diff --git a/data/ublox_ppk.conf b/data/ublox_ppk.conf
new file mode 100644
index 0000000000000000000000000000000000000000..3b51f924184fdb176d23424a05810731ecb1cc88
--- /dev/null
+++ b/data/ublox_ppk.conf
@@ -0,0 +1,84 @@
+# RTKLIB-Demo5:  Configuration options for a post processed solution for two u-blox receivers
+
+# Most common options
+
+pos1-posmode       =kinematic  # solution mode (single, dgps, kinematic, static, movingbase)
+pos1-soltype       =combined   # solution type (forward, backward, combined)
+pos1-frequency     =l1         # (l1, l1+l2, l1+l2+l5)
+pos1-elmask        =15         # min sat elevation to include in solution (deg)
+pos1-snrmask_r     =off        # SNR mask rover (off, on)
+pos1-snrmask_b     =off        # SNR mask base (off, on)
+pos1-snrmask_L1    =0,0,0,0,0,0,0,0,0 # SNR masks for different elevations
+pos1-snrmask_L2    =0,0,0,0,0,0,0,0,0 # SNR masks for different elevations
+pos1-dynamics      =on         # add dynamic states to kalman filter (off, on)
+pos1-exclsats      =           # sats excluded from solution (prns eg: G03 E12)
+pos1-navsys        =15         # (1:gps+2:sbas+4:glo+8:gal+16:qzs+32:comp)
+
+pos2-armode        =fix-and-hold # Ambiguity resolution (AR) mode (off, continuous, instantaneous, fix-and-hold)
+pos2-gloarmode     =on         # Glonass AR mode (off, on, fix-and-hold, autocal)
+pos2-bdsarmode     =off        # Bediou AR mode (off, on)
+pos2-aroutcnt      =50         # outage count to reset sat ambiguity (samples)
+pos2-arminfix      =50         # min # of fix samples to enable AR hold (samples)
+pos2-rejionno      =1.0        # phase bias outlier threshold (m)
+pos2-maxage        =30         # max age of differential (secs)
+
+out-solformat      =enu        # solution format (llh, xyz, enu, nmea)
+out-outstat        =off        # output statistics (off, state, residual)
+out-height         =ellipsoidal # height reference (ellipsoidal, geodetic)
+
+ant2-postype       =rinexhead  # base location source (llh, xyz, single, posfile, rinexhead, rtcm, raw)
+ant2-pos1          =0          # base antenna location 1 (deg|m)
+ant2-pos2          =0          # base antenna location 2 (deg|m)
+ant2-pos3          =0          # base antenna location 3 (m|m)
+ant2-anttype       =           # * = use antenna type in rinex header
+
+ 
+# Less frequently used options
+
+pos2-arthres       =3.0        # minimum AR ratio for fix (m)
+pos2-arthres1      =0.1        # max variance of position states to attempt AR (m)
+pos2-varholdamb    =0.1        # variance of fix-and-hold tracking feedback (cyc^2)
+pos2-arlockcnt     =0          # fixed hold off for adding new/re-locked sats to AR (samples)
+pos2-minfixsats    =4          # min sats required for fix
+pos2-minholdsats   =5          # min sats required for AR hold
+pos2-mindropsats   =10         # min sats required to drop sats from AR
+pos2-arelmask      =15         # min sat elevation to include in AR (deg)
+pos2-elmaskhold    =15         # min sat elevation to include in AR hold (deg)
+pos2-rejgdop       =30         # GDOP threshold (m)
+pos2-niter         =1          # number of iterations in measurement update
+pos2-baselen       =0          # baseline length(0:disable,m)
+pos2-basesig       =0          # baseline length sigma (m)
+
+out-outhead        =on         # output header (off, on)
+out-outopt         =on         # output solution options (off, on)
+out-timesys        =gpst       # time system (gpst, utc, jst)
+out-timeform       =hms        # time format (tow, hms)
+out-timendec       =3          # number of decimals in time output
+out-degform        =deg        # degree ouput format (deg, dms)
+out-fieldsep       =           # output field separator
+out-maxsolstd      =0          # max sigma of solution output (0:all, m)
+out-geoid          =internal   # (internal, egm96, egm08_2.5, egm08_1, gsi2000)
+
+stats-eratio1      =300        # ratio of input stdev of code to phase observations
+stats-eratio2      =300        # ratio of input stdev of code to phase observations
+stats-errphase     =0.003      # base term of carrier-phase input stdev (m)
+stats-errphaseel   =0.003      # elevation term of carrier-phase input stdev (m)
+stats-errphasebl   =0          # baseline term of carrier-phase input stdev (m/10km)
+stats-stdbias      =30         # initial stdev for carrier-phase biases (m)
+stats-prnaccelh    =3          # stdev of horiz process noise for rover acc (m/s^2)
+stats-prnaccelv    =1          # stdev of vert process noise for rover acc (m/s^2)
+stats-prnbias      =0.0001     # stdev of carrier-phase process noise(m)
+stats-clkstab      =5e-12      # satellite clock stability (s/s)
+
+ant2-antdele       =0          # (m)
+ant2-antdeln       =0          # (m)
+ant2-antdelu       =0          # (m)
+ant2-maxaveep      =1          # epochs to use to detrmine base position
+ant2-initrst       =on         # initialize base position on restart (off, on)
+
+misc-timeinterp    =on        # interpolate base position in post-processing (off, on)
+
+
+# For information on how to find all available configuration file options, see:
+#      https://rtklibexplorer.wordpress.com/2019/03/17/rtklib-documentation-tips/
+
diff --git a/src/rtklib.h b/src/rtklib.h
index 2c6a4a007a08c89454e0e4943eb83fd5e330105b..c64411c294e0b8c4e0970daed72aa04a6f2d763b 100644
--- a/src/rtklib.h
+++ b/src/rtklib.h
@@ -58,7 +58,7 @@ extern "C" {
 
 #define VER_RTKLIB  "demo5"             /* library version */
 
-#define PATCH_LEVEL "b33b2"               /* patch level */
+#define PATCH_LEVEL "b33c"               /* patch level */
 
 #define COPYRIGHT_RTKLIB \
             "Copyright (C) 2007-2019 T.Takasu\nAll rights reserved."