IM-ME Screen Reverse Engineered

February 1, 2010 by Mike Szczys 3 Comments

[Dave] figured out the command set for the IM-ME terminal. It took a bit of sleuthing to get this pink plastic peripheral to give up these secrets. He used an oscilloscope to sniff out the SPI connections, then used a hacked IM-ME to capture the traffic from a factory-fresh unit. He managed to extrapolate how write data was being sent but he still couldn’t figure out how commands were differentiated from that data. With the info at hand he searched around the interwebs to find that the screen uses an ST7565S controller. Now he’s got custom firmware to make the LCD display do his bidding and we’re wondering what’s next?

Modular Systems Using SPI

December 22, 2009 by Mike Szczys 5 Comments

[Humberto] is at it again with a NerdKits video detailing the use of an SPI bus to communicate between microcontrollers. He started with a previous LED marquee project which was limited to a 5×24 LED Matrix and developed a modular solution to increase the size limitation.

The writeup and video embedded after the break do a great job of detailing the important differences between a stand-alone and a modular system. The good news is that the ATmega168 chips being used have a built-in interrupt based SPI protocol. Once wired correctly, a master control chip addresses each module separately, adding data to their buffer until a full frame has been transferred, then moves onto the next module.

Some of the caveats to this system such as digital transmission over long distances are discussed. We do wonder about power limitations if all LED’s in the marquee are illuminated at once. But that concern aside, if you’re thinking of playing around with an LED display don’t forget that there’s usually a huge price break for orders of 500 or 1000 LEDs!

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Parts: Unboxing The Bus Pirate

July 20, 2009 by Ian 43 Comments

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For months we’ve used our Bus Pirate universal serial interface tool to demonstrate electronics parts, so it’s only appropriate that the Bus Pirate get it’s own parts post. We recently had a Bus Pirate preorder, and today we received the pre-production Bus Pirate prototype from Seeed Studio. This prototype was mailed just a few days before preorder 1 started to ship, so those packages should start arriving any day.

Follow along as we unbox the prototype Bus Pirate, and connect it to a debugger to determine the PIC24FJ64GA002-I/SO revision that shipped with this board. Use this post to share your own Bus Pirate unboxing experience. Pictures and discussion after the break.

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Parts: SPI EEPROM (25AA/25LC)

June 30, 2009 by Ian 11 Comments

3EEPROM-SPI

Microchip’s 25AA/25LC EEPROMs are data storage chips with a simple 3-wire interface. The 25AA/LC is an SPI version of the common 24AA/LC I2C EEPROM. It comes in capacities of 128bytes to 128kilobytes. We looked at the smallest, the 128byte 25AA010A.

There are Bus Pirate demonstrations for most types of serial EEPROMs. Check out our previous 1-wire (DS2431) and I2C (24LC1025) EEPROM posts.

Continue below to see our test circuit and a demonstration of the 25AA010 EEPROM. We used the Bus Pirate to play with this chip from our PC. For a limited time you can get your own Bus Pirate, fully assembled and shipped worldwide, for only $30.

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Parts: ShiftBrite RGB LED Module (A6281)

June 29, 2009 by Ian 11 Comments

shiftbriteii

Macetech’s ShiftBrite is a high-power RGB LED coupled with an Allegro A6281 backpack. The A6281 uses three 10bit pulse-width modulators to mix millions of colors using the red, green, and blue elements in the RGB LED. Multiple modules can be chained together for bigger projects, like the ShiftBrite table.

Below the break we demonstrate a ShiftBrite module using the Bus Pirate. For a limited time you can get your own Bus Pirate, fully assembled and shipped worldwide, for only $30.

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How-to: The Bus Pirate V2 With USB

June 25, 2009 by Ian 32 Comments

buspiratev2goii450

Update, Saturday July 4th, 2009: All preorders are closed.

The Bus Pirate is a universal serial interface tool, we use it to test new chips without writing any code. It currently supports most serial protocols, including 1-Wire, I2C, SPI, JTAG, asynchronous serial, MIDI, and more. We added some other features we frequently need, like pulse-width modulation, frequency measurement, voltage measurement, bus sniffers, pull-up resistors, and switchable 3.3volt and 5volt power supplies.

The new v2 family adds USB power and connectivity to the best Bus Pirate design yet. We also reduced the part count and cost wherever possible. If you want to get your hands on some Bus Pirate USB goodness, Seeed Studio has assembled hardware for $30 (including worldwide shipping).

Read about the new design after the break.

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Parts: Programmable Gain Amplifier (MCP6S26)

March 30, 2009 by Ian 12 Comments

mcp6s26

Microchip’s MCP6S21/2/6/8 are programmable gain amplifiers that multiply an input voltage by a factor of 1, 2, 4, 5, 8, 10, 16, and 32. The MCP6S22/6/8 also have selectable input channels for working with different signal sources. The multiplication factor and input channel are configured through an SPI interface. This chip is useful for multiplying a small input signal, and selecting among several analog input sources. We demonstrate the six channel MCP6S26 below.

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