Difference between revisions of "Alpha Clock Firmware v1"

Revision as of 03:52, 29 October 2012

The Alpha Clock Five is an alarm clock and alphanumeric LED display development platform based on the ATmega644A AVR microcontroller. It can be programmed through an AVR ISP programmer, using standard AVR-GCC techniques, or through an FTDI USB-TTL interface, using a modified version of the Arduino development environment.

Bootloader (Arduino style) programming

The microcontroller in Alpha Clock Five kit comes preprogrammed with the Sanguino Bootloader. Because of this, Alpha Clock Five can be reprogrammed right in the Arduino environment, through a USB-TTL interface such as the FTDI USB-TTL cable or the http://evilmadscience.com/productsmenu/accessories/210 Adafruit FTDI Friend].

The bootloader itself can only be written (or rewritten) with an AVR ISP programmer, such as the USBtinyISP. While most users will not ever need to do this, see below (under AVR ISP Programming) if you should need to do so.

Setting up the environment

Alpha Clock Five requires a rather specialized programming environment, that uses some older software versions and will be updated in the near future.

Required software:

• Arduino 0023 (available here), an older version of the Arduino development environment.
• Sanguino version 0023r2.zip from here. (This is an updated version of the Sanguino extensions to Arduino, by Ryan M Sutton.)

Install the Arduino program on your computer. The Sanguino extensions need to be installed separately, and the method for that depend, very slightly, on your operating system:

Installing Sanguino: Mac

First unzip the Sanguino-0023r2.zip file, which reveals a folder called "Sanguino." Then, find the location where you need to install it.

• Locate your Arduino.app file, version 0023 (which you may have just installed).
• Ctrl-click the file to show the contextual pop-up menu.
• From that menu, select "Show Package Contents."
• Within the resulting directory (Arduino.app), navigate to the folder Contents > Resources > Java > hardware
• Inside "hardware" there several folders, including one called "arduino." Copy the whole "Sanguino" folder, which you unzipped earlier into the hardware folder, next to "arduino."
• Restart Arduino.

If the Sanguino software is installed correctly, you will see Sanguino options in your Tools>Board menu.

Installing Sanguino: Windows

First unzip the Sanguino-0023r2.zip file, which reveals a folder called "Sanguino." Then, copy that to within your Arduino application.

• Locate your Arduino application
• Copy /Sanguino to arduino-0023/hardware/
• You should end up with arduino-0023/hardware/Sanguino/
• Restart Arduino.

If the Sanguino software is installed correctly, you will see Sanguino options in your Tools>Board menu.

Installing Sanguino: Linux

First unzip the Sanguino-0023r2.zip file, which reveals a folder called "Sanguino." Then, copy that to within your Arduino application.

• Locate your Arduino application
• Copy ~/Sanguino to arduino-0023/hardware/
• You should end up with arduino-0023/hardware/Sanguino/

• Restart Arduino.

If the Sanguino software is installed correctly, you will see Sanguino options in your Tools>Board menu.

Uploading firmware

Connect your FTDI interface (e.g., USB-TTL cable) to location J2 on the circuit board (the 6-pin SIL right-angle header also labeled "LOGIC-LEVEL (TTL) SERIAL"), watching the polarity. For one of the cables with rainbow-wires on the end, black goes down, green goes up.

Make sure that the correct serial port is selected in the Tools>Serial Port menu.

Select "Sanguino W/ ATmega644P" from your Tools>Board menu

Make sure that Alpha Clock Five is powered on.

Click the "Upload" button in your Arduino window to upload the sketch.

Programming the bootloader

Most users will not need to reprogram the bootloader at any point.

Programming the bootloader onto a new ATmega644A requires an AVR ISP programmer (see more about that below). This can be done directly from within the Arduino environment (using the Tools>Burn bootloader option), but is complicated by the fact that we are using an ATmega644A rather than the ATmega644P normally expected by Sanguino.

First, download and install this alternate version (130 kB .zip file) of the Sanguino software, which includes a definition of the 644A for purposes of using the bootloader.

Then, to install the bootloader:

• Select as your board type (from Tools>Board), "Sanguino W/ ATmega644/644A"
• From Tools>Burn Bootloader, select your AVR ISP programmer type, to actually burn the bootloader

After installing the bootloader, select board type "Sanguino W/ ATmega644P" when you wish to reprogram the board through the bootloader, as the "software" device signatures returned by the bootloader are those for the '644P. If you reprogram the board through an ISP programmer (including reburning of the bootloader), you will still need to select ATmega644A as the device type.

Technical note on device signature

The device signature that the Alpha Clock's bootloader returns is that of the ATmega644P (not the ATmega644A). This is intentional. It is (1) code compatible and (2) better supported under both AVR-GCC and the Arduino/Sanguino environments. There are longstanding bugs in support for the 644A, and this is a stable and sane workaround.

The "hardware" device signatures-- those that you will read if you try to reprogram the AVR through an ISP interface --do remain those of the ATmega644A.

AVR ISP Programming

The Alpha Clock Five PCB features a 6-pin AVR ISP connector (J4), which can be used to program the microcontroller through any suitable AVR ISP programmer. We recommend the Adafruit USBtinyISP programmer for most purposes. The Alpha Clock Five should be powered separately from 5 V while programming; Alpha Clock Five requires more power than can usually be safely provided by USB.

The circuit can be programmed through AVR-GCC or any other AVR software environment, including AVR Studio. If using AVR-GCC, you may find it helpful to target (set the MCU type as) the ATmega644P rather than the ATmega644A, as it is better supported.

Please refer to the schematics (PDF) for pinouts and electrical features of the Alpha Clock Five.

Standard Firmware

Version 1.0

Version 1.0 of the Alpha Clock Five firmware is available here (49 kB .pde file).

Besides the Arduino 0023/Sanguino-0023r2 environment described earlier, this code requires that you install the "old" DateTime library (really, both the DateTime and DateTimeStrings libraries that are included with the download) , available here. These should be installed like regular Arduino libraries, within the "libraries" directory of your sketch folder.

Planned future versions

A future version of the Alpha Clock Five firmware is planned, which will-- as its major change --use a more up-to-date software environment. Planned improvements include the use of Arduino 1.0, updated Sanguino components, the new Arduino Time library, and compatibility with updated versions of the serial and I2C libraries within Arduino.

Planned future features include:

• Additional display modes
• Expanded serial communication, with additional commands
• Expanded serial communication, using the second serial port for daisy-chained displays

If you would like to suggest additional features, please use the talk page or the Evil Mad Scientist Forums.

Code contributions and are welcome, of course, and we will be setting up a formal repository in the near future. In the mean time, please contact Evil Mad Scientist Laboratories if you are interested in contributing.

Alternate "Demo" firmware

A simple demo program, which shows displaying text on the LED display, playing sounds, lighting up the rear-panel nightlight, and recognizing button events is available for download here (15 kB .pde file).