Arduino Yún, Part 2

OK, I have had my Yún for 3 days now, so let’s get started.

First of all, pictures:

Yun_top_1

Yun_top_2

Yun_top_3

The heart of the Arduino core: the Atmel MEGA32U4 microcontroller. 32KB of Flash memory, 2,5KB of SRAM and 1KB of EEPROM, the usual I/O, essentially a Leonardo. Pretty classic stuff.
MEGA32U4

What is not visible in the pictures, is this:
Atheros_AR9331_2This is the Atheros AR9331 processor. It runs at 400MHz, has 16MB of Flash, 64MB of RAM and runs Linino, a Linux distribution based on OpenWRT.

Yun_bottom_1

Yun_bottom_2

Yun_bottom_3

Now, with 3 different reset switches! From left to right, for the Yun (Linux), the WiFi and the 32U4 (Arduino).
Reset_Buttons

I was wandering how fast “upload a sketch over WiFi” was, so I made a little video comparing it to the classic “upload over USB”:

Arduino Yún

arduino-yun-designboom01[1]

Now, this is interesting. An Arduino that has an on-board processor that runs Linux and supports Ethernet and WiFi.

It is essentially a Leonardo with an Atheros AR9331 running Linino, an OpenWRT distribution.

They talk to each other through what is called a Bridge library. There is also an official Guide that looks very comprehensive.

YunParts[1]

A lovely feature is Arduino programming over WiFi! 🙂

Naturally, I ordered one as soon as it became available (that is, today!) and should have it in a few days.

Stay tuned..

Buffalo Shield v.1.1 for TFT HiFiDuino

Following my previous post on TFT HiFiDuino v.1.00, this is what you need to know in order to build my Buffalo Shield.

First of all, here are the DipTrace files (schematic & PCB): Buffalo Shield v.1.1 for TFT HiFiDuino (schematic & PCB) (11429 downloads )

And here is the relevant build & wire guide: Buffalo Shield v.1.1g for TFT HiFiDuino (documentation) (7809 downloads )

This is what DipTrace thinks the board ought to look like:
Arduino_Shield_1.1_Render_07_c

And this is what it actually looks like:
Arduino_Shield_v.1.1_1_800x872

Close enough..

This shield features:
– Galvanic isolation for the I2C signals as well as 2 digital outputs (Arduino -> Buffalo) and 1 digital input (Buffalo -> Arduino).
– EEPROM chip (24LC256) either in SMT or DIP footprint.
– Backlight control for the TFT through a PWM-controlled transistor.
– Headers for two rotary encoders.
– Output for power relay (for remote on/off).
– Header for IR receiver.

This is the schematic for the shield:
Arduino_Shield_Schematic-0.91

And this is the resulting PCB:
Arduino_Shield_PCB_v1.1b

This is a description of the various headers:

IR: Use a standard 38KHz IR Receiver Module, like the TSOP4838.
1: Signal (Pin 9)
2: GND
3: 3.3V

RotaryEncoder1: Use any simple rotary encoder.
1: Left pin (Pin 7)
2: Right pin (Pin 6)
3: Selector pin 1 (Pin 5)
4: Middle Pin & Selector pin 2 (GND)

RotaryEncoder2: Use any simple rotary encoder.
1: Left pin (Pin A3)
2: Right pin (Pin A4)
3: Selector pin 1 (Pin A3)
4: Middle Pin & Selector pin 2 (GND)

I2C_In:
1: SDA
2: SCL
(note: this is the I2C connection to the Arduino. SDA should be connected to pin 20 and SCL to pin 21)

I2C_Bypass:
1: GND
2: SDA
3: SCL
(use this if / when an isolator IC (U2) is not used to send the I2C signal to the Buffalo)

Isolated_Outs:
1: Out 1 (Pin A2)
2: Out 2 (Pin A7)

TFT_power:
1: TFT Backlight LED (dimmed by Pin 8)
2, 3: 3.3V (for TFT power & pin RD)
4: GND

PowerInput:
1: GND
2: Vin (8V-12V)
(connect here the power supply to the Arduino)

PowerRelay:
1: GND
2: 3.3V out (Pin A0) in case of Due, 5V in case of MEGA
(connect here the power relay that powers on the DAC)

To_Buffalo:
1: Buffalo Vcc (3.3V)
2: SDA
3: Sidecar Control (Pin 3)
4: Lock LED input (Pin A1)
5: SCL
6: Buffalo GND