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	Sun Mar 19 05:30:53 2017 +0000
+++ b/main.cpp	Thu Mar 23 05:19:05 2017 +0000
@@ -216,6 +216,7 @@
 #include "math.h"
 #include "diags.h"
 #include "pinscape.h"
+#include "NewMalloc.h"
 #include "USBJoystick.h"
 #include "MMA8451Q.h"
 #include "tsl1410r.h"
@@ -313,108 +314,6 @@
-// --------------------------------------------------------------------------
-// Custom memory allocator.  We use our own version of malloc() for more
-// efficient memory usage, and to provide diagnostics if we run out of heap.
-// We can implement a more efficient malloc than the library can because we
-// can make an assumption that the library can't: allocations are permanent.
-// The normal malloc has to assume that allocations can be freed, so it has
-// to track blocks individually.  For the purposes of this program, though,
-// we don't have to do this because virtually all of our allocations are 
-// de facto permanent.  We only allocate dyanmic memory during setup, and 
-// once we set things up, we never delete anything.  This means that we can 
-// allocate memory in bare blocks without any bookkeeping overhead.
-// In addition, we can make a larger overall pool of memory available in
-// a custom allocator.  The RTL malloc() seems to have a pool of about 3K 
-// to work with, even though there really seems to be at least 8K left after 
-// reserving a reasonable amount of space for the stack.
-// halt with a diagnostic display if we run out of memory
-void HaltOutOfMem()
-    printf("\r\nOut Of Memory\r\n");
-    // halt with the diagnostic display (by looping forever)
-    for (;;)
-    {
-        diagLED(1, 0, 0);
-        wait_us(200000);
-        diagLED(1, 0, 1);
-        wait_us(200000);
-    }
-// For our custom malloc, we take advantage of the known layout of the
-// mbed library memory management.  The mbed library puts all of the
-// static read/write data at the low end of RAM; this includes the
-// initialized statics and the "ZI" (zero-initialized) statics.  The
-// malloc heap starts just after the last static, growing upwards as
-// memory is allocated.  The stack starts at the top of RAM and grows
-// downwards.  
-// To figure out where the free memory starts, we simply call the system
-// malloc() to make a dummy allocation the first time we're called, and 
-// use the address it returns as the start of our free memory pool.  The
-// first malloc() call presumably returns the lowest byte of the pool in
-// the compiler RTL's way of thinking, and from what we know about the
-// mbed heap layout, we know everything above this point should be free,
-// at least until we reach the lowest address used by the stack.
-// The ultimate size of the stack is of course dynamic and unpredictable.
-// In testing, it appears that we currently need a little over 1K.  To be
-// conservative, we'll reserve 2K for the stack, by taking it out of the
-// space at top of memory we consider fair game for malloc.
-// Note that we could do this a little more low-level-ly if we wanted.
-// The ARM linker provides a pre-defined extern char[] variable named 
-// Image$$RW_IRAM1$$ZI$$Limit, which is always placed just after the
-// last static data variable.  In principle, this tells us the start
-// of the available malloc pool.  However, in testing, it doesn't seem
-// safe to use this as the start of our malloc pool.  I'm not sure why,
-// but probably something in the startup code (either in the C RTL or 
-// the mbed library) is allocating from the pool before we get control. 
-// So we won't use that approach.  Besides, that would tie us even more
-// closely to the ARM compiler.  With our malloc() probe approach, we're
-// at least portable to any compiler that uses the same basic memory
-// layout, with the heap above the statics and the stack at top of 
-// memory; this isn't universal, but it's very typical.
-static char *xmalloc_nxt = 0;
-size_t xmalloc_rem = 0;
-void *xmalloc(size_t siz)
-    if (xmalloc_nxt == 0)
-    {
-        xmalloc_nxt = (char *)malloc(4);
-        xmalloc_rem = 0x20003000UL - 2*1024 - uint32_t(xmalloc_nxt);
-    }
-    siz = (siz + 3) & ~3;
-    if (siz > xmalloc_rem)
-        HaltOutOfMem();
-    char *ret = xmalloc_nxt;
-    xmalloc_nxt += siz;
-    xmalloc_rem -= siz;
-    return ret;
-// Overload operator new to call our custom malloc.  This ensures that
-// all 'new' allocations throughout the program (including library code)
-// go through our private allocator.
-void *operator new(size_t siz) { return xmalloc(siz); }
-void *operator new[](size_t siz) { return xmalloc(siz); }
-// Since we don't do bookkeeping to track released memory, 'delete' does
-// nothing.  In actual testing, this routine appears to never be called.
-// If it *is* ever called, it will simply leave the block in place, which
-// will make it unavailable for re-use but will otherwise be harmless.
-void operator delete(void *ptr) { }
 // ---------------------------------------------------------------------------
 // Forward declarations
@@ -2397,8 +2296,10 @@
     // current LOGICAL on/off state as reported to the host.
     uint8_t logState : 1;
-    // previous logical on/off state, when keys were last processed for USB 
-    // reports and local effects
+    // Previous logical on/off state, when keys were last processed for USB 
+    // reports and local effects.  This lets us detect edges (transitions)
+    // in the logical state, for effects that are triggered when the state
+    // changes rather than merely by the button being on or off.
     uint8_t prevLogState : 1;
     // Pulse state
@@ -2414,7 +2315,7 @@
     // door is open and off when the door is closed (or vice versa, but in either 
     // case, the switch state corresponds to the current state of the door at any
     // given time, rather than pulsing on state changes).  The "pulse mode"
-    // option brdiges this gap by generating a toggle key event each time
+    // option bridges this gap by generating a toggle key event each time
     // there's a change to the physical switch's state.
     // Pulse state:
@@ -2465,13 +2366,16 @@
     uint8_t data;       // key state byte for USB reports
 } mediaState = { false, 0 };
-// button scan interrupt ticker
-Ticker buttonTicker;
+// button scan interrupt timer
+Timeout scanButtonsTimeout;
 // Button scan interrupt handler.  We call this periodically via
 // a timer interrupt to scan the physical button states.  
 void scanButtons()
+    // schedule the next interrupt
+    scanButtonsTimeout.attach_us(&scanButtons, 1000);
     // scan all button input pins
     ButtonState *bs = buttonState, *last = bs + nButtons;
     for ( ; bs < last ; ++bs)
@@ -2591,7 +2495,7 @@
     // start the button scan thread
-    buttonTicker.attach_us(scanButtons, 1000);
+    scanButtonsTimeout.attach_us(scanButtons, 1000);
     // start the button state transition timer
@@ -3866,6 +3770,9 @@
 const uint8_t TV_RELAY_POWERON = 0x01;
 const uint8_t TV_RELAY_USB     = 0x02;
+// pulse timer for manual TV relay pulses
+Timer tvRelayManualTimer;
 // TV ON IR command state.  When the main PSU2 power state reaches
 // the IR phase, we use this sub-state counter to send the TV ON
 // IR signals.  We initialize to state 0 when the main state counter
@@ -3906,6 +3813,17 @@
 uint32_t tv_delay_time_us;
 void powerStatusUpdate(Config &cfg)
+    // If the manual relay pulse timer is past the pulse time, end the
+    // manual pulse.  The timer only runs when a pulse is active, so
+    // it'll never read as past the time limit if a pulse isn't on.
+    if (tvRelayManualTimer.read_us() > 250000)
+    {
+        // turn off the relay and disable the timer
+        tvRelayUpdate(TV_RELAY_USB, false);
+        tvRelayManualTimer.stop();
+        tvRelayManualTimer.reset();
+    }
     // Only update every 1/4 second or so.  Note that if the PSU2
     // circuit isn't configured, the initialization routine won't 
     // start the timer, so it'll always read zero and we'll always 
@@ -4110,15 +4028,6 @@
-// TV relay manual control timer.  This lets us pulse the TV relay
-// under manual control, separately from the TV ON timer.
-Ticker tv_manualTicker;
-void TVManualInt()
-    tv_manualTicker.detach();
-    tvRelayUpdate(TV_RELAY_USB, false);
 // Operate the TV ON relay.  This allows manual control of the relay
 // from the PC.  See protocol message 65 submessage 11.
@@ -4145,9 +4054,10 @@
     case 2:
-        // Pulse the relay.  Turn it on, then set our timer for 250ms.
+        // Turn the relay on and reset the manual TV pulse timer
         tvRelayUpdate(TV_RELAY_USB, true);
-        tv_manualTicker.attach(&TVManualInt, 0.25);
+        tvRelayManualTimer.reset();
+        tvRelayManualTimer.start();
@@ -4179,27 +4089,29 @@
 // delay time in seconds before rebooting.
 uint8_t saveConfigRebootTime;
+// status flag for successful config save - set to 0x40 on success
+uint8_t saveConfigSucceededFlag;
 // For convenience, a macro for the Config part of the NVM structure
 #define cfg (nvm.d.c)
 // flash memory controller interface
 FreescaleIAP iap;
-// NVM structure in memory.  This has to be aliend on a sector boundary,
-// since we have to be able to erase its page(s) in order to write it.
-// Further, we have to ensure that nothing else occupies any space within
-// the same pages, since we'll erase that entire space whenever we write.
-static const union
+// figure the flash address for the config data
+const NVM *configFlashAddr()
-    NVM nvm;      // the NVM structure
-    char guard[((sizeof(NVM) + SECTOR_SIZE - 1)/SECTOR_SIZE)*SECTOR_SIZE];
-flash_nvm_memory __attribute__ ((aligned(SECTOR_SIZE))) = { };
-// figure the flash address as a pointer
-NVM *configFlashAddr()
-    return (NVM *)&flash_nvm_memory;
+    // figure the number of sectors we need, rounding up
+    int nSectors = (sizeof(NVM) + SECTOR_SIZE - 1)/SECTOR_SIZE;
+    // figure the total size required from the number of sectors
+    int reservedSize = nSectors * SECTOR_SIZE;
+    // locate it at the top of memory
+    uint32_t addr = iap.flashSize() - reservedSize;
+    // return it as a read-only NVM pointer
+    return (const NVM *)addr;
 // Load the config from flash.  Returns true if a valid non-default
@@ -4226,7 +4138,7 @@
     // the free space, it won't collide with the linker area.
     // Figure how many sectors we need for our structure
-    NVM *flash = configFlashAddr();
+    const NVM *flash = configFlashAddr();
     // if the flash is valid, load it; otherwise initialize to defaults
     bool nvm_valid = flash->valid();
@@ -4245,55 +4157,17 @@
     return nvm_valid;
-void saveConfigToFlash()
+// save the config - returns true on success, false on failure
+bool saveConfigToFlash()
     // make sure the plunger sensor isn't busy
     // get the config block location in the flash memory
     uint32_t addr = uint32_t(configFlashAddr());
-    // loop until we save it successfully
-    for (int i = 0 ; i < 5 ; ++i)
-    {
-        // show cyan while writing
-        diagLED(0, 1, 1);
-        // save the data
-, addr);
-        // diagnostic lights off
-        diagLED(0, 0, 0);
-        // verify the data
-        if (nvm.verify(addr))
-        {
-            // show a diagnostic success flash (rapid green)
-            for (int j = 0 ; j < 4 ; ++j)
-            {
-                diagLED(0, 1, 0);
-                wait_us(50000);
-                diagLED(0, 0, 0);
-                wait_us(50000);
-            }
-            // success - no need to write again
-            break;
-        }
-        else
-        {            
-            // Write failed.  For diagnostic purposes, flash red a few times.
-            // Then go back through the loop to make another attempt at the
-            // write.
-            for (int j = 0 ; j < 5 ; ++j)
-            {
-                diagLED(1, 0, 0);
-                wait_us(50000);
-                diagLED(0, 0, 0);
-                wait_us(50000);
-            }
-        }
-    }
+    // save the data    
+    return, addr);
 // ---------------------------------------------------------------------------
@@ -5709,7 +5583,7 @@
                 nvm.valid(),        // a config is loaded if the config memory block is valid
                 true,               // we support sbx/pbx extensions
                 true,               // we support the new accelerometer settings
-                xmalloc_rem);       // remaining memory size
+                mallocBytesFree()); // remaining memory size
         case 5:
@@ -5962,11 +5836,6 @@
     // say hello to the debug console, in case it's connected
     printf("\r\nPinscape Controller starting\r\n");
-    // debugging: print memory config info
-    //    -> no longer very useful, since we use our own custom malloc/new allocator (see xmalloc() above)
-    // {int *a = new int; printf("Stack=%lx, heap=%lx, free=%ld\r\n", (long)&a, (long)a, (long)&a - (long)a);} 
     // clear the I2C connection
@@ -6383,7 +6252,8 @@
         uint16_t statusFlags = 
             cfg.plunger.enabled             // 0x01
             | nightMode                     // 0x02
-            | ((psu2_state & 0x07) << 2);   // 0x04 0x08 0x10
+            | ((psu2_state & 0x07) << 2)    // 0x04 0x08 0x10
+            | saveConfigSucceededFlag;      // 0x40
         if (IRLearningMode != 0)
             statusFlags |= 0x20;
@@ -6513,7 +6383,8 @@
         if (saveConfigPending != 0)
             // save the configuration
-            saveConfigToFlash();
+            if (saveConfigToFlash())
+                saveConfigSucceededFlag = 0x40;
             // if desired, reboot after the specified delay
             if (saveConfigPending == SAVE_CONFIG_AND_REBOOT)