diff --git a/lib/hardware/GwHardware.h b/lib/hardware/GwHardware.h
index ae4e640..273f424 100644
--- a/lib/hardware/GwHardware.h
+++ b/lib/hardware/GwHardware.h
@@ -322,4 +322,11 @@
   #define CFGMODE_ledBrightness GwConfigInterface::HIDDEN
 #endif
 
+#ifdef GWSPI0_CLK
+  #define _GWSPI
+#endif
+#ifdef GWSPI1_CLK
+  #define _GWSPI
+#endif
+
 #endif
diff --git a/lib/iictask/GwIicSensors.h b/lib/iictask/GwIicSensors.h
index 51f787c..c3d21b4 100644
--- a/lib/iictask/GwIicSensors.h
+++ b/lib/iictask/GwIicSensors.h
@@ -14,8 +14,7 @@
 using BusType=TwoWire;
 using IICSensorList=SensorList<BusType>;
 using IICSensorBase=SensorBase<BusType>;
-#define CFG_GET(name,prefix) \
-    cfg->getValue(name, GwConfigDefinitions::prefix ## name)
+
 
 template <class CFG>
 bool addPressureXdr(GwApi *api, CFG &cfg)
diff --git a/lib/sensors/GwSensor.h b/lib/sensors/GwSensor.h
index 4988dd8..e33aef3 100644
--- a/lib/sensors/GwSensor.h
+++ b/lib/sensors/GwSensor.h
@@ -19,7 +19,6 @@
 template<typename BUS>
 class SensorBase{
     public:
-    using BusType=BUS;
     int busId=0;
     int iid=99; //N2K instanceId
     int addr=-1;
@@ -46,4 +45,8 @@ class SensorList : public std::vector<SensorBase<BUS>*>{
     }
     using std::vector<SensorBase<BUS>*>::vector;
 };
+
+#define CFG_GET(name,prefix) \
+    cfg->getValue(name, GwConfigDefinitions::prefix ## name)
+    
 #endif
\ No newline at end of file
diff --git a/lib/spitask/GWDMS22B.cpp b/lib/spitask/GWDMS22B.cpp
new file mode 100644
index 0000000..cd4fed8
--- /dev/null
+++ b/lib/spitask/GWDMS22B.cpp
@@ -0,0 +1,62 @@
+/*
+  (C) Andreas Vogel andreas@wellenvogel.de
+  This code is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+  This code is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+#include "GWDMS22B.h"
+#define PREFIX1 "DMS22B11"
+class GWDMS22B : public SSISensor{
+    uint32_t zero=2047;
+    public:
+    using SSISensor::SSISensor;
+    virtual bool preinit(GwApi * api){
+        GwLog *logger=api->getLogger();
+        LOG_DEBUG(GwLog::LOG,"DMS22B configured, prefix=%s",prefix.c_str());
+        api->addCapability(prefix,"true");
+        return true;
+    }
+    virtual void measure(GwApi * api,BusType *bus, int counterId){
+        GwLog *logger=api->getLogger();
+        uint32_t value=0;
+        esp_err_t res=readData(value);
+        if (res != ESP_OK){
+            LOG_DEBUG(GwLog::ERROR,"unable to measure %s: %d",prefix.c_str(),(int)res);
+        }
+        LOG_DEBUG(GwLog::LOG,"measure %s : %d",prefix.c_str(),value);
+    }
+    #define DMS22B(prefix)\
+        CFG_GET(act,prefix); \
+        CFG_GET(iid,prefix); \
+        CFG_GET(intv,prefix); \
+        CFG_GET(zero,prefix);
+    virtual void readConfig(GwConfigHandler *cfg){
+        if (prefix == PREFIX1){
+            DMS22B(DMS22B11);
+            busId=GWSPIHOST1;
+            bits=12;
+            clock=500000;
+            #ifdef GWDMS22B11_CS
+            cs=GWDMS22B11_CS;
+            #else
+            cs=-1;
+            #endif
+        }
+        //TODO: other
+    }
+};
+
+void registerDMS22B(GwApi *api,SpiSensorList &sensors){
+    #ifdef GWDMS22B11
+        GWDMS22B *dms=new GWDMS22B(api,PREFIX1);
+        sensors.add(dms);
+    #endif
+}
diff --git a/lib/spitask/GWDMS22B.h b/lib/spitask/GWDMS22B.h
new file mode 100644
index 0000000..5ef9bb5
--- /dev/null
+++ b/lib/spitask/GWDMS22B.h
@@ -0,0 +1,22 @@
+/*
+  (C) Andreas Vogel andreas@wellenvogel.de
+  This code is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+  This code is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+/*
+SSI sensor DMS22B - https://www.mouser.de/datasheet/2/54/bour_s_a0011704065_1-2262614.pdf
+*/
+#ifndef _GWDMS22B_H
+#define _GWDMS22B_H
+#include "GwSpiSensor.h"
+void registerDMS22B(GwApi *api,SpiSensorList &sensors);
+#endif
\ No newline at end of file
diff --git a/lib/spitask/GwSpiSensor.h b/lib/spitask/GwSpiSensor.h
new file mode 100644
index 0000000..76f9e64
--- /dev/null
+++ b/lib/spitask/GwSpiSensor.h
@@ -0,0 +1,136 @@
+/*
+  (C) Andreas Vogel andreas@wellenvogel.de
+  This code is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+  This code is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+#ifndef _GWSPISENSOR_H
+#define _GWSPISENSOR_H
+#include <driver/spi_master.h>
+#include "GwSensor.h"
+#include <memory>
+
+class SPIBus{
+    spi_host_device_t hd;
+    bool initialized=false;
+    public:
+    SPIBus(spi_host_device_t h):hd(h){}
+    bool init(GwLog*logger,int mosi=-1,int miso=-1,int clck=-1){
+        spi_bus_config_t buscfg = {
+        .mosi_io_num = mosi,
+        .miso_io_num = miso,
+        .sclk_io_num = clck,
+        .quadwp_io_num = -1,
+        .quadhd_io_num = -1,
+        .max_transfer_sz = 0
+        };   
+        esp_err_t res=spi_bus_initialize(hd,&buscfg,0);
+        if (res == ESP_OK){
+            LOG_DEBUG(GwLog::LOG,"initialzed SPI bus %d,mosi=%d,miso=%d,clock=%d",
+                (int)hd,mosi,miso,clck);
+            initialized=true;
+        }
+        else{
+            LOG_DEBUG(GwLog::ERROR,"unable to initialize SPI bus %d,mosi=%d,miso=%d,clock=%d, error=%d",
+            (int)hd,mosi,miso,clck,(int)res);
+        }
+        return initialized;
+    }
+    spi_host_device_t host() const { return hd;} 
+};
+
+using BusType=SPIBus;
+
+class SSIDevice{
+    spi_device_handle_t spi;
+    spi_host_device_t host;
+    bool initialized=false;
+    int bits=12;
+    public:
+    SSIDevice(const SPIBus *bus):host(bus->host()){}
+    bool init(GwLog*logger,int clock,int cs=-1,int bits=12){
+        this->bits=bits;
+       spi_device_interface_config_t devcfg = {
+        .command_bits = 0,
+        .address_bits = 0,
+        .dummy_bits = 0,
+        .mode = 2,
+        .duty_cycle_pos = 128,
+        .cs_ena_pretrans = 0,
+        .cs_ena_posttrans =0,
+        .clock_speed_hz = clock, 
+        .input_delay_ns =0,
+        .spics_io_num = cs,             //CS pin
+        .queue_size = 1 //see https://github.com/espressif/esp-idf/issues/9450
+        };
+        esp_err_t res=spi_bus_add_device(host,&devcfg,&spi);
+        if (res == ESP_OK){
+            LOG_DEBUG(GwLog::LOG,"added SSI device to bus %d, cs=%d, clock=%d",
+                (int)host,cs,clock);
+            initialized=true;
+        }
+        else{
+            LOG_DEBUG(GwLog::ERROR,"unable to add SSI device to bus %d, cs=%d, clock=%d, error=%d",
+                (int)host,cs,clock,(int) res);
+        }
+        return initialized;
+    }
+    bool isInitialized() const { return initialized;}
+    spi_device_handle_t & device(){return spi;}
+
+};
+
+
+class SSISensor : public SensorBase<BusType>{
+    std::unique_ptr<SSIDevice> device;
+    protected:
+    int bits=12;
+    int mask=0xffff;
+    int cs=-1;
+    int clock=0;
+    bool act=false;
+    virtual bool initSSI(GwLog*logger,const SPIBus *bus,
+        int clock,int cs, int bits){
+            mask= (1 << bits)-1;
+            device.reset(new SSIDevice(bus));
+            return device->init(logger,clock,cs,bits);
+        }
+        esp_err_t readData(uint32_t &res)
+        {
+            struct spi_transaction_t ta = {
+                .flags = SPI_TRANS_USE_RXDATA,
+                .cmd = 0,
+                .addr = 0,
+                .length = bits+1,
+                .rxlength = 0};
+            esp_err_t ret = spi_device_queue_trans(device->device(), &ta, portMAX_DELAY);
+            if (ret != ESP_OK) return ret;
+            struct spi_transaction_t *rs = NULL;
+            ret = spi_device_get_trans_result(device->device(), &rs, portMAX_DELAY);
+            if (ret != ESP_OK) return ret;
+            if (rs == NULL) return ESP_ERR_INVALID_RESPONSE;
+            res=SPI_SWAP_DATA_RX(*(uint32_t*)rs->rx_data,bits+1);
+            res&=mask;
+            return ESP_OK;
+        }
+
+    public:
+    using SensorBase<BusType>::SensorBase;
+    virtual bool isActive(){return act;};
+    virtual bool initDevice(GwApi *api,BusType *bus){
+        return initSSI(api->getLogger(),bus, clock,cs,bits);
+    };
+    
+};
+using SpiSensorList=SensorList<BusType>;
+#define GWSPIHOST1 SPI2_HOST
+#define GWSPIHOST2 SPI3_HOST
+#endif
\ No newline at end of file
diff --git a/lib/spitask/GwSpiTask.cpp b/lib/spitask/GwSpiTask.cpp
new file mode 100644
index 0000000..14e02a9
--- /dev/null
+++ b/lib/spitask/GwSpiTask.cpp
@@ -0,0 +1,139 @@
+/*
+  (C) Andreas Vogel andreas@wellenvogel.de
+  This code is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+  This code is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+#include "GwSpiTask.h"
+#include "GwSpiSensor.h"
+#include "GWDMS22B.h"
+#include "GwTimer.h"
+
+static SPIBus bus1(GWSPIHOST1);
+static SPIBus bus2(GWSPIHOST2);
+
+static SpiSensorList sensors;
+
+#ifdef GWSPI1_CLK
+static const int spi1clk=GWSPI1_CLK;
+#else
+static const int spi1clk=-1;
+#endif
+#ifdef GWSPI1_MISO
+static const int spi1miso=GWSPI1_MISO;
+#else
+static const int spi1miso=-1;
+#endif
+#ifdef GWSPI1_MOSI
+static const int spi1mosi=GWSPI1_MOSI;
+#else
+static const int spi1mosi=-1;
+#endif
+
+#ifdef GWSPI2_CLK
+static const int spi2clk=GWSPI2_CLK;
+#else
+static const int spi2clk=-1;
+#endif
+#ifdef GWSPI2_MISO
+static const int spi2miso=GWSPI2_MISO;
+#else
+static const int spi2miso=-1;
+#endif
+#ifdef GWSPI2_MOSI
+static const int spi2mosi=GWSPI2_MOSI;
+#else
+static const int spi2mosi=-1;
+#endif
+
+#define _GWSPI
+void runSpiTask(GwApi *api){
+    GwLog *logger=api->getLogger();
+    std::map<int,SPIBus *> buses;
+    for (auto && sensor:sensors){
+        int busId=sensor->busId;
+        auto bus=buses.find(busId);
+        if (bus == buses.end()){
+            switch (busId)
+            {
+            case 1:
+                if (spi1clk < 0){
+                    LOG_DEBUG(GwLog::ERROR,"SPI bus 1 not configured, cannot create %s",sensor->prefix.c_str());
+                }
+                else{
+                    if (bus1.init(logger,spi1miso,spi1mosi,spi1clk)){
+                        buses[busId]=&bus1;
+                    }
+                }
+                break;
+            case 2:
+                if (spi2clk < 0){
+                    LOG_DEBUG(GwLog::ERROR,"SPI bus 2 not configured, cannot create %s",sensor->prefix.c_str());
+                }
+                else{
+                    if (bus2.init(logger,spi2miso,spi2mosi,spi2clk)){
+                        buses[busId]=&bus2;
+                    }
+                }
+                break;
+            default:
+                LOG_DEBUG(GwLog::ERROR,"invalid busid %d for %s",busId,sensor->prefix.c_str());
+            }
+        }
+    }
+    GwConfigHandler *config=api->getConfig();
+    bool runLoop=false;
+    GwIntervalRunner timers;
+    int counterId=api->addCounter("spisensors");
+    for (auto && sensor:sensors){
+        if (!sensor->isActive()) continue;
+        auto bus=buses.find(sensor->busId);
+        if (bus == buses.end()){
+            continue;
+        }
+        bool rt=sensor->initDevice(api,bus->second);
+        if (rt){
+            runLoop=true;
+            timers.addAction(sensor->intv,[bus,api,sensor,counterId](){
+                sensor->measure(api,bus->second,counterId);
+            });
+        }
+    }
+    if (! runLoop){
+        LOG_DEBUG(GwLog::LOG,"nothing to do for SPI task, finish");
+        vTaskDelete(NULL);
+        return;
+    }
+    while(true){
+        delay(100);
+        timers.loop();
+    }
+    vTaskDelete(NULL);
+}
+
+
+void initSpiTask(GwApi *api){
+    GwLog *logger=api->getLogger();
+    #ifndef _GWSPI
+        return;
+    #endif
+    registerDMS22B(api,sensors);
+    bool addTask=false;
+    for (auto && sensor:sensors){
+        if (sensor->preinit(api)) addTask=true;
+    }
+    if (addTask){
+        api->addUserTask(runSpiTask,"spiTask",3000);   
+    }
+    else{
+        LOG_DEBUG(GwLog::LOG,"no SPI sensors defined");
+    }
+}
\ No newline at end of file
diff --git a/lib/spitask/GwSpiTask.h b/lib/spitask/GwSpiTask.h
new file mode 100644
index 0000000..ddcac8b
--- /dev/null
+++ b/lib/spitask/GwSpiTask.h
@@ -0,0 +1,20 @@
+/*
+  (C) Andreas Vogel andreas@wellenvogel.de
+  This code is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+  This code is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+#ifndef _GWSPITASK_H
+#define _GWSPITASK_H
+#include "GwApi.h"
+void initSpiTask(GwApi *api);
+DECLARE_INITFUNCTION(initSpiTask);
+#endif
\ No newline at end of file
diff --git a/lib/spitask/config.json b/lib/spitask/config.json
new file mode 100644
index 0000000..4c9d13c
--- /dev/null
+++ b/lib/spitask/config.json
@@ -0,0 +1,92 @@
+[
+    {
+        "type": "array",
+        "name": "DMS22B",
+        "replace": [
+            {
+                "b": "1",
+                "i": "11",
+                "n": "11"
+            },
+            {
+                "b": "1",
+                "i": "12",
+                "n": "12"
+            },
+            {
+                "b": "1",
+                "i": "13",
+                "n": "13"
+            },
+            {
+                "b": "2",
+                "i": "21",
+                "n": "21"
+            },
+            {
+                "b": "2",
+                "i": "22",
+                "n": "22"
+            },
+            {
+                "b": "2",
+                "i": "23",
+                "n": "23"
+            }
+
+
+        ],
+        "children": [
+            {
+                "name": "DMS22B$iact",
+                "label": "DMS22BX$i enable",
+                "type": "boolean",
+                "default": "true",
+                "description": "Enable the $i. SSI DMS22B rotary encoder (bus $b)",
+                "category": "spisensors$b",
+                "capabilities": {
+                    "DMS22B$i": "true"
+                }
+            },
+            {
+                "name": "DMS22B$iiid",
+                "label": "DMS22B$i N2K iid",
+                "type": "number",
+                "default": "$n",
+                "description": "the N2K instance id for the $i. DMS22B Rotary Encoder ",
+                "category": "spisensors$b",
+                "min": 0,
+                "max": 253,
+                "check": "checkMinMax",
+                "capabilities": {
+                    "DMS22B$i": "true"
+                }
+            },
+            {
+                "name": "DMS22B$iintv",
+                "label": "DMS22B$i Interval",
+                "type": "number",
+                "default": 2,
+                "description": "Interval(s) to query DMS22B rotation (0.5...10)",
+                "category": "spisensors$b",
+                "min": 0.5,
+                "max": 10,
+                "check": "checkMinMax",
+                "capabilities": {
+                    "DMS22B$i": "true"
+                }
+            },
+            {
+                "name": "DMS22B$izero",
+                "label": "DMS22B$i Zero",
+                "type": "number",
+                "default": 2,
+                "description": "Zero position (0...2^bits-1)",
+                "category": "spisensors$b",
+                "capabilities": {
+                    "DMS22B$i": "true"
+                }
+            }
+        ]
+    }
+]
\ No newline at end of file
diff --git a/lib/spitask/platformio.ini b/lib/spitask/platformio.ini
new file mode 100644
index 0000000..d0c8f21
--- /dev/null
+++ b/lib/spitask/platformio.ini
@@ -0,0 +1,14 @@
+[platformio]
+#basically for testing purposes
+[env:m5stack-atom-spidms22b]
+extends = sensors
+board = m5stack-atom
+lib_deps = 
+    ${env.lib_deps}
+    ${sensors.lib_deps}
+build_flags=
+    -D GWSPI1_CLK=21
+    -D GWSPI1_MISO=25
+    -D GWDMS22B11
+    -D GWDMS22B11_CS=22
+    ${env.build_flags}