chmr

Hi Eric,
the ISP connector is only for flashing firmware and debugging with a special ISP adapter like the Atmel-ICE. You can’t use it to send Gcode commands to tinyg.

However, on the tinyg V8 board you can use J14 to access the serial port that is also used by the USB connection. Connecting this to the Espruino should be straight-forward (very much like wiring up the bluetooth adapter to the Espruino). When the Espruino sends Gcode commands to the serial port, tinyg will execute them normally.

Note that you can’t use tinyg’s USB and serial ports at the same time, as both of them use the same physical processor pins.

Hi, hard to tell what’s wrong from your description, but here are some suggestions:

– Update the firmware for tinyg if you are running anything older than 435.10 ($fb). Also need to upgrade to the newest tgfx, and re-adjust the parameters.

– Make sure flow control is set to RTS/CTS ($ex=2), also set this on the host program (I think tgfx does this automatically).

– Check the mechanical side: Belt tensions, pulley set screws; for Z, make sure the threaded rod runs smooth on the whole range.

– Motor setup: Adjust the motor current as described in the wiki, and try manual movement commands on every axis: G0Z20 should move Z axis up 20mm, G0Z0 move it back to the 0 position. “Plunging too far into the board” is often caused by wrong speed parameters: The z axis would move down with a slow feedrate, but when it should move up again, it can’t because the configured speed is set too high and the motor can’t follow. The next downward move will go into the wasteboard.
First, set the speed settings to slow: $xvm=1000, $yvm=1000, $zvm=200, and same with acceleration (jerk) settings: $xjm=20, $yjm=20, $zjm=50. If the shapeoko runs fine with those, gradually increase the speed. I think the default shapeoko settings are a bit too optimistic.

gagandeep,
tinyg’s $xtr setting works differently than in grbl: In grbl, you configure (micro)steps per mm; tinyg wants mm per motor revolution. For the Ox, the thoretical value is 60 (60 teeth on the pulley * 3mm per tootn on belt). If you had $0=26.772 on grbl, on tinyg $1tr shoul be = 200 steps per revolution (1.8 deg motor) * 8 microsteps / 26.772 steps per mm = 59.764 mm per revolution. Seems pretty close to the theoretical value.

contacttodd,
calculation for your machine is the same: $1tr = number of teeth on pulley * distance of teeth on the belt. I just don’t know the actual values for your plotter.

First amend the $Xsa (step angle, 1.8 for both) and $Xtr settings, then you can adjust the speed ($Xvm and $Xfr).

Gwandad, good to hear you have some progress.
I’d like to clear up some confusion: Tinyg and GRBL are two different controllers offering the same functionality (with only a few differences). You have either tinyg or grbl, not both at the same time.

Tinyg is a copntroller board + firmware.
GRBL is a Arduino controller board + grblshield (motor driver) + firmware.

“Universal Gcode sender” is not so universal after all, it only works with grbl, not with tinyg (speaking of the official version here, other people have ported it to tinyg).
“GRBL controller” is a very misleading name for a software that sends Gcode to GRBL and only works with GRBL.

To speak with Tinyg, you need other software:
Tgfx, which you already have,
Chilipeppr works within a browser window and has some nice features like a real preview of the Gcode,
jCNC also works nicely with preview (german website).

Coolterm is a very basic and simple tool, useful when you want to get directly to the tinyg hardware/firmware and want to exclude the influence of any other software. If it does not work, check the connection settings for baud rate and flow control (if tinyg is set to $ex=1, use XON in Coolterm; if $ex=2, use CTS in Coolterm).

And you can only have one piece of software talking to tinyg at any one time, so you have to disconnect/terminate tgfx before connecting with Coolterm for example.

I think this was (part of) the fix for the clunking noises: If a movement is too short to execute in a controlled manner, don’t do it. I consider that OK as long as the physical position is remembered and the move is not forgotten (i.e. no drift between logical and physical position at the end of a cycle).
But I agree that 0.8mm is a very high value, on my machine a full step is 0.12mm and a microstep 0.015mm . I have found no direct influence of max speed or jerk to that value, like it was before.

I consider the other problems much more critical.

I tried the new firmware version 435.06, and at first it looked much better. When trying simple G0 moves like above, I found the following:

(machine freshly reset and at 0/0/0)
G0 X0.8 (X motor does not move at all, ? shows X=0.8)
G0 X1 (X motor moves for 1mm, ? shows X=1.0)
G0 X0 (X motor moves back to 0, so far OK).

G0 X0.8 (motor does not move, like above)
G1 Z-1 F100 (Z axis moves down, but X axis moves as well. Goodbye drill bit)
(X is now physically and logically at 0.8)

• This reply was modified 10 years, 4 months ago by chmr.
• This reply was modified 10 years, 4 months ago by chmr. Reason: I hate this bbp forum software

Hi,
if the board is a bit older than a year, it may not have the bootloader installed (see https://github.com/synthetos/TinyG/wiki/TinyG-Boot-Loader for details).
Am also interested in the answers to the questions in the previous post.

And another short video, featuring the hammer-sound with $xvm=9600 $xjm=80. First, a moves to 1mm and back are done ok. Then, a move to 0.7mm and back produces the clunk.
Video

In this case, the actual travel was accurate. But this is not always the case, I have seen it also miss steps, or even jump in the wrong direction.

• This reply was modified 10 years, 5 months ago by chmr.