Home command erratic behavior: ypos changes to bad value

Hi.
I’m trying to configure a newly built Creation Station CNC router, and learn
how to use tinyG.
I get this bizarre behavior using the G28.2 homing command.
Sometimes it works exactly as described on the webpage, and sometimes it moves the Y-axis a
few inches and then changes the ypos to some totally random number and then
stops working.

That is, it reports ypos every two mm or so, and the machine moves as
expected, and then it suddenly reports a completely random number and stops.

I put an example below, and then settings in human mode and JSON.
Please let me know if there is anything that would help diagnose this. I’m
very new to tinyG and JSON.

Thanks,
Jim

————————————————-

g28.2 y0
tinyg [mm] ok>
coor:0,dist:1,stat:9
qr:32
qr:31
posy:-320.600,feed:499.00,vel:2.53
posy:-1340.000,feed:100.00,vel:0.00,coor:1,dist:0,stat:3
qr:32
posy:-52.589
posy:-54.627
posy:-56.665
posy:-56.901,vel:2.53
posy:-670.000,feed:0.00,vel:0.00,coor:1,dist:0,stat:3
qr:32
—————————————————–
$$
[fb] firmware build 440.20
[fv] firmware version 0.97
[hp] hardware platform 1.00
[hv] hardware version 8.00
[id] TinyG ID 3X2204-RUJ
[ja] junction acceleration 100000 mm
[ct] chordal tolerance 0.0100 mm
[sl] soft limit enable 0
[st] switch type 1 [0=NO,1=NC]
[mt] motor idle timeout 2.00 Sec
[ej] enable json mode 0 [0=text,1=JSON]
[jv] json verbosity 4 [0=silent,1=footer,2=messages,3=configs,4=linenum,5=verbose]
[js] json serialize style 1 [0=relaxed,1=strict]
[tv] text verbosity 1 [0=silent,1=verbose]
[qv] queue report verbosity 1 [0=off,1=single,2=triple]
[sv] status report verbosity 1 [0=off,1=filtered,2=verbose]
[si] status interval 250 ms
[ec] expand LF to CRLF on TX 0 [0=off,1=on]
[ee] enable echo 1 [0=off,1=on]
[ex] enable flow control 2 [0=off,1=XON/XOFF, 2=RTS/CTS]
[baud] USB baud rate 5 [1=9600,2=19200,3=38400,4=57600,5=115200,6=230400]
[net] network mode 0 [0=master]
[gpl] default gcode plane 0 [0=G17,1=G18,2=G19]
[gun] default gcode units mode 1 [0=G20,1=G21]
[gco] default gcode coord system 1 [1-6 (G54-G59)]
[gpa] default gcode path control 2 [0=G61,1=G61.1,2=G64]
[gdi] default gcode distance mode 0 [0=G90,1=G91]
[1ma] m1 map to axis 0 [0=X,1=Y,2=Z…]
[1sa] m1 step angle 1.800 deg
[1tr] m1 travel per revolution 4.0000 mm
[1mi] m1 microsteps 2 [1,2,4,8]
[1po] m1 polarity 0 [0=normal,1=reverse]
[1pm] m1 power management 2 [0=disabled,1=always on,2=in cycle,3=when moving]
[2ma] m2 map to axis 1 [0=X,1=Y,2=Z…]
[2sa] m2 step angle 1.800 deg
[2tr] m2 travel per revolution 4.0000 mm
[2mi] m2 microsteps 2 [1,2,4,8]
[2po] m2 polarity 0 [0=normal,1=reverse]
[2pm] m2 power management 2 [0=disabled,1=always on,2=in cycle,3=when moving]
[3ma] m3 map to axis 2 [0=X,1=Y,2=Z…]
[3sa] m3 step angle 1.800 deg
[3tr] m3 travel per revolution 4.0000 mm
[3mi] m3 microsteps 2 [1,2,4,8]
[3po] m3 polarity 1 [0=normal,1=reverse]
[3pm] m3 power management 2 [0=disabled,1=always on,2=in cycle,3=when moving]
[4ma] m4 map to axis 3 [0=X,1=Y,2=Z…]
[4sa] m4 step angle 1.800 deg
[4tr] m4 travel per revolution 4.0000 mm
[4mi] m4 microsteps 1 [1,2,4,8]
[4po] m4 polarity 0 [0=normal,1=reverse]
[4pm] m4 power management 2 [0=disabled,1=always on,2=in cycle,3=when moving]
[xam] x axis mode 1 [standard]
[xvm] x velocity maximum 2500 mm/min
[xfr] x feedrate maximum 2500 mm/min
[xtn] x travel minimum 0.000 mm
[xtm] x travel maximum 660.000 mm
[xjm] x jerk maximum 1000 mm/min^3 * 1 million
[xjh] x jerk homing 10000 mm/min^3 * 1 million
[xjd] x junction deviation 0.0500 mm (larger is faster)
[xsn] x switch min 3 [0=off,1=homing,2=limit,3=limit+homing]
[xsx] x switch max 2 [0=off,1=homing,2=limit,3=limit+homing]
[xsv] x search velocity 499 mm/min
[xlv] x latch velocity 100 mm/min
[xlb] x latch backoff 10.000 mm
[xzb] x zero backoff 5.000 mm
[yam] y axis mode 1 [standard]
[yvm] y velocity maximum 2500 mm/min
[yfr] y feedrate maximum 2500 mm/min
[ytn] y travel minimum 0.000 mm
[ytm] y travel maximum 660.000 mm
[yjm] y jerk maximum 1 mm/min^3 * 1 million
[yjh] y jerk homing 10000 mm/min^3 * 1 million
[yjd] y junction deviation 0.0500 mm (larger is faster)
[ysn] y switch min 3 [0=off,1=homing,2=limit,3=limit+homing]
[ysx] y switch max 2 [0=off,1=homing,2=limit,3=limit+homing]
[ysv] y search velocity 499 mm/min
[ylv] y latch velocity 100 mm/min
[ylb] y latch backoff 10.000 mm
[yzb] y zero backoff 5.000 mm
[zam] z axis mode 1 [standard]
[zvm] z velocity maximum 2500 mm/min
[zfr] z feedrate maximum 2500 mm/min
[ztn] z travel minimum -110.000 mm
[ztm] z travel maximum 0.000 mm
[zjm] z jerk maximum 1000 mm/min^3 * 1 million
[zjh] z jerk homing 10000 mm/min^3 * 1 million
[zjd] z junction deviation 0.0500 mm (larger is faster)
[zsn] z switch min 2 [0=off,1=homing,2=limit,3=limit+homing]
[zsx] z switch max 3 [0=off,1=homing,2=limit,3=limit+homing]
[zsv] z search velocity 200 mm/min
[zlv] z latch velocity 100 mm/min
[zlb] z latch backoff 10.000 mm
[zzb] z zero backoff 5.000 mm
[aam] a axis mode 3 [radius]
[avm] a velocity maximum 230400 deg/min
[afr] a feedrate maximum 230400 deg/min
[atn] a travel minimum -1.000 deg
[atm] a travel maximum -1.000 deg
[ajm] a jerk maximum 5760 deg/min^3 * 1 million
[ajh] a jerk homing 11520 deg/min^3 * 1 million
[ajd] a junction deviation 0.0500 deg (larger is faster)
[ara] a radius value 0.1989 deg
[asn] a switch min 0 [0=off,1=homing,2=limit,3=limit+homing]
[asx] a switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
[asv] a search velocity 600 deg/min
[alv] a latch velocity 100 deg/min
[alb] a latch backoff 5.000 deg
[azb] a zero backoff 2.000 deg
[bam] b axis mode 0 [disabled]
[bvm] b velocity maximum 3600 deg/min
[bfr] b feedrate maximum 3600 deg/min
[btn] b travel minimum -1.000 deg
[btm] b travel maximum -1.000 deg
[bjm] b jerk maximum 20 deg/min^3 * 1 million
[bjd] b junction deviation 0.0500 deg (larger is faster)
[bra] b radius value 1.0000 deg
[cam] c axis mode 0 [disabled]
[cvm] c velocity maximum 3600 deg/min
[cfr] c feedrate maximum 3600 deg/min
[ctn] c travel minimum -1.000 deg
[ctm] c travel maximum -1.000 deg
[cjm] c jerk maximum 20 deg/min^3 * 1 million
[cjd] c junction deviation 0.0500 deg (larger is faster)
[cra] c radius value 1.0000 deg
[p1frq] pwm frequency 100 Hz
[p1csl] pwm cw speed lo 1000 RPM
[p1csh] pwm cw speed hi 2000 RPM
[p1cpl] pwm cw phase lo 0.125 [0..1]
[p1cph] pwm cw phase hi 0.200 [0..1]
[p1wsl] pwm ccw speed lo 1000 RPM
[p1wsh] pwm ccw speed hi 2000 RPM
[p1wpl] pwm ccw phase lo 0.125 [0..1]
[p1wph] pwm ccw phase hi 0.200 [0..1]
[p1pof] pwm phase off 0.100 [0..1]
[g54x] g54 x offset 0.000 mm
[g54y] g54 y offset 0.000 mm
[g54z] g54 z offset 0.000 mm
[g54a] g54 a offset 0.000 deg
[g54b] g54 b offset 0.000 deg
[g54c] g54 c offset 0.000 deg
[g55x] g55 x offset 75.000 mm
[g55y] g55 y offset 75.000 mm
[g55z] g55 z offset 0.000 mm
[g55a] g55 a offset 0.000 deg
[g55b] g55 b offset 0.000 deg
[g55c] g55 c offset 0.000 deg
[g56x] g56 x offset 0.000 mm
[g56y] g56 y offset 0.000 mm
[g56z] g56 z offset 0.000 mm
[g56a] g56 a offset 0.000 deg
[g56b] g56 b offset 0.000 deg
[g56c] g56 c offset 0.000 deg
[g57x] g57 x offset 0.000 mm
[g57y] g57 y offset 0.000 mm
[g57z] g57 z offset 0.000 mm
[g57a] g57 a offset 0.000 deg
[g57b] g57 b offset 0.000 deg
[g57c] g57 c offset 0.000 deg
[g58x] g58 x offset 0.000 mm
[g58y] g58 y offset 0.000 mm
[g58z] g58 z offset 0.000 mm
[g58a] g58 a offset 0.000 deg
[g58b] g58 b offset 0.000 deg
[g58c] g58 c offset 0.000 deg
[g59x] g59 x offset 0.000 mm
[g59y] g59 y offset 0.000 mm
[g59z] g59 z offset 0.000 mm
[g59a] g59 a offset 0.000 deg
[g59b] g59 b offset 0.000 deg
[g59c] g59 c offset 0.000 deg
[g92x] g92 x offset 0.000 mm
[g92y] g92 y offset 0.000 mm
[g92z] g92 z offset 0.000 mm
[g92a] g92 a offset 0.000 deg
[g92b] g92 b offset 0.000 deg
[g92c] g92 c offset 0.000 deg
[g28x] g28 x position 0.000 mm
[g28y] g28 y position 0.000 mm
[g28z] g28 z position 0.000 mm
[g28a] g28 a position 0.000 deg
[g28b] g28 b position 0.000 deg
[g28c] g28 c position 0.000 deg
[g30x] g30 x position 0.000 mm
[g30y] g30 y position 0.000 mm
[g30z] g30 z position 0.000 mm
[g30a] g30 a position 0.000 deg
[g30b] g30 b position 0.000 deg
[g30c] g30 c position 0.000 deg
tinyg [mm] ok>
{“1”:n}
{“r”:{“1”:{“ma”:0,”sa”:1.800,”tr”:4.0000,”mi”:2,”po”:0,”pm”:2}},”f”:[1,0,8,2230]}
{“2”:n}
{“r”:{“2”:{“ma”:1,”sa”:1.800,”tr”:4.0000,”mi”:2,”po”:0,”pm”:2}},”f”:[1,0,8,9202]}
{“3”:n}
{“r”:{“3”:{“ma”:2,”sa”:1.800,”tr”:4.0000,”mi”:2,”po”:1,”pm”:2}},”f”:[1,0,8,1390]}
{“4”:n}
{“r”:{“4”:{“ma”:3,”sa”:1.800,”tr”:4.0000,”mi”:1,”po”:0,”pm”:2}},”f”:[1,0,8,8333]}
{“x”:n}
{“r”:{“x”:{“am”:1,”vm”:2500,”fr”:2500,”tn”:0.000,”tm”:660.000,”jm”:1000,”jh”:10000,”jd”:0.0500,”sn”:3,”sx”:2,”sv”:499,”lv”:100,”lb”:10.000,”zb”:5.000}},”f”:[1,0,8,2166]}
{“y”:n}
{“r”:{“y”:{“am”:1,”vm”:2500,”fr”:2500,”tn”:0.000,”tm”:660.000,”jm”:1,”jh”:10000,”jd”:0.0500,”sn”:3,”sx”:2,”sv”:499,”lv”:100,”lb”:10.000,”zb”:5.000}},”f”:[1,0,8,5751]}
{“z”:n}
{“r”:{“z”:{“am”:1,”vm”:2500,”fr”:2500,”tn”:-110.000,”tm”:0.000,”jm”:1000,”jh”:10000,”jd”:0.0500,”sn”:2,”sx”:3,”sv”:200,”lv”:100,”lb”:10.000,”zb”:5.000}},”f”:[1,0,8,9643]}
{“sys”:n}
{“r”:{“sys”:{“fb”:440.20,”fv”:0.970,”hp”:1,”hv”:8,”id”:”3X2204-RUJ”,”ja”:100000,”ct”:0.0100,”sl”:0,”st”:1,”mt”:2.00,”ej”:1,”jv”:4,”js”:1,”tv”:1,”qv”:1,”sv”:1,”si”:250,”ec”:0,”ee”:1,”ex”:2,”baud”:5,”net”:0,”gpl”:0,”gun”:1,”gco”:1,”gpa”:2,”gdi”:0}},”f”:[1,0,10,8775]}
{“hom”:n}
{“r”:{“hom”:{“e”:0,”x”:0,”y”:0,”z”:0,”a”:0,”b”:0,”c”:0}},”f”:[1,0,10,2154]}