diff --git a/libraries/AP_RAMTRON/AP_RAMTRON.cpp b/libraries/AP_RAMTRON/AP_RAMTRON.cpp
new file mode 100644
index 0000000000..838b6de74c
--- /dev/null
+++ b/libraries/AP_RAMTRON/AP_RAMTRON.cpp
@@ -0,0 +1,132 @@
+/*
+  driver for RAMTRON FRAM persistent memory devices. These are used
+  for parameter and waypoint storage on most FMUv1, FMUv2, FMUv3 and FMUv4
+  boards
+ */
+
+#include "AP_RAMTRON.h"
+
+extern const AP_HAL::HAL &hal;
+
+// register numbers
+#define RAMTRON_RDID      0x9f
+#define RAMTRON_READ      0x03
+#define RAMTRON_RDSR      0x05
+#define RAMTRON_WREN      0x06
+#define RAMTRON_WRITE     0x02
+
+/*
+  list of supported devices. Thanks to NuttX ramtron driver
+ */
+const AP_RAMTRON::ramtron_id AP_RAMTRON::ramtron_ids[] = {
+    { 0x21, 0x00, 16,  2}, // FM25V01
+    { 0x21, 0x08, 16,  2}, // FM25V01A
+    { 0x22, 0x00, 32,  2}, // FM25V02
+    { 0x22, 0x08, 32,  2}, // FM25V02A
+    { 0x22, 0x01, 32,  2}, // FM25VN02
+    { 0x23, 0x00, 64,  2}, // FM25V05
+    { 0x23, 0x01, 64,  2}, // FM25VN05
+    { 0x24, 0x00, 128, 3}, // FM25V10
+    { 0x24, 0x01, 128, 3}, // FM25VN10
+    { 0x25, 0x08, 256, 3}, // FM25V20A
+    { 0x26, 0x08, 512, 3}, // CY15B104Q
+    { 0x27, 0x03, 128, 3}, // MB85RS1MT
+    { 0x05, 0x09, 32,  3}, // B85RS256B
+};
+
+// initialise the driver
+bool AP_RAMTRON::init(void)
+{
+    dev = hal.spi->get_device("ramtron");
+    if (!dev || !dev->get_semaphore()->take(0)) {
+        return false;
+    }
+
+    struct rdid {
+        uint8_t manufacturer[6];
+        uint8_t memory;
+        uint8_t id1;
+        uint8_t id2;
+    } rdid;
+    if (!dev->read_registers(RAMTRON_RDID, (uint8_t *)&rdid, sizeof(rdid))) {
+        dev->get_semaphore()->give();
+        return false;
+    }
+    dev->get_semaphore()->give();
+
+    for (uint8_t i=0; i<ARRAY_SIZE(ramtron_ids); i++) {
+        if (ramtron_ids[i].id1 == rdid.id1 &&
+            ramtron_ids[i].id2 == rdid.id2) {
+            id = i;
+            return true;
+        }
+    }
+    hal.console->printf("Unknown RAMTRON manufacturer=%02x memory=%02x id1=%02x id2=%02x\n",
+                        rdid.manufacturer[0], rdid.memory, rdid.id1, rdid.id2);
+    return false;
+}
+
+/*
+  send a command and offset
+ */
+void AP_RAMTRON::send_offset(uint8_t cmd, uint32_t offset)
+{
+    if (ramtron_ids[id].addrlen == 3) {
+        uint8_t b[4] = { cmd, uint8_t((offset>>16)&0xFF), uint8_t((offset>>8)&0xFF), uint8_t(offset&0xFF) };
+        dev->transfer(b, sizeof(b), nullptr, 0);
+    } else /* len 2 */ {
+        uint8_t b[3] = { cmd, uint8_t((offset>>8)&0xFF), uint8_t(offset&0xFF) };
+        dev->transfer(b, sizeof(b), nullptr, 0);
+    }
+}
+
+// read from device
+bool AP_RAMTRON::read(uint32_t offset, uint8_t *buf, uint32_t size)
+{
+    const uint8_t maxread = 128;
+    while (size > maxread) {
+        if (!read(offset, buf, maxread)) {
+            return false;
+        }
+        offset += maxread;
+        buf += maxread;
+        size -= maxread;
+    }
+
+    if (!dev->get_semaphore()->take(0)) {
+        return false;
+    }
+    dev->set_chip_select(true);
+
+    send_offset(RAMTRON_READ, offset);
+    
+    // get data
+    dev->transfer(nullptr, 0, buf, size);
+
+    dev->set_chip_select(false);
+    dev->get_semaphore()->give();
+
+    return true;
+}
+
+// write to device
+bool AP_RAMTRON::write(uint32_t offset, const uint8_t *buf, uint32_t size)
+{
+    if (!dev->get_semaphore()->take(0)) {
+        return false;
+    }
+    // write enable
+    uint8_t r = RAMTRON_WREN;
+    dev->transfer(&r, 1, nullptr, 0);
+  
+    dev->set_chip_select(true);
+
+    send_offset(RAMTRON_WRITE, offset);
+
+    dev->transfer(buf, size, nullptr, 0);
+
+    dev->set_chip_select(false);
+
+    dev->get_semaphore()->give();
+    return true;
+}
diff --git a/libraries/AP_RAMTRON/AP_RAMTRON.h b/libraries/AP_RAMTRON/AP_RAMTRON.h
new file mode 100644
index 0000000000..1b8cd1559c
--- /dev/null
+++ b/libraries/AP_RAMTRON/AP_RAMTRON.h
@@ -0,0 +1,36 @@
+/*
+  driver for RAMTRON FRAM persistent memory devices
+ */
+#pragma once
+
+#include <AP_Common/AP_Common.h>
+#include <AP_HAL/AP_HAL.h>
+
+class AP_RAMTRON {
+public:
+    // initialise the driver
+    bool init(void);
+
+    // get size in bytes
+    uint32_t get_size(void) const { return ramtron_ids[id].size_kbyte*1024UL; }
+
+    // read from device
+    bool read(uint32_t offset, uint8_t *buf, uint32_t size);
+
+    // write to device
+    bool write(uint32_t offset, const uint8_t *buf, uint32_t size);
+
+private:
+    AP_HAL::OwnPtr<AP_HAL::SPIDevice> dev;
+
+    struct ramtron_id {
+        uint8_t id1, id2;
+        uint16_t size_kbyte;
+        uint8_t addrlen;
+    };
+    static const struct ramtron_id ramtron_ids[];
+    uint8_t id;
+
+    // send offset of transfer
+    void send_offset(uint8_t cmd, uint32_t offset);
+};