Handy Cricket FAQ

How do you hook up an LCD to your Handy Cricket?

What is the difference between the Handy Board and Handy Cricket?

The Handy Board is based on the Motorola 68HC11 processor and includes 32K of battery-backed static RAM, a 16x2 LCD display, four DC motor outputs, 7 analog inputs, 9 digital inputs, and a built-in rechargable nicad battery. The Handy Board is programmable in the custom Interactive C language, assembly language, or any general-purpose programming tool for the HC11 processor.

The Handy Cricket is based on the Microchip PIC16C715 processor and includes 4096 bytes of user program/data memory, two DC motor outputs, two analog inputs, bidirectional infrared communications, a custom Cricket Bus expansion jack, and a 4-AA cell battery holder. The Handy Cricket is programmed with the custom Cricket Logo language, available both in text and iconic versions.

To compare them briefly, the Handy Board is substantially more powerful, but the Handy Cricket is much smaller, lighter, and less expensive. Also, the Handy Cricket's Expansion Bus gives it more capability than the 2-motor/2-sensor basic functionality.

(Last updated 2002-06-21)

What is the relationship between the Handy Cricket and the other Cricket projects I have heard about?

Fred Martin did a series of projects around the idea of “programmable bricks” when he was a student (and later, a member of the research staff) at MIT. He worked on a project by the name of Crickets there.

When Fred left that university, he licensed the work that went by the name of “Cricket” and is launching products here by the name of “Handy Cricket.”

(Last updated 2002-06-21)

Why are they called Crickets?

We wanted to emphasize our Crickets' ability to communicate with one another, and we were inspired by the image of a field of crickets chirping with one another.

(Last updated 2002-06-21)

Where did the Handy Cricket come from?

The Handy Cricket is based on ideas and technology developed in the Cricket project of the Lifelong Kindergarten group, headed by Mitchel Resnick, at the Media Laboratory at Massachusetts Institute of Technology (MIT). The core Cricket design was begun by Brian Silverman with Fred Martin in 1995. Since that time, Bakhtiar Mikhak and Robbie Berg have made significant contributions to the Cricket design. Rick Borovoy suggested the name “Cricket” and contributed to early conceptual work. The Cricket team has also benefited from the work of more than a dozen MIT undergraduate students.

(Last updated 2002-06-21)

Is the Handy Cricket system open-source like the Handy Board?

The Handy Cricket seems bigger than the MIT Cricket.

It's true—the Handy Cricket is bigger than the research Cricket. The reason is that the Handy Cricket runs off of four AA batteries, while the research Cricket used a 9v battery.

The 9v battery is a cool form factor, but in real-world use, the research Cricket burns through them pretty quickly. We're talking a battery life of under an hour in some applications. At $2 a pop for a 9v alkaline, that gets expensive fast.

So the Handy Cricket is built somewhat bigger, but with a battery system that can last ten times as long as the research version of the Cricket.

(Last updated 2002-06-21)

What are the dimensions of the Handy Cricket?

The board of the Handy Cricket measures 2-1/4” by 1-7/8” (5.7 by 4.8 cm). With the battery pack, the full dimensions are 2-1/2” by 2-1/4” (6.4 by 5.7 cm).

(Last updated 2002-06-21)

When will you be releasing a USB Interface Cricket?

Can you view your sensor readings on your Cricket?

Yes. You can run a short Logo statement that tells the Cricket to continuously transmit a sensor reading as a series of IR bytes. These bytes automatically show up in the Cricket Logo software's Cricket Monitor display.

For example, to see the readings on sensor A, type the following statement into the Cricket Logo Command Center:

loop [send sensora]

The values will then show up in the Cricket Monitor display (above the Download button).

The Cricket will transmit the sensor A values until you press its Run/Stop button or turn it off.

(Last updated 2002-06-21)

Can you program the Handy Cricket with NQC?

Can the Handy Cricket and the RCX communicate with each other?

No, the Handy Cricket and the RCX use fundamentally different IR technologies and can not communicate with one another. The Handy Cricket comes with its own Serial-IR interface, which is not compatible with the LEGO RCX IR Tower.

(Last updated 2002-06-21)

The Cricket won't beep when I type "beep" in the Command Center.

I want to read the Cricket's sensors from the serial port of my computer.

Here is one way to do it.

Using the Cricket Logo software, put the following program on the Cricket:

to reply
loop [
  waituntil [newir?]
  if ir = 1 [send sensora]
  if ir = 2 [send sensorb]
]
end

Put reply in the Run This line, download, and run the program.

Now, whenever the Cricket sees the value 1, it will reply with the value of sensora; if it sees 2, it will reply with sensorb.

From your program, set the serial line for 9600-N-8-1. Transmit a 1 (binary, NOT the ascii value) and read the reply. You'll first get the hardware echo from the serial interface (a 1, or whatever character you just sent) and then the answer from the Cricket.

(Last updated 2002-07-28)

Can I get the Cricket to automatically run its program when it is turned on?

Yes, you can do this. Firstly, load your program so that it will run when you press the Start button. (i.e., put the program you want to run in the "Run This" line.)

Then, when the Cricket is idle, type the following at the Command Center:

db $fff 0

Now power-cycle the Cricket. It will autostart your program.

(Last updated 2007-05-08)

Why are there two jacks per motor port?

There are two jacks per motor port so that you can easily reverse the direction that a motor is turning.

If you want a motor to turn in the opposite direction, you can unplug it, rotate the plug 180 degrees, and then re-plug it in the other jack.

You can also change the motor direction with the software commands thisway, thatway, and rd.

(Last updated 2002-12-01)

Can I power the Cricket with more than 6 volts?

What are the differences between the Handy Cricket and the MIT Crickets?

The Handy Cricket is most closely related to the MIT “Blue Dot” Cricket. Before explaining the differences, here's how they are the same. Both can run two motors and use two sensors. Their infrared communications are compatible. They have the same memory for user programs. Both have a pushbutton and a beeper.

Now, here are the differences:

• MIT Cricket uses a 9v battery. Handy Cricket uses four AA cells.

• Motor and sensor connectors are different.

• Bus device connector and voltage levels are different.

(Last updated 2003-02-18)

How can I make the Cricket stop automatically running its program?

To make the Cricket stop running its program automatically, first hold down the Run/Stop program when turning on the Cricket. This will prevent it from running your program, and it will be idle, so you can talk to it.

Then, enter the following at the Command Center:

db $fff $ff

Power-cycle the Cricket, and it should no longer automatically run its program.

(Last updated 2007-05-08)

What are good DC motors to use with the Cricket?

Can I use a DC adapter with the Cricket?

What kind of servo motors work with the Super Cricket?

What is a continuous rotation servo?

How do I install the Super Cricket libraries?

Issue involving when and Super Cricket sensors C thru F

There is a known issue regarding the use of the “when” command and sensors C through F on the Super Cricket. The issue also exists in using sensors on the Motor/Sensor Expansion Board.

Specifically, if the "when" trigger includes reading any of the sensors C through F, things get flaky and don't work.

This is indeed a bug. It has to do with a threading issue. The "when" command evaluates its condition between the execution of the main user Logo code, and sensors C through F are implemented as a multi-byte series of communications between the main PIC and slave PIC.

In order to fix this, this communication would have to move into the Cricket virtual machine (presently, it's implemented in a user-level Logo library).

So for now, the best approach is to not use sensors C through F inside the condition of the when.

Alternately, one might strategically enable and disable the when, making sure it's disabled before any sensor C - F activity in the main user thread.

(Last updated 2008-01-08)

The Beamer's yellow LED is continuously on.

If the Cricket Beamer's yellow “transmit” LED is continuously on, something is indeed wrong.

If you have a serial Beamer (not the USB model):

First, unplug the Cricket Beamer from the serial cable. If the yellow LED turns off, then the Interface Cricket itself is OK.

Next check the serial cable. Make sure you have a straight-thru cable and not a “null” (inverting) cable. Pin 2 on one end should go to pin 2 on the other end, 3 to 3, etc.

Use a terminal emulator (like HyperTerminal on Windows) to test your COM port. Put the settings to 9600 baud, N (no parity), 8 (data bits), 1 (stop bit), no hand-shaking. When you're connected to the Interface Cricket, type on your computer's keyboard. You should see your keystrokes echoed on your screen, and the Cricket Beamer's yellow LED should blink once for each keystroke.

If you can get this working, then your hardware is ready for Cricket Logo.

(Last updated 2010-05-05)