino by Kristian Sloth Lauszus”. Clicking on “More info” brings up an “Install” button. Do the obvious 🙂 If like me you have a piece of damp string for an Internet connection, you may want to go and make yourself a drink at this point. It can take a while.

Once installed, close the window and go back to the Tools->Board menu. Sanguino should now be selectable right at the bottom of the list. After that the processor must be selected from Tools->Processor. My aluminium printer model has a 16Mhz 1284P so obviously that’s the one I chose.

Unfortunately my problems did not end there. Selecting an arduino project to open, I navigated to the firmware directory and opened Prusa_I3_A.ino. Attempting to compile the firmware throws the following errors:

Build options changed, rebuilding all
In file included from sketch/SdFile.h:27:0,
                 from sketch/cardreader.h:8,
                 from sketch/Marlin_main.cpp:44:
SdBaseFile.h:38: error: using typedef-name 'fpos_t' after 'struct'
 struct fpos_t {
        ^
In file included from sketch/Marlin.h:10:0,
                 from sketch/Marlin_main.cpp:30:
/usr/local/arduino-1.8.5/hardware/tools/avr/avr/include/stdio.h:950:33:
note: 'fpos_t' has a previous declaration here
 __extension__ typedef long long fpos_t;
                                 ^
exit status 1
using typedef-name 'fpos_t' after 'struct'

which looks like some of the firmware files use a variable name that clashes with a system name. More of that in another post.