This document discusses using JavaScript for embedded programming on microcontrollers. It introduces Espruino, which allows programming microcontrollers using JavaScript. Espruino provides inexpensive hardware with peripherals and libraries, making it suitable for hobbyists and prototyping. In contrast to Arduino, Espruino includes a debugger. The document demonstrates examples of using Espruino to read temperature and humidity sensors and expose sensor data over Bluetooth Low Energy. It encourages exploring Espruino and related projects like Tessel and Neonious for embedded JavaScript development.

1. Embedded JavaScript
Mikrocontroller programmieren… mit JavaScript?!
Jens Siebert (@jens_siebert)
WebMontag Kassel, 11. Juni 2018
https://www.slideshare.net/JensSiebert1

2. Mikrocontroller

3. Embedded Programmierung bisher…

4. Embedded Programmierung bisher…

5. Embedded Programmierung bisher…
#define XTAL (12000000UL) /* Oscillator frequency */
#define OSC_CLK ( XTAL) /* Main oscillator frequency */
#define RTC_CLK ( 32000UL) /* RTC oscillator frequency */
#define IRC_OSC ( 4000000UL) /* Internal RC oscillator
frequency */
/* F_cco0 = (2 * M * F_in) / N */
#define __M (((PLL0CFG_Val ) & 0x7FFF) + 1)
#define __N (((PLL0CFG_Val >> 16) & 0x00FF) + 1)
#define __FCCO(__F_IN) ((2ULL * __M * __F_IN) / __N)
#define __CCLK_DIV (((CCLKCFG_Val ) & 0x00FF) + 1)
/* Determine core clock frequency according to settings */
#if (PLL0_SETUP)
#if ((CLKSRCSEL_Val & 0x03) == 1)
#define __CORE_CLK (__FCCO(OSC_CLK) / __CCLK_DIV)
#elif ((CLKSRCSEL_Val & 0x03) == 2)
#define __CORE_CLK (__FCCO(RTC_CLK) / __CCLK_DIV)
#else
#define __CORE_CLK (__FCCO(IRC_OSC) / __CCLK_DIV)
#endif
#else
#if ((CLKSRCSEL_Val & 0x03) == 1)
#define __CORE_CLK (OSC_CLK / __CCLK_DIV)
#elif ((CLKSRCSEL_Val & 0x03) == 2)
#define __CORE_CLK (RTC_CLK / __CCLK_DIV)
#else
#define __CORE_CLK (IRC_OSC / __CCLK_DIV)
#endif
#endif
uint32_t SystemCoreClock = __CORE_CLK;/*!< System Clock Frequency (Core Clock)*/
void SystemCoreClockUpdate (void) /* Get Core Clock Frequency */
{
/* Determine clock frequency according to clock register values */
if (((LPC_SC->PLL0STAT >> 24) & 3) == 3) { /* If PLL0 enabled and connected */
switch (LPC_SC->CLKSRCSEL & 0x03) {
case 0: /* Int. RC oscillator => PLL0 */
case 3: /* Reserved, default to Int. RC */
SystemCoreClock = (IRC_OSC *
((2ULL * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
(((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1) /
((LPC_SC->CCLKCFG & 0xFF)+ 1));
break;
case 1: /* Main oscillator => PLL0 */
SystemCoreClock = (OSC_CLK *
((2ULL * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
(((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1) /
((LPC_SC->CCLKCFG & 0xFF)+ 1));
break;
case 2: /* RTC oscillator => PLL0 */
SystemCoreClock = (RTC_CLK *
((2ULL * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
(((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1) /
((LPC_SC->CCLKCFG & 0xFF)+ 1));
break;
}
}
else {
switch (LPC_SC->CLKSRCSEL & 0x03) {
case 0: /* Int. RC oscillator => PLL0 */
case 3: /* Reserved, default to Int. RC */
SystemCoreClock = IRC_OSC / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
break;
case 1: /* Main oscillator => PLL0 */
SystemCoreClock = OSC_CLK / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
break;
case 2: /* RTC oscillator => PLL0 */
SystemCoreClock = RTC_CLK / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
break;
}
}
}

6. Embedded Programmierung bisher…
#include <stdint.h>
#include "LPC17xx.h“
#define CLOCK_SETUP 1
#define SCS_Val 0x00000020
#define CLKSRCSEL_Val 0x00000001
#define PLL0_SETUP 1
#ifdef MCB1700
# define PLL0CFG_Val 0x00050063
# define PLL1_SETUP 1
# define PLL1CFG_Val 0x00000023
# define CCLKCFG_Val 0x00000003
# define USBCLKCFG_Val 0x00000000
#else
# define PLL0CFG_Val 0x0000000B
# define PLL1_SETUP 0
# define PLL1CFG_Val 0x00000000
# define CCLKCFG_Val 0x00000002
# define USBCLKCFG_Val 0x00000005
#endif
#define PCLKSEL0_Val 0x00000000
#define PCLKSEL1_Val 0x00000000
#define PCONP_Val 0x042887DE
#define CLKOUTCFG_Val 0x00000000
#define FLASH_SETUP 1
#define FLASHCFG_Val 0x0000303A
#define CHECK_RANGE(val, min, max) ((val < min) || (val > max))
#define CHECK_RSVD(val, mask) (val & mask)
if (CHECK_RSVD((SCS_Val), ~0x00000030))
#error "SCS: Invalid values of reserved bits!"
#endif
#if (CHECK_RANGE((CLKSRCSEL_Val), 0, 2))
#error "CLKSRCSEL: Value out of range!"
#endif
#if (CHECK_RSVD((PLL0CFG_Val), ~0x00FF7FFF))
#error "PLL0CFG: Invalid values of reserved bits!"
#endif
#if (CHECK_RSVD((PLL1CFG_Val), ~0x0000007F))
#error "PLL1CFG: Invalid values of reserved bits!"
#endif
#if (PLL0_SETUP) /* if PLL0 is used */
#if (CCLKCFG_Val < 2) /* CCLKSEL must be greater then 1 */
#error "CCLKCFG: CCLKSEL must be greater then 1 if PLL0 is used!"
#endif
#endif
#if (CHECK_RANGE((CCLKCFG_Val), 2, 255))
#error "CCLKCFG: Value out of range!"
#endif
#if (CHECK_RSVD((USBCLKCFG_Val), ~0x0000000F))
#error "USBCLKCFG: Invalid values of reserved bits!"
#endif
#if (CHECK_RSVD((PCLKSEL0_Val), 0x000C0C00))
#error "PCLKSEL0: Invalid values of reserved bits!"
#endif
#if (CHECK_RSVD((PCLKSEL1_Val), 0x03000300))
#error "PCLKSEL1: Invalid values of reserved bits!"
#endif
#if (CHECK_RSVD((PCONP_Val), 0x10100821))
#error "PCONP: Invalid values of reserved bits!"
#endif
#if (CHECK_RSVD((CLKOUTCFG_Val), ~0x000001FF))
#error "CLKOUTCFG: Invalid values of reserved bits!"
#endif
/* Flash Accelerator Configuration ------------------------*/
#if (CHECK_RSVD((FLASHCFG_Val), ~0x0000F07F))
#error "FLASHCFG: Invalid values of reserved bits!"
#endif

7. Embedded Programmierung bisher…
void SystemInit (void)
{
#if (CLOCK_SETUP) /* Clock Setup */
LPC_SC->SCS = SCS_Val;
if (LPC_SC->SCS & (1 << 5)) { /* If Main Oscillator is enabled */
while ((LPC_SC->SCS & (1<<6)) == 0);/* Wait for Oscillator to be ready */
}
LPC_SC->CCLKCFG = CCLKCFG_Val; /* Setup Clock Divider */
/* Periphral clock must be selected before PLL0 enabling and connecting
* - according errata.lpc1768-16.March.2010 -
*/
LPC_SC->PCLKSEL0 = PCLKSEL0_Val; /* Peripheral Clock Selection */
LPC_SC->PCLKSEL1 = PCLKSEL1_Val;
#if (PLL0_SETUP)
LPC_SC->CLKSRCSEL = CLKSRCSEL_Val; /* Select Clock Source for PLL0 */
LPC_SC->PLL0CFG = PLL0CFG_Val; /* configure PLL0 */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
LPC_SC->PLL0CON = 0x01; /* PLL0 Enable */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
while (!(LPC_SC->PLL0STAT & (1<<26)));/* Wait for PLOCK0 */
LPC_SC->PLL0CON = 0x03; /* PLL0 Enable & Connect */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
while (!(LPC_SC->PLL0STAT & ((1<<25) | (1<<24))));/* Wait for PLLC0_STAT & PLLE0_STAT */
#endif
#if (PLL1_SETUP)
LPC_SC->PLL1CFG = PLL1CFG_Val;
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
LPC_SC->PLL1CON = 0x01; /* PLL1 Enable */
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
while (!(LPC_SC->PLL1STAT & (1<<10)));/* Wait for PLOCK1 */
LPC_SC->PLL1CON = 0x03; /* PLL1 Enable & Connect */
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
while (!(LPC_SC->PLL1STAT & ((1<< 9) | (1<< 8))));/* Wait for PLLC1_STAT & PLLE1_STAT */
#else
LPC_SC->USBCLKCFG = USBCLKCFG_Val; /* Setup USB Clock Divider */
#endif
LPC_SC->PCONP = PCONP_Val; /* Power Control for Peripherals */
LPC_SC->CLKOUTCFG = CLKOUTCFG_Val; /* Clock Output Configuration */
#endif
#if (FLASH_SETUP == 1) /* Flash Accelerator Setup */
LPC_SC->FLASHCFG = (LPC_SC->FLASHCFG & ~0x0000F000) | FLASHCFG_Val;
#endif
}

8. Embedded Programmierung bisher…
- Volle Kontrolle über Hardware
- Teure (Entwicklungs-)Hardware
- Spezialwissen
- Für Hobbyanwender kaum geeignet

9. Die Revolution: Arduino!

10. Die Revolution: Arduino!
- Preiswerte Hardware
- Viel (preiswerte) Peripherie inkl. Bibliotheken verfügbar
- Für Hobbyanwender/Quereinsteiger/Rapid Prototyping gut geeignet
- Kein Debugger 

11. Und JavaScript?

12. Espruino

13. Espruino
- Preiswerte Hardware
- Viel (preiswerte) Peripherie inkl.
Bibliotheken verfügbar
- Für Hobbyanwender/Quereinsteiger/Rapid
Prototyping gut geeignet
- Debugger verfügbar 

14. Demo Time!

15. Beispiel: Temperatur
function onTimer() {
// Messwert vom Temperatursensor auslesen
var t = E.getTemperature().toFixed(1);
// Backbuffer loeschen
g.clear();
// Kleine Schriftart für die Titelzeile auswaehlen
g.setFontBitmap();
// Titelzeile zeichnen
g.drawString("Temperature:");
// Grosse Schriftart für den Messwert auswaehlen
g.setFontVector(40);
// Messwert zentriert zeichnen, 10px Abstand vom oberen Rand
g.drawString(t, (g.getWidth() - g.stringWidth(t))/2, 10);
// Backbuffer auf Display darstellen
g.flip();
}
// Messwert und Display-Inhalt alle zwei Sekunden aktualisieren
setInterval(onTimer,2000);
// Initiale Darstellung des Messwertes
onTimer();

16. Beispiel: Luftfeuchtigkeit
// I2C-Schnittstelle konfigurieren
I2C1.setup( {scl: A5, sda: A4 } );
// HTU21D-Modul laden und über I2C-Schnittstelle verbinden
var htu = require('HTU21D').connect( I2C1 );
function onTimer() {
// Messwert vom Luftfeuchtesensor auslesen
var t = htu.readHumidity().toFixed(1);
// Backbuffer loeschen
g.clear();
// Kleine Schriftart für die Titelzeile auswaehlen
g.setFontBitmap();
// Titelzeile zeichnen
g.drawString("Humidity:");
// Grosse Schriftart für den Messwert auswaehlen
g.setFontVector(40);
// Messwert zentriert zeichnen, 10px Abstand vom oberen Rand
g.drawString(t, (g.getWidth() - g.stringWidth(t))/2, 10);
// Backbuffer auf Display darstellen
g.flip();
}
// Messwert und Display-Inhalt alle zwei Sekunden aktualisieren
setInterval(onTimer,2000);
// Initiale Darstellung des Messwertes
onTimer();

17. Beispiel: Bluetooth LE
// I2C-Schnittstelle konfigurieren
I2C1.setup( {scl: A5, sda: A4 } );
// HTU21D-Modul laden und über I2C-Schnittstelle verbinden
var htu = require('HTU21D').connect( I2C1 );
// Verfuegbare BLE Services und Charakteristiken bekannt machen
NRF.setServices({
// Envrionmental Sensing Service konfigurieren
0x181A: {
// Temperatur Charakteristik konfigurieren
0x2A6E: {
readable: true,
notify: true,
writeable: false,
value: new Int16Array([E.getTemperature() * 100]).buffer
},
// Luftfeuchte Charakteristik konfigurieren
0x2A6F: {
readable: true,
notify: true,
writeable: false,
value: new Uint16Array([htu.readHumidity() * 100]).buffer
}
}
// Envrionmental Sensing Service bekannt machen
}, {advertise: ['0x181A']});
// Messwerte erfassen und Benachrichtigungen versenden
function onTimer() {
NRF.updateServices({
// Envrionmental Sensing Service aktualisieren
0x181A: {
// Temperatur Charakteristik aktualisieren
0x2A6E: {
value: new Int16Array([E.getTemperature() * 100]).buffer,
notify: true
},
// Luftfeuchte Charakteristik aktualisieren
0x2A6F: {
value: new Uint16Array([htu.readHumidity() * 100]).buffer,
notify: true
}
}
});
}
NRF.on('connect', function(addr) {
// Messwert aktualisieren und uebermitteln
setInterval(onTimer, 2000);
// Initiale Uebermittlung des Messwertes
onTimer();
});

18. Beispiel: Bluetooth LE

19. Literatur

20. Vielen Dank!
https://www.espruino.com
https://www.espruino.com/Pixl.js
Tessel: https://www.tessel.io
Neonious: https://www.neonious.com
Slides: https://www.slideshare.net/JensSiebert1
Twitter: @jens_siebert