diff --git a/apps/hwtest/lowlevel/Makefile b/apps/hwtest/lowlevel/Makefile
new file mode 100644
index 000000000..85e1b6960
--- /dev/null
+++ b/apps/hwtest/lowlevel/Makefile
@@ -0,0 +1,5 @@
+objs += $(addprefix apps/hwtest/lowlevel/,\
+  lowlevel.o \
+)
+
+apps/hwtest/lowlevel/lowlevel.o: SFLAGS += -O3
diff --git a/apps/hwtest/lowlevel/lowlevel.cpp b/apps/hwtest/lowlevel/lowlevel.cpp
new file mode 100644
index 000000000..ff466c7cb
--- /dev/null
+++ b/apps/hwtest/lowlevel/lowlevel.cpp
@@ -0,0 +1,195 @@
+#include <stddef.h>
+#include <ion.h>
+#include <poincare.h>
+
+typedef void (*CommandFunction)(const char * input);
+
+void command_ping(const char * input);
+void command_mcu_serial(const char * input);
+
+class CommandHandler {
+public:
+  constexpr CommandHandler(const char * name, CommandFunction function) :
+    m_name(name), m_function(function) {}
+  bool valid() const;
+  bool handle(const char * command) const;
+private:
+  bool matches(const char * command) const;
+  const char * m_name;
+  CommandFunction m_function;
+};
+
+bool CommandHandler::valid() const {
+  return (m_name != nullptr && m_function != nullptr);
+}
+
+bool CommandHandler::handle(const char * command) const {
+  if (matches(command)) {
+    size_t nameLength = strlen(m_name);
+    if (command[nameLength] == '=') {
+      m_function(command+nameLength+1); // Skip the "Equal character"
+    } else {
+      m_function(nullptr);
+    }
+    return true;
+  }
+  return false;
+}
+
+bool CommandHandler::matches(const char * command) const {
+  const char * c = command;
+  const char * n = m_name;
+  while (true) {
+    if (*n == NULL) {
+      if (*c == NULL || *c == '=') {
+        return true;
+      }
+    }
+    if (*c != *n) {
+      return false;
+    }
+    c++;
+    n++;
+  }
+}
+
+class CommandList {
+public:
+  constexpr CommandList(const CommandHandler * handlers) : m_handlers(handlers) {}
+  void dispatch(const char * command) const;
+private:
+  const CommandHandler * m_handlers;
+};
+
+void CommandList::dispatch(const char * command) const {
+  const CommandHandler * handler = m_handlers;
+  while (handler->valid()) {
+    if (handler->handle(command)) {
+      return;
+    }
+    handler++;
+  }
+  Ion::Console::writeLine("NOT_FOUND");
+}
+
+static const char * sSyntaxError = "SYNTAX_ERROR";
+
+void command_ping(const char * input) {
+  if (input != nullptr) {
+    Ion::Console::writeLine(sSyntaxError);
+    return;
+  }
+  Ion::Console::writeLine("PONG");
+}
+
+void command_mcu_serial(const char * input) {
+  if (input != nullptr) {
+    Ion::Console::writeLine(sSyntaxError);
+    return;
+  }
+  char response[11+24+1] = {'M', 'C', 'U', '_', 'S', 'E', 'R', 'I', 'A', 'L', '=', 0};
+  strlcpy(response+11, Ion::serialNumber(), 25);
+  Ion::Console::writeLine(response);
+}
+
+static inline int8_t hexChar(char c) {
+  if (c >= '0' && c <= '9') {
+    return (c - '0');
+  }
+  if (c >= 'A' && c <= 'F') {
+    return (c - 'A') + 0xA;
+  }
+  return -1;
+}
+static inline bool isHex(char c) { return hexChar(c) >= 0; }
+static inline uint32_t hexNumber(const char * s) {
+  uint32_t result = 0;
+  while (*s != NULL) {
+    result = (result << 4) | hexChar(*s++);
+  }
+  return result;
+}
+
+void command_led(const char * input) {
+  // Input must be of the form "0xAABBCC"
+  if (input == nullptr || input[0] != '0' || input[1] != 'x' || !isHex(input[2]) ||!isHex(input[3]) || !isHex(input[4]) || !isHex(input[5]) || !isHex(input[6]) || !isHex(input[7]) || input[8] != NULL) {
+    Ion::Console::writeLine(sSyntaxError);
+    return;
+  }
+  uint32_t hexColor = hexNumber(input+2);
+  KDColor ledColor = KDColor::RGB24(hexColor);
+  Ion::LED::setColor(ledColor);
+  Ion::Console::writeLine("OK");
+}
+
+void command_backlight(const char * input) {
+  // Input must be of the form "0xAA"
+  if (input == nullptr || input[0] != '0' || input[1] != 'x' || !isHex(input[2]) ||!isHex(input[3]) || input[4] != NULL) {
+    Ion::Console::writeLine(sSyntaxError);
+    return;
+  }
+  uint32_t brightness = hexNumber(input+2);
+  Ion::Backlight::setBrightness(brightness);
+  Ion::Console::writeLine("OK");
+}
+
+void command_adc(const char * input) {
+  if (input != nullptr) {
+    Ion::Console::writeLine(sSyntaxError);
+    return;
+  }
+  float result = Ion::Battery::voltage();
+  constexpr int precision = 8;
+  constexpr int bufferSize = Poincare::Complex::bufferSizeForFloatsWithPrecision(precision);
+  char responseBuffer[bufferSize+4] = {'A', 'D', 'C', '='}; // ADC=
+  Poincare::Complex::convertFloatToText(result, responseBuffer+4, bufferSize, precision);
+  Ion::Console::writeLine(responseBuffer);
+}
+
+void command_charge(const char * input) {
+  if (input != nullptr) {
+    Ion::Console::writeLine(sSyntaxError);
+    return;
+  }
+  if (Ion::Battery::isCharging()) {
+    Ion::Console::writeLine("CHARGE=ON");
+  } else {
+    Ion::Console::writeLine("CHARGE=OFF");
+  }
+}
+
+void command_keyboard(const char * input) {
+  if (input != nullptr) {
+    Ion::Console::writeLine(sSyntaxError);
+    return;
+  }
+  char result[9+Ion::Keyboard::NumberOfKeys+1] = { 'K', 'E', 'Y', 'B', 'O', 'A', 'R', 'D', '=' };
+  for (uint8_t i=0; i<Ion::Keyboard::NumberOfKeys; i++) {
+    result[9+i] = Ion::Keyboard::keyDown((Ion::Keyboard::Key)i) ? '1' : '0';
+  }
+  result[9+Ion::Keyboard::NumberOfKeys] = 0;
+  Ion::Console::writeLine(result);
+}
+
+constexpr CommandHandler handles[] = {
+  CommandHandler("PING", command_ping),
+  CommandHandler("MCU_SERIAL", command_mcu_serial),
+  CommandHandler("LED", command_led),
+  CommandHandler("BACKLIGHT", command_backlight),
+  CommandHandler("ADC", command_adc),
+  CommandHandler("CHARGE", command_charge),
+  CommandHandler("KEYBOARD", command_keyboard),
+  CommandHandler(nullptr, nullptr)
+};
+constexpr const CommandList sCommandList = CommandList(handles);
+
+constexpr int kMaxCommandLength = 255;
+
+void ion_app() {
+  char command[kMaxCommandLength];
+  while (true) {
+    Ion::Console::readLine(command, kMaxCommandLength);
+    sCommandList.dispatch(command);
+  }
+}
+
diff --git a/ion/include/ion.h b/ion/include/ion.h
index 5ae753fb6..5ae833362 100644
--- a/ion/include/ion.h
+++ b/ion/include/ion.h
@@ -4,6 +4,7 @@
 #include <ion/backlight.h>
 #include <ion/battery.h>
 #include <ion/charset.h>
+#include <ion/console.h>
 #include <ion/display.h>
 #include <ion/events.h>
 #include <ion/keyboard.h>
@@ -26,6 +27,8 @@ namespace Ion {
 void msleep(long ms);
 void usleep(long us);
 
+const char * serialNumber();
+
 /* CAUTION: This is a complete reset! */
 void reset();
 
diff --git a/ion/include/ion/console.h b/ion/include/ion/console.h
new file mode 100644
index 000000000..4f9600999
--- /dev/null
+++ b/ion/include/ion/console.h
@@ -0,0 +1,15 @@
+#ifndef ION_CONSOLE_H
+#define ION_CONSOLE_H
+
+namespace Ion {
+namespace Console {
+
+// The lines are NULL-terminated
+
+void writeLine(const char * line);
+void readLine(char * line, int maxLineLength);
+
+}
+}
+
+#endif
diff --git a/ion/src/device/Makefile b/ion/src/device/Makefile
index 986970daf..2a3870052 100644
--- a/ion/src/device/Makefile
+++ b/ion/src/device/Makefile
@@ -7,6 +7,7 @@ objs += $(addprefix ion/src/shared/, \
 objs += $(addprefix ion/src/device/, \
   backlight.o \
   battery.o\
+  console.o \
   device.o\
   display.o\
   keyboard.o\
@@ -25,6 +26,7 @@ objs += $(addprefix ion/src/device/, \
 ifneq ($(DEBUG),1)
 ifneq ($(COMPILER),llvm)
 ion/src/device/led.o: SFLAGS+=-O3
+ion/src/device/console.o: SFLAGS+=-O3
 ion/src/device/display.o: SFLAGS+=-O3
 endif
 endif
diff --git a/ion/src/device/battery.cpp b/ion/src/device/battery.cpp
index 6f66d20c4..02a5fab94 100644
--- a/ion/src/device/battery.cpp
+++ b/ion/src/device/battery.cpp
@@ -50,6 +50,11 @@ void init() {
   // Step 2 - Enable the ADC
   RCC.APB2ENR()->setADC1EN(true);
   ADC.CR2()->setADON(true);
+
+  // Configure the ADC channel
+  ADC.SQR1()->setL(0); // Always sample the same channel
+  ADC.SQR3()->setSQ1(ADCChannel);
+  ADC.SMPR()->setSamplingTime(ADCChannel, ADC::SMPR::SamplingTime::Cycles480); // Use the max sampling time
 }
 
 void shutdown() {
diff --git a/ion/src/device/console.cpp b/ion/src/device/console.cpp
new file mode 100644
index 000000000..435b69231
--- /dev/null
+++ b/ion/src/device/console.cpp
@@ -0,0 +1,81 @@
+#include <ion.h>
+#include "console.h"
+
+/* This file implements a serial console.
+ * We use a 9600 8N1 serial port */
+
+namespace Ion {
+namespace Console {
+
+void writeLine(const char * line) {
+  while (*line != NULL) {
+    Device::sendChar(*line++);
+  }
+  Device::sendChar('\r');
+  Device::sendChar('\n');
+}
+
+void readLine(char * line, int maxLineLength) {
+  if (maxLineLength <= 0) {
+    return;
+  }
+  char * cursor = line;
+  char * last = line+maxLineLength-1;
+  while (true) {
+    *cursor = Device::recvChar();
+    if (*cursor == '\r' || cursor == last) {
+      *cursor = 0;
+      return;
+    }
+    cursor++;
+  }
+}
+
+}
+}
+
+namespace Ion {
+namespace Console {
+namespace Device {
+
+void init() {
+  RCC.APB2ENR()->setUSART1EN(true);
+
+  GPIOB.MODER()->setMode(3, GPIO::MODER::Mode::AlternateFunction);
+  GPIOB.MODER()->setMode(6, GPIO::MODER::Mode::AlternateFunction);
+
+  GPIOB.AFR()->setAlternateFunction(3, GPIO::AFR::AlternateFunction::AF7);
+  GPIOB.AFR()->setAlternateFunction(6, GPIO::AFR::AlternateFunction::AF7);
+
+  UARTPort.CR1()->setUE(true);
+  UARTPort.CR1()->setTE(true);
+  UARTPort.CR1()->setRE(true);
+
+  // Set the Baud rate
+  // base clock = 16 MHz
+  // Baud rate = fAPB2/(16*USARTDIV)
+  // USARTDIV = 104.16667
+  //
+  // DIV_Fraction = 16*0.16666667
+  //  = 2.666667 -> 3
+  // DIV_Mantissa = 104 = 0x68
+  // USART_BRR = 0x683
+  UARTPort.BRR()->setDIV_FRAC(3);
+  UARTPort.BRR()->setDIV_MANTISSA(104);
+}
+
+char recvChar() {
+  while (UARTPort.SR()->getRXNE() == 0) {
+  }
+  return (char)UARTPort.DR()->get();
+}
+
+void sendChar(char c) {
+  while (UARTPort.SR()->getTXE() == 0) {
+  }
+  UARTPort.DR()->set(c);
+}
+
+}
+}
+}
diff --git a/ion/src/device/console.h b/ion/src/device/console.h
new file mode 100644
index 000000000..107fdf5ce
--- /dev/null
+++ b/ion/src/device/console.h
@@ -0,0 +1,31 @@
+#ifndef ION_DEVICE_CONSOLE_H
+#define ION_DEVICE_CONSOLE_H
+
+#include <ion/console.h>
+#include "regs/regs.h"
+
+namespace Ion {
+namespace Console {
+namespace Device {
+
+/*  Pin | Role              | Mode
+ * -----+-------------------+--------------------
+ * PC11 | UART1 RX          | Alternate Function
+ *  PD8 | UART1 TX          | Alternate Function
+ */
+
+void init();
+void shutdown();
+
+constexpr USART UARTPort = USART(1);
+constexpr static GPIOPin RxPin = GPIOPin(GPIOB, 14);
+constexpr static GPIOPin TxPin = GPIOPin(GPIOE, 9);
+
+void sendChar(char c);
+char recvChar();
+
+}
+}
+}
+
+#endif
diff --git a/ion/src/device/device.cpp b/ion/src/device/device.cpp
index c87a2c142..960c17302 100644
--- a/ion/src/device/device.cpp
+++ b/ion/src/device/device.cpp
@@ -10,6 +10,7 @@ extern "C" {
 #include "battery.h"
 #include "sd_card.h"
 #include "backlight.h"
+#include "console.h"
 
 #define USE_SD_CARD 0
 
@@ -61,6 +62,27 @@ void Ion::reset() {
   CM4.AIRCR()->requestReset();
 }
 
+static inline char hex(uint8_t d) {
+  if (d > 9) {
+    return 'A'+d;
+  }
+  return '0'+d;
+}
+
+const char * Ion::serialNumber() {
+  static char serialNumber[25] = {0};
+  if (serialNumber[0] == 0) {
+    uint8_t * rawUniqueID = (uint8_t *)0x1FFF7A10;
+    for (int i=0; i<24; i++) {
+      uint8_t d = *rawUniqueID++;
+      serialNumber[2*i] = hex(d & 0xF);
+      serialNumber[2*i+1] = hex(d >> 4);
+    }
+    serialNumber[24] = 0;
+  }
+  return serialNumber;
+}
+
 // Private Ion::Device methods
 
 namespace Ion {
@@ -101,6 +123,7 @@ void initPeripherals() {
 #if USE_SD_CARD
   SDCard::Device::init();
 #endif
+  Console::Device::init();
 }
 
 void shutdownPeripherals() {
diff --git a/ion/src/device/regs/rcc.h b/ion/src/device/regs/rcc.h
index 805b91341..561ba9f41 100644
--- a/ion/src/device/regs/rcc.h
+++ b/ion/src/device/regs/rcc.h
@@ -74,6 +74,7 @@ public:
   class APB1ENR : Register32 {
   public:
     REGS_BOOL_FIELD(TIM3EN, 1);
+    REGS_BOOL_FIELD(SPI3EN, 15);
     REGS_BOOL_FIELD(PWREN, 28);
   };
 
@@ -81,6 +82,7 @@ public:
   public:
     using Register32::Register32;
     REGS_BOOL_FIELD(TIM1EN, 0);
+    REGS_BOOL_FIELD(USART1EN, 4);
     REGS_BOOL_FIELD(ADC1EN, 8);
     REGS_BOOL_FIELD(SDIOEN, 11);
     REGS_BOOL_FIELD(SYSCFGEN, 14);
diff --git a/ion/src/device/regs/regs.h b/ion/src/device/regs/regs.h
index 9375e1ed7..3fe399ad0 100644
--- a/ion/src/device/regs/regs.h
+++ b/ion/src/device/regs/regs.h
@@ -13,7 +13,9 @@
 #include "rcc.h"
 #include "rng.h"
 #include "sdio.h"
+#include "spi.h"
 #include "syscfg.h"
 #include "tim.h"
+#include "usart.h"
 
 #endif
diff --git a/ion/src/device/regs/spi.h b/ion/src/device/regs/spi.h
new file mode 100644
index 000000000..a817a1371
--- /dev/null
+++ b/ion/src/device/regs/spi.h
@@ -0,0 +1,35 @@
+#ifndef REGS_SPI_H
+#define REGS_SPI_H
+
+#include "register.h"
+
+class SPI {
+public:
+  class CR1 : Register16 {
+  public:
+    REGS_BOOL_FIELD(SPE, 6);
+    REGS_BOOL_FIELD(LSBFIRST, 7);
+    REGS_BOOL_FIELD(SSI, 8);
+    REGS_BOOL_FIELD(SSM, 9);
+  };
+  class SR : Register16 {
+  public:
+    REGS_BOOL_FIELD(RXNE, 0);
+    REGS_BOOL_FIELD(TXE, 1);
+  };
+  class DR : public Register16 {
+  };
+
+  constexpr SPI(int i) : m_index(i) {}
+  constexpr operator int() const { return m_index; }
+  REGS_REGISTER_AT(CR1, 0x00);
+  REGS_REGISTER_AT(SR, 0x08);
+  REGS_REGISTER_AT(DR, 0x0C);
+private:
+  constexpr uint32_t Base() const {
+    return ((uint32_t []){0x40013000, 0x40003800, 0x40003C00})[m_index-1];
+  };
+  int m_index;
+};
+
+#endif
diff --git a/ion/src/device/regs/usart.h b/ion/src/device/regs/usart.h
new file mode 100644
index 000000000..cb454c2d6
--- /dev/null
+++ b/ion/src/device/regs/usart.h
@@ -0,0 +1,50 @@
+#ifndef REGS_USART_H
+#define REGS_USART_H
+
+#include "register.h"
+
+class USART {
+public:
+  class SR : Register32 {
+  public:
+    REGS_BOOL_FIELD(RXNE, 5);
+    REGS_BOOL_FIELD(TXE, 7);
+  };
+
+  class DR : Register32 {
+  public:
+    uint16_t get() volatile {
+      return (uint16_t)getBitRange(8, 0);
+    }
+    void set(uint16_t v) volatile {
+      setBitRange(8, 0, v);
+    }
+  };
+
+  class BRR : Register32 {
+  public:
+    REGS_FIELD(DIV_FRAC, uint8_t, 3, 0);
+    REGS_FIELD(DIV_MANTISSA, uint16_t, 15, 4);
+  };
+
+  class CR1 : Register32 {
+  public:
+    REGS_BOOL_FIELD(UE, 13);
+    REGS_BOOL_FIELD(TE, 3);
+    REGS_BOOL_FIELD(RE, 2);
+  };
+
+  constexpr USART(int i) : m_index(i) {}
+  constexpr operator int() const { return m_index; }
+  REGS_REGISTER_AT(SR, 0x00);
+  REGS_REGISTER_AT(DR, 0x04);
+  REGS_REGISTER_AT(BRR, 0x08);
+  REGS_REGISTER_AT(CR1, 0x0C);
+private:
+  constexpr uint32_t Base() const {
+    return ((uint32_t []){0x40011000, 0x40004400, 0x40004800})[m_index-1];
+  };
+  int m_index;
+};
+
+#endif