This is something I’ve been working about a month now. It’s a little handheld GPS / on board computer that shows altitude, current course, synced satellites, speed, time and date, distance between saved point and current point (and its course and corrdinates) and total trip distance.

Cube GPS Toy

At first I wanted a speed-o-meter for my bike but you know, coding it’s free and could stop adding functions.

I managed to get some cheap serial GPS receptor, a tiny OLED display and an Arduino Mini Pro and started to code. First I knew I would need some big font and so I made my own using paint, each character 24×32 (96bytes). This is the complete parts list:

• Ebay I2C SSD1306 based OLED display, 128×64, 0.96″ and 5V.
• Ebay Arduino Mini Pro (ATMEGA328p), 5V 16Mhz
• Sparkfun DC-DC step-up voltage converter (5V).
• Adafruit MPC73833 LiPo battery charger.
• Savaged iPod Nano 1st gen battery.
• Dealextreme EM-411 GPS 5V receiver.
• Savaged momentary buttons, resistors and wires.

I had to code some method to print own big fonts in the display and the moment I managed to control all the display functions as I wanted I started to code the methods to print GPS gathered data in the display. This is an earlier slowed display test that didn’t worked well:

The first prototype had just speed mode, was assembled with double tape and had no battery charger. It’s purpose was to see how speed meter worked testing it in my car.

First handheld GPS prototype

Then I dismantled firts prototype and assembled second prototype, this time no double tape, just boards soldered togheter. This is the schematic:

Tiny GPS schematic

And so I began building:

OLED Display up, GPS Conector (glued to DC-DC) down.

Second prototype assembling. Arduino Up, DC-DC down.

The actual prototype looks like a tiny packed devices cube with front display and momentary switches (best view on 720p). Here is a video with functions explanation:

I’m not a coder so code is pretty much ugly. Sketch it’s downloable from here. It uses TinyGPS library from Mikal Hart, custom new software serial to disable interrupts in pin ports and PinChangeInt, an Arduino library to handle buttons interrupts.

If you would like to contribute with functions or code fixes please feel free to contact me either in the comments or in my email address (at the bottom of the page).

For some time I’ve been thinking to use the iPhone 4 or the iPad as terminal serial console to configure routers or switches so after a little research I found this cable but a serial cable for $ 70 was not in my budget, so I opted for make my own cable (13 €).

iPad Serial to Cisco

Hardware

El iPad tiene un puerto serie escondido en el conector dock de todos los dispositivos móviles de Apple. Poniendo por ejemplo un iPhone o iPad con la pantalla hacia arriba, el pin 1 del conector Dock es el primero de la izquierda y el pin 30 el último:

The iPad has a serial port hidden in the dock connector of all Apple mobile devices. Putting some iPhone or iPad with the screen up, the Dock connector pin 1 is the first on the left and pin 30 the last:

• Pin 12: Serial TxD
• Pin 13: Serial RxD
• Pin 15/16 (either one, two or both): GND
• Pin 18: 3.3v

Se puede consultar todo el pinout aquí.

Pinout can be checked here.

Además del conexionado del puerto Dock es muy importante saber que este puerto serie funciona con 3.3v como un uno lógico mientras que los PCs/switches/routers buenos suelen funcionar a 12v como uno lógico. Si los conectasemos directamente iPad y Cisco seguramente quemariamos el puerto serie del iPad pero eso se soluciona con un conversor de voltajes que nos convierta los unos de 12v a 3.3v y viceversa.

In addition to the Dock port connection is very important to know that this serial port operates as a logic ‘one’ 3.3v while PCs / switches / routers typically operate at 12v as ‘one’ logical. If the iPad and Cisco directly conectasemos surely burn up the serial port of the iPad but that is solved with a voltage converter to convert us about 12v to 3.3v vice versa.

Standard 30 Pin Dock Connector

Sabiendo esto es cuestión de comprar un conversor de voltajes y un conector Dock para cablearlos entre sí adecuadamente usando el pinout que conocemos y así obtendremos nuestro cable para poder conectar un iPhone o un iPad a un puerto serie de Cisco y compatibles (HP, 3Com, etc.) por menos de 13€.

Knowing this is a matter of buying a voltage converter and a dock connector to wire them together properly using the pinout we know and so we get our cable to connect an iPhone or iPad to a serial port and compatible Cisco (HP, 3Com, etc..) for less than 13 €. They can be found by searching ‘ipod dock connector’ and ‘rs232 ttl converter’ on ebay.

Connected Serial Cable iPad/iPhone

Finished Serial Cable iPad/iPhone

Software

A partir de aqui se requiere un iPad o iPhone jailbreakeados y con acceso al sistema de archivos. En el iPad utilizo OpenSSH como servidor para obtener una shell e iSSH para conectarme por loopback a OpenSSH; de esta manera tenemos un terminal unix.

From here a jailbroken iPad or iPhone is required to access to the file system. In the iPad I use OpenSSH as server to be able to get a shell and, to connect to loopback, I use iSSH or Prompt.

Por último hay que instalar desde Cydia minicom, que es una aplicación de consola para abrir comunicaciones por el puerto serie de tipo terminal, y configurarlo como sigue:

Finally minicom has to be installed from Cydia, which is a console application to open the serial port communications terminal type, and set it as follows:

• Serial Device: /dev/tty.iap
• Bps/Par/Bits: 9600 8/N/1
• Hardware Flow Control: No
• Software Flow Control: No

Minicom Configuration iPad/iPhone

y con esto ya tendríamos terminado nuestro terminal serie con el iPad.

and with this we would have finished our series terminal with the iPad.

Preapertura Algecampus 2010

Este año somos solo dos personas (Galidor y yo) por lo que no damos a basto con las tareas por realizar como hacer la configuración y despliegue de switches, configurar el switch principal, el servidor DHCPd, DNS caché y monitorización y de vez en cuando alguna asistencia.

Graficas de monitorización Algecampus 2010

Dejo aqui la descarga: Arduino etherShield 8 relay

Pues ya he encontrado mi MOT (Microwave Oven Transformer). El domingo en el rastro alguien se dejó un horno microondas del 97 por ahí tirado así que lo entre un amigo y yo lo cogimos y los llevamos a casa, en donde se convirtió en carne de destornillador: extrajimos el transformador (220V -> 2500V), los cables de potencia, el condensador a juego con el voltaje y el ventilador.

El MOT por cierto pesa 7Kg el solo. Aun me tiemblan los brazos de haber cargado con todo el microondas por la calle.

El resto reposa para siempre en el contendor esperando a convertirse en carne de chatarrero.