An I/O controller for virtual pinball machines: accelerometer nudge sensing, analog plunger input, button input encoding, LedWiz compatible output controls, and more.

Dependencies:   mbed FastIO FastPWM USBDevice

Fork of Pinscape_Controller by Mike R


This is Version 2 of the Pinscape Controller, an I/O controller for virtual pinball machines. (You can find the old version 1 software here.) Pinscape is software for the KL25Z that turns the board into a full-featured I/O controller for virtual pinball, with support for accelerometer-based nudging, a real plunger, button inputs, and feedback device control.

In case you haven't heard of the concept before, a "virtual pinball machine" is basically a video pinball simulator that's built into a real pinball machine body. A TV monitor goes in place of the pinball playfield, and a second TV goes in the backbox to serve as the "backglass" display. A third smaller monitor can serve as the "DMD" (the Dot Matrix Display used for scoring on newer machines), or you can even install a real pinball plasma DMD. A computer is hidden inside the cabinet, running pinball emulation software that displays a life-sized playfield on the main TV. The cabinet has all of the usual buttons, too, so it not only looks like the real thing, but plays like it too. That's a picture of my own machine to the right. On the outside, it's built exactly like a real arcade pinball machine, with the same overall dimensions and all of the standard pinball cabinet hardware.

A few small companies build and sell complete, finished virtual pinball machines, but I think it's more fun as a DIY project. If you have some basic wood-working skills and know your way around PCs, you can build one from scratch. The computer part is just an ordinary Windows PC, and all of the pinball emulation can be built out of free, open-source software. In that spirit, the Pinscape Controller is an open-source software/hardware project that offers a no-compromises, all-in-one control center for all of the unique input/output needs of a virtual pinball cabinet. If you've been thinking about building one of these, but you're not sure how to connect a plunger, flipper buttons, lights, nudge sensor, and whatever else you can think of, this project might be just what you're looking for.

You can find much more information about DIY Pin Cab building in general in the Virtual Cabinet Forum on Also visit my Pinscape Resources page for more about this project and other virtual pinball projects I'm working on.


  • Pinscape Release Builds: This page has download links for all of the Pinscape software. To get started, install and run the Pinscape Config Tool on your Windows computer. It will lead you through the steps for installing the Pinscape firmware on the KL25Z.
  • Config Tool Source Code. The complete C# source code for the config tool. You don't need this to run the tool, but it's available if you want to customize anything or see how it works inside.


The new Version 2 Build Guide is now complete! This new version aims to be a complete guide to building a virtual pinball machine, including not only the Pinscape elements but all of the basics, from sourcing parts to building all of the hardware.

You can also refer to the original Hardware Build Guide (PDF), but that's out of date now, since it refers to the old version 1 software, which was rather different (especially when it comes to configuration).

System Requirements

The new config tool requires a fairly up-to-date Microsoft .NET installation. If you use Windows Update to keep your system current, you should be fine. A modern version of Internet Explorer (IE) is required, even if you don't use it as your main browser, because the config tool uses some system components that Microsoft packages into the IE install set. I test with IE11, so that's known to work. IE8 doesn't work. IE9 and 10 are unknown at this point.

The Windows requirements are only for the config tool. The firmware doesn't care about anything on the Windows side, so if you can make do without the config tool, you can use almost any Windows setup.

Main Features

Plunger: The Pinscape Controller started out as a "mechanical plunger" controller: a device for attaching a real pinball plunger to the video game software so that you could launch the ball the natural way. This is still, of course, a central feature of the project. The software supports several types of sensors: a high-resolution optical sensor (which works by essentially taking pictures of the plunger as it moves); a slide potentionmeter (which determines the position via the changing electrical resistance in the pot); a quadrature sensor (which counts bars printed on a special guide rail that it moves along); and an IR distance sensor (which determines the position by sending pulses of light at the plunger and measuring the round-trip travel time). The Build Guide explains how to set up each type of sensor.

Nudging: The KL25Z (the little microcontroller that the software runs on) has a built-in accelerometer. The Pinscape software uses it to sense when you nudge the cabinet, and feeds the acceleration data to the pinball software on the PC. This turns physical nudges into virtual English on the ball. The accelerometer is quite sensitive and accurate, so we can measure the difference between little bumps and hard shoves, and everything in between. The result is natural and immersive.

Buttons: You can wire real pinball buttons to the KL25Z, and the software will translate the buttons into PC input. You have the option to map each button to a keyboard key or joystick button. You can wire up your flipper buttons, Magna Save buttons, Start button, coin slots, operator buttons, and whatever else you need.

Feedback devices: You can also attach "feedback devices" to the KL25Z. Feedback devices are things that create tactile, sound, and lighting effects in sync with the game action. The most popular PC pinball emulators know how to address a wide variety of these devices, and know how to match them to on-screen action in each virtual table. You just need an I/O controller that translates commands from the PC into electrical signals that turn the devices on and off. The Pinscape Controller can do that for you.

Expansion Boards

There are two main ways to run the Pinscape Controller: standalone, or using the "expansion boards".

In the basic standalone setup, you just need the KL25Z, plus whatever buttons, sensors, and feedback devices you want to attach to it. This mode lets you take advantage of everything the software can do, but for some features, you'll have to build some ad hoc external circuitry to interface external devices with the KL25Z. The Build Guide has detailed plans for exactly what you need to build.

The other option is the Pinscape Expansion Boards. The expansion boards are a companion project, which is also totally free and open-source, that provides Printed Circuit Board (PCB) layouts that are designed specifically to work with the Pinscape software. The PCB designs are in the widely used EAGLE format, which many PCB manufacturers can turn directly into physical boards for you. The expansion boards organize all of the external connections more neatly than on the standalone KL25Z, and they add all of the interface circuitry needed for all of the advanced software functions. The big thing they bring to the table is lots of high-power outputs. The boards provide a modular system that lets you add boards to add more outputs. If you opt for the basic core setup, you'll have enough outputs for all of the toys in a really well-equipped cabinet. If your ambitions go beyond merely well-equipped and run to the ridiculously extravagant, just add an extra board or two. The modular design also means that you can add to the system over time.

Expansion Board project page

Update notes

If you have a Pinscape V1 setup already installed, you should be able to switch to the new version pretty seamlessly. There are just a couple of things to be aware of.

First, the "configuration" procedure is completely different in the new version. Way better and way easier, but it's not what you're used to from V1. In V1, you had to edit the project source code and compile your own custom version of the program. No more! With V2, you simply install the standard, pre-compiled .bin file, and select options using the Pinscape Config Tool on Windows.

Second, if you're using the TSL1410R optical sensor for your plunger, there's a chance you'll need to boost your light source's brightness a little bit. The "shutter speed" is faster in this version, which means that it doesn't spend as much time collecting light per frame as before. The software actually does "auto exposure" adaptation on every frame, so the increased shutter speed really shouldn't bother it, but it does require a certain minimum level of contrast, which requires a certain minimal level of lighting. Check the plunger viewer in the setup tool if you have any problems; if the image looks totally dark, try increasing the light level to see if that helps.

New Features

V2 has numerous new features. Here are some of the highlights...

Dynamic configuration: as explained above, configuration is now handled through the Config Tool on Windows. It's no longer necessary to edit the source code or compile your own modified binary.

Improved plunger sensing: the software now reads the TSL1410R optical sensor about 15x faster than it did before. This allows reading the sensor at full resolution (400dpi), about 400 times per second. The faster frame rate makes a big difference in how accurately we can read the plunger position during the fast motion of a release, which allows for more precise position sensing and faster response. The differences aren't dramatic, since the sensing was already pretty good even with the slower V1 scan rate, but you might notice a little better precision in tricky skill shots.

Keyboard keys: button inputs can now be mapped to keyboard keys. The joystick button option is still available as well, of course. Keyboard keys have the advantage of being closer to universal for PC pinball software: some pinball software can be set up to take joystick input, but nearly all PC pinball emulators can take keyboard input, and nearly all of them use the same key mappings.

Local shift button: one physical button can be designed as the local shift button. This works like a Shift button on a keyboard, but with cabinet buttons. It allows each physical button on the cabinet to have two PC keys assigned, one normal and one shifted. Hold down the local shift button, then press another key, and the other key's shifted key mapping is sent to the PC. The shift button can have a regular key mapping of its own as well, so it can do double duty. The shift feature lets you access more functions without cluttering your cabinet with extra buttons. It's especially nice for less frequently used functions like adjusting the volume or activating night mode.

Night mode: the output controller has a new "night mode" option, which lets you turn off all of your noisy devices with a single button, switch, or PC command. You can designate individual ports as noisy or not. Night mode only disables the noisemakers, so you still get the benefit of your flashers, button lights, and other quiet devices. This lets you play late into the night without disturbing your housemates or neighbors.

Gamma correction: you can designate individual output ports for gamma correction. This adjusts the intensity level of an output to make it match the way the human eye perceives brightness, so that fades and color mixes look more natural in lighting devices. You can apply this to individual ports, so that it only affects ports that actually have lights of some kind attached.

IR Remote Control: the controller software can transmit and/or receive IR remote control commands if you attach appropriate parts (an IR LED to send, an IR sensor chip to receive). This can be used to turn on your TV(s) when the system powers on, if they don't turn on automatically, and for any other functions you can think of requiring IR send/receive capabilities. You can assign IR commands to cabinet buttons, so that pressing a button on your cabinet sends a remote control command from the attached IR LED, and you can have the controller generate virtual key presses on your PC in response to received IR commands. If you have the IR sensor attached, the system can use it to learn commands from your existing remotes.

Yet more USB fixes: I've been gradually finding and fixing USB bugs in the mbed library for months now. This version has all of the fixes of the last couple of releases, of course, plus some new ones. It also has a new "last resort" feature, since there always seems to be "just one more" USB bug. The last resort is that you can tell the device to automatically reboot itself if it loses the USB connection and can't restore it within a given time limit.

More Downloads

  • Custom VP builds: I created modified versions of Visual Pinball 9.9 and Physmod5 that you might want to use in combination with this controller. The modified versions have special handling for plunger calibration specific to the Pinscape Controller, as well as some enhancements to the nudge physics. If you're not using the plunger, you might still want it for the nudge improvements. The modified version also works with any other input controller, so you can get the enhanced nudging effects even if you're using a different plunger/nudge kit. The big change in the modified versions is a "filter" for accelerometer input that's designed to make the response to cabinet nudges more realistic. It also makes the response more subdued than in the standard VP, so it's not to everyone's taste. The downloads include both the updated executables and the source code changes, in case you want to merge the changes into your own custom version(s).

    Note! These features are now standard in the official VP releases, so you don't need my custom builds if you're using 9.9.1 or later and/or VP 10. I don't think there's any reason to use my versions instead of the latest official ones, and in fact I'd encourage you to use the official releases since they're more up to date, but I'm leaving my builds available just in case. In the official versions, look for the checkbox "Enable Nudge Filter" in the Keys preferences dialog. My custom versions don't include that checkbox; they just enable the filter unconditionally.
  • Output circuit shopping list: This is a saved shopping cart at with the parts needed to build one copy of the high-power output circuit for the LedWiz emulator feature, for use with the standalone KL25Z (that is, without the expansion boards). The quantities in the cart are for one output channel, so if you want N outputs, simply multiply the quantities by the N, with one exception: you only need one ULN2803 transistor array chip for each eight output circuits. If you're using the expansion boards, you won't need any of this, since the boards provide their own high-power outputs.
  • Cary Owens' optical sensor housing: A 3D-printable design for a housing/mounting bracket for the optical plunger sensor, designed by Cary Owens. This makes it easy to mount the sensor.
  • Lemming77's potentiometer mounting bracket and shooter rod connecter: Sketchup designs for 3D-printable parts for mounting a slide potentiometer as the plunger sensor. These were designed for a particular slide potentiometer that used to be available from an seller but is no longer listed. You can probably use this design as a starting point for other similar devices; just check the dimensions before committing the design to plastic.

Copyright and License

The Pinscape firmware is copyright 2014, 2021 by Michael J Roberts. It's released under an MIT open-source license. See License.

Warning to VirtuaPin Kit Owners

This software isn't designed as a replacement for the VirtuaPin plunger kit's firmware. If you bought the VirtuaPin kit, I recommend that you don't install this software. The VirtuaPin kit uses the same KL25Z microcontroller that Pinscape uses, but the rest of its hardware is different and incompatible. In particular, the Pinscape firmware doesn't include support for the IR proximity sensor used in the VirtuaPin plunger kit, so you won't be able to use your plunger device with the Pinscape firmware. In addition, the VirtuaPin setup uses a different set of GPIO pins for the button inputs from the Pinscape defaults, so if you do install the Pinscape firmware, you'll have to go into the Config Tool and reassign all of the buttons to match the VirtuaPin wiring.

--- a/main.cpp	Thu Apr 13 23:27:59 2017 +0000
+++ b/main.cpp	Fri Apr 14 17:56:54 2017 +0000
@@ -4082,17 +4082,19 @@
 NVM nvm;
-// Flag: configuration save requested.  The USB command message handler
-// sets this flag when a command is sent requesting the save.  We don't
-// do the save inline in the command handler, but handle it on the next 
-// main loop iteration.
-const uint8_t SAVE_CONFIG_ONLY = 1;
-const uint8_t SAVE_CONFIG_AND_REBOOT = 2;
-uint8_t saveConfigPending = 0;
-// If saveConfigPending == SAVE_CONFIG_AND_REBOOT, this specifies the
-// delay time in seconds before rebooting.
-uint8_t saveConfigRebootTime;
+// Configuration save state
+const uint8_t SAVE_CONFIG_IDLE = 0;         // no config save work pending
+const uint8_t SAVE_CONFIG_ONLY = 1;         // save is pending
+const uint8_t SAVE_CONFIG_AND_REBOOT = 2;   // save is pending, reboot after save
+const uint8_t SAVE_CONFIG_REBOOT = 3;       // save done, reboot is pending
+uint8_t saveConfigState = SAVE_CONFIG_IDLE;
+// Save Config post-processing time, in seconds.
+// If saveConfigState == SAVE_CONFIG_AND_REBOOT, we reboot after this
+// time elapses.  Otherwise, we simply clear the timer and clear the
+// "succeeded" flag.
+uint8_t saveConfigPostTime;
 // status flag for successful config save - set to 0x40 on success
 uint8_t saveConfigSucceededFlag;
@@ -4437,8 +4439,8 @@
         // no history yet
         histIdx = 0;
-        // initialize the filter
-        initFilter();
+        // clear the jitter filter
+        jfLow = jfHigh = 0;
     // Collect a reading from the plunger sensor.  The main loop calls
@@ -4455,9 +4457,6 @@
         PlungerReading r;
         if (plungerSensor->read(r))
-            // filter the raw sensor reading
-            applyPreFilter(r);
             // Pull the previous reading from the history
             const PlungerReading &prv = nthHist(0);
@@ -4808,8 +4807,8 @@
             if (++histIdx >= countof(hist))
                 histIdx = 0;
-            // apply the post-processing filter
-            zf = applyPostFilter();
+            // apply the jitter filter
+            zf = jitterFilter(z);
@@ -4847,7 +4846,6 @@
             if (plungerSensor->read(r))
                 // got a reading - use it as the initial zero point
-                applyPreFilter(r);
        = r.pos;
@@ -4912,206 +4910,35 @@
     bool isFiring() { return firing == 3; }
-    // Auto-zeroing timer
-    Timer autoZeroTimer;
-    // Plunger data filtering mode:  optionally apply filtering to the raw 
-    // plunger sensor readings to try to reduce noise in the signal.  This
-    // is designed for the TSL1410/12 optical sensors, where essentially all
-    // of the noise in the signal comes from lack of sharpness in the shadow
-    // edge.  When the shadow is blurry, the edge detector has to pick a pixel,
-    // even though the edge is actually a gradient spanning several pixels.
-    // The edge detection algorithm decides on the exact pixel, but whatever
-    // the algorithm, the choice is going to be somewhat arbitrary given that
-    // there's really no one pixel that's "the edge" when the edge actually
-    // covers multiple pixels.  This can make the choice of pixel sensitive to
-    // small changes in exposure and pixel respose from frame to frame, which
-    // means that the reported edge position can move by a pixel or two from
-    // one frame to the next even when the physical plunger is perfectly still.
-    // That's the noise we're talking about.
-    //
-    // We previously applied a mild hysteresis filter to the signal to try to
-    // eliminate this noise.  The filter tracked the average over the last
-    // several samples, and rejected readings that wandered within a few
-    // pixels of the average.  If a certain number of readings moved away from
-    // the average in the same direction, even by small amounts, the filter
-    // accepted the changes, on the assumption that they represented actual
-    // slow movement of the plunger.  This filter was applied after the firing
-    // detection.
-    //
-    // I also tried a simpler filter that rejected changes that were too fast
-    // to be physically possible, as well as changes that were very close to
-    // the last reported position (i.e., simple hysteresis).  The "too fast"
-    // filter was there to reject spurious readings where the edge detector
-    // mistook a bad pixel value as an edge.  
-    //
-    // The new "mode 2" edge detector (see ccdSensor.h) seems to do a better
-    // job of rejecting pixel-level noise by itself than the older "mode 0"
-    // algorithm did, so I removed the filtering entirely.  Any filtering has
-    // some downsides, so it's better to reduce noise in the underlying signal
-    // as much as possible first.  It seems possible to get a very stable signal
-    // now with a combination of the mode 2 edge detector and optimizing the
-    // physical sensor arrangement, especially optimizing the light source to
-    // cast as sharp as shadow as possible and adjusting the brightness to
-    // maximize bright/dark contrast in the image.
-    //
-    //   0 = No filtering (current default)
-    //   1 = Filter the data after firing detection using moving average
-    //       hysteresis filter (old version, used in most 2016 releases)
-    //   2 = Filter the data before firing detection using simple hysteresis
-    //       plus spurious "too fast" motion rejection
-    //
-    // Disable all filtering
-    inline void applyPreFilter(PlungerReading &r) { }
-    inline int applyPostFilter() { return z; }
-    // Apply pre-processing filter.  This filter is applied to the raw
-    // value coming off the sensor, before calibration or fire-event
-    // processing.
-    void applyPreFilter(PlungerReading &r)
+    // Apply the jitter filter
+    int jitterFilter(int z)
-    }
-    // Figure the next post-processing filtered value.  This applies a
-    // hysteresis filter to the last raw z value and returns the 
-    // filtered result.
-    int applyPostFilter()
-    { 
-        if (firing <= 1)
-        {
-            // Filter limit - 5 samples.  Once we've been moving
-            // in the same direction for this many samples, we'll
-            // clear the history and start over.
-            const int filterMask = 0x1f;
-            // figure the last average
-            int lastAvg = int(filterSum / filterN);
+        // If the new reading is within the current window, simply re-use
+        // the last filtered reading.
+        if (z >= jfLow && z <= jfHigh)
+            return zf;
-            // figure the direction of this sample relative to the average,
-            // and shift it in to our bit mask of recent direction data
-            if (z != lastAvg)
-            {
-                // shift the new direction bit into the vector
-                filterDir <<= 1;
-                if (z > lastAvg) filterDir |= 1;
-            }
-            // keep only the last N readings, up to the filter limit
-            filterDir &= filterMask;
-            // if we've been moving consistently in one direction (all 1's
-            // or all 0's in the direction history vector), reset the average
-            if (filterDir == 0x00 || filterDir == filterMask) 
-            {
-                // motion away from the average - reset the average
-                filterDir = 0x5555;
-                filterN = 1;
-                filterSum = (lastAvg + z)/2;
-                return int16_t(filterSum);
-            }
-            else
-            {
-                // we're directionless - return the new average, with the 
-                // new sample included
-                filterSum += z;
-                ++filterN;
-                return int16_t(filterSum / filterN);
-            }
+        // The new reading is outside the current window.  Push the window
+        // over so that the new reading is at the outside edge.
+        if (z < jfLow)
+        {
+            // the new reading is below the current window, so move the
+            // window such that the new reading is at the bottom of the window
+            jfLow = z;
+            jfHigh = z + cfg.plunger.jitterWindow;
-            // firing mode - skip the filter
-            filterN = 1;
-            filterSum = z;
-            filterDir = 0x5555;
-            return z;
+            // the new reading is above the current window, so move the
+            // window such that the new reading is at the top of the window
+            jfHigh = z;
+            jfLow = z - cfg.plunger.jitterWindow;
-    }
-    // Apply pre-processing filter.  This filter is applied to the raw
-    // value coming off the sensor, before calibration or fire-event
-    // processing.
-    void applyPreFilter(PlungerReading &r)
-    {
-        // get the previous raw reading
-        PlungerReading prv = pre.raw;
-        // the new reading is the previous raw reading next time, no 
-        // matter how we end up filtering it
-        pre.raw = r;
-        // If it's too big an excursion from the previous raw reading,
-        // ignore it and repeat the previous reported reading.  This
-        // filters out anomalous spikes where we suddenly jump to a
-        // level that's too far away to be possible.  Real plungers
-        // take about 60ms to travel the full distance when released,
-        // so assuming constant acceleration, the maximum realistic
-        // speed is about 2.200 distance units (on our 0..0xffff scale)
-        // per microsecond.
-        //
-        // On the other hand, if the new reading is too *close* to the
-        // previous reading, use the previous reported reading.  This
-        // filters out jitter around a stationary position.
-        const float maxDist = 2.184f*uint32_t(r.t - prv.t);
-        const int minDist = 256;
-        const int delta = abs(r.pos - prv.pos);
-        if (maxDist > minDist && delta > maxDist)
-        {
-            // too big an excursion - discard this reading by reporting
-            // the last reported reading instead
-            r.pos = pre.reported;
-        }
-        else if (delta < minDist)
-        {
-            // too close to the prior reading - apply hysteresis
-            r.pos = pre.reported;
-        }
-        else
-        {
-            // the reading is in range - keep it, and remember it as
-            // the last reported reading
-            pre.reported = r.pos;
-        }
-    }
-    // pre-filter data
-    struct PreFilterData {
-        PreFilterData() 
-            : reported(0) 
-        {
-            raw.t = 0;
-            raw.pos = 0;
-        }
-        PlungerReading raw;         // previous raw sensor reading
-        int reported;               // previous reported reading
-    } pre;
-    // Apply the post-processing filter.  This filter is applied after
-    // the fire-event processing.  In the past, this used hysteresis to
-    // try to smooth out jittering readings for a stationary plunger.
-    // We've switched to a different approach that massages the readings
-    // coming off the sensor before 
-    int applyPostFilter()
-    {
+        // use the new reading exactly as read from the sensor
         return z;
-    void initFilter()
-    {
-        filterSum = 0;
-        filterN = 1;
-        filterDir = 0x5555;
-    }
-    int64_t filterSum;
-    int64_t filterN;
-    uint16_t filterDir;
     // Calibration state.  During calibration mode, we watch for release
     // events, to measure the time it takes to complete the release
     // motion; and we watch for the plunger to come to reset after a
@@ -5139,6 +4966,12 @@
     long calRlsTimeSum;
     int calRlsTimeN;
+    // Auto-zeroing timer
+    Timer autoZeroTimer;
+    // Current jitter filter window
+    int jfLow, jfHigh;
     // set a firing mode
     inline void firingMode(int m) 
@@ -5589,8 +5422,8 @@
                 cfg.plunger.enabled = data[3] & 0x01;
                 // set the flag to do the save
-                saveConfigPending = needReset ? SAVE_CONFIG_AND_REBOOT : SAVE_CONFIG_ONLY;
-                saveConfigRebootTime = 0;
+                saveConfigState = needReset ? SAVE_CONFIG_AND_REBOOT : SAVE_CONFIG_ONLY;
+                saveConfigPostTime = 0;
@@ -5636,10 +5469,15 @@
         case 6:
-            // 6 = Save configuration to flash.  Reboot after the delay
-            // time in seconds given in data[2].
-            saveConfigPending = SAVE_CONFIG_AND_REBOOT;
-            saveConfigRebootTime = data[2];
+            // 6 = Save configuration to flash.  Optionally reboot after the 
+            // delay time in seconds given in data[2].
+            //
+            // data[2] = delay time in seconds
+            // data[3] = flags:
+            //           0x01 -> do not reboot
+            saveConfigState = 
+                (data[3] & 0x01) != 0 ? SAVE_CONFIG_ONLY : SAVE_CONFIG_AND_REBOOT;
+            saveConfigPostTime = data[2];
         case 7:
@@ -6095,8 +5933,8 @@
     // start the PWM update polling timer
-    // Timer for configuration change reboots
-    ExtTimer saveConfigRebootTimer;
+    // Timer for configuration change followup timer
+    ExtTimer saveConfigPostTimer;
     // we're all set up - now just loop, processing sensor reports and 
     // host requests
@@ -6426,12 +6264,24 @@
         // if we have a reboot timer pending, check for completion
-        if (saveConfigRebootTimer.isRunning() 
-            && > saveConfigRebootTime)
-            reboot(js);
+        if (saveConfigPostTimer.isRunning() 
+            && > saveConfigPostTime)
+        {
+            // if a reboot is pending, execute it now
+            if (saveConfigState == SAVE_CONFIG_REBOOT)
+                reboot(js);
+            // done with the timer - reset it
+            saveConfigPostTimer.stop();
+            saveConfigPostTimer.reset();
+            // clear the save-config success flag
+            saveConfigSucceededFlag = 0;
+        }
         // if a config save is pending, do it now
-        if (saveConfigPending != 0)
+        if (saveConfigState == SAVE_CONFIG_ONLY  
+            || saveConfigState == SAVE_CONFIG_AND_REBOOT)
             // save the configuration
             if (saveConfigToFlash())
@@ -6439,13 +6289,19 @@
                 // report success in the status flags
                 saveConfigSucceededFlag = 0x40;
-                // if desired, reboot after the specified delay
-                if (saveConfigPending == SAVE_CONFIG_AND_REBOOT)
-                    saveConfigRebootTimer.start();
+                // start the followup timer
+                saveConfigPostTimer.start();
+                // The save is no longer pending.  Switch to reboot pending
+                // mode if desired.
+                saveConfigState = (saveConfigState == SAVE_CONFIG_AND_REBOOT ?
+                    SAVE_CONFIG_REBOOT : SAVE_CONFIG_IDLE);
-            // the save is no longer pending
-            saveConfigPending = 0;
+            else
+            {
+                // save failed - return to idle state
+                saveConfigState = SAVE_CONFIG_IDLE;
+            }
         // if we're disconnected, initiate a new connection