Dec 182016
 
Orange Pi Zero - I/O

I finally figured out how to do simple I/O on the GPIO pins on the Orange Pi Zero. It’s actually the same as Raspberry Pi and it relies on /sys/class/gpio/

Most important: Use Armbian, and I in particular use 3.4.113 (legacy).

GPIO

 

Linux GPIO SOC Label CON4 CON4 Label SOC Linux GPIO
Vcc3V3-EXT 1 2 DCIN-5V
12 PA12 TWI0-SDA 3 4 DCIN-5V
11 PA11 TWI0-SCK 5 6 GND
6 PA6 PWM1 7 8 UART1_TX PG6 198
GND 9 10 UART1_RX PG7 199
1 PA1 UART2_RX 11 12 PA7 PA7 7
0 PA0 UART2_TX 13 14 GND
3 PA3 UART2_CTS 15 16 TWI1-SDA PA19  19
VCC3V3-EXT 17 18 TWI1-SCK PA18 18
15 PA15 SPI1_MOSI 19 20 GND
16 PA16 SPI1_MISO 21 22 UART2_RTS PA2 2
14 PA14 SPI1_CLK 23 24 SPI1_CS PA13 13
GND 25 26 PA10 PA10?

Note: PA10 does not seem to work.

 

To enable one GPIO pin, do this as root:

echo 7 >/sys/class/gpio/export
chmod a+rw /sys/class/gpio/gpio7/*

Now in NodeJS you can do (as non-root):

var Gpio = require('onoff').Gpio, 
  led = new Gpio(7, 'out'); 
 
function blinkled7() { 
  var state=false; 
  return function () { 
    console.log(state); 
    if (state) led.writeSync(0) 
    else led.writeSync(1); 
    state = ! state; 
    } 
} 
 
f=blinkled7(); 
setInterval(f, 1000);

which blinks GPIO pin 7 (AKA PA7). You can also watch pins:

var Gpio = require('onoff').Gpio,
  led = new Gpio(7, 'out'),
  button = new Gpio(16, 'in', 'both');

button.watch(function (err, value) {
  if (err) {
    throw err;
  }
  console.log("Changing to ", value);
  led.writeSync(value);
});

process.on('SIGINT', function () {
  console.log("Leaving...");
  led.unexport();
  button.unexport();
});

which makes the LED match what PA16 is. If you connect PA16 to e.g. PA6, you can change PA6, which is detected by PA16 which is reflected in the LED change on PA7!

 

LED’s

The 2 on-board LED’s can be controlled via

echo [0|1] > /sys/class/leds/[red|green]_led/brightness

which map to PA17 (red) and PL10 (green), but those are (of course) claimed by the LED driver.

PWM

Not figured out yet.

 

Dec 182016
 

Letzte Woche gab’s Vanillekipferl. Hier das Rezept (http://www.chefkoch.de/rezepte/403911129675192/Uromas-Vanillekipferl.html). Auf die Hälfte reduziert:

  • 150g Mehl
  • 125g Butter
  • 60g Mandeln, gemahlen
  • 50g Zucker
  • Vanillezucker/Vanillearoma
  • Zum Wenden: Puderzucker, Vanillezucker

Alles mischen, in Folie gewickelt 30min in den Kühlschrank stellen. In der Zwischenzeit Puderzucker und Vanillezucker mischen und in eine verschliessbare Schüssel geben (zum wiederverwenden des Zuckers).

Kipferlteig in eine Rolle mit etwa 4cm Durchmesser rollen. 1cm Scheiben abschneiden. Daraus die Kipferl formen und recht eng aneinander auf ein mit Backpapier belegtem Blech legen. Bei 175°C ca. 20 Minuten backen.

Kurz (3 min) kühlen lassen und dann in die Puderzucker-Zucker Mischung wenden. Abkühlen lassen und in eine Dose verschliessen.