Nintendo DS Hardware Exposed

Introduction

This page is dedicated to showing and explaining the internal electronic workings of the Nintendo DS games console as well as its accessories and games.

Introduction

Accessories

My Health Coach: Manage Your Weight Pedometer

You can email me at james.boshikoopa@gmail.com

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Accessories

My Health Coach: Manage Your Weight Pedometer

I did not buy My Health Coach: Manage Your Weight by Ubisoft for the DS because of the software but for the included pedometer which, together with the 'game', only set me back 50p. The pedometer is a lot larger than the standalone ones you can buy and has 'Thrustmaster' branding as well as being labelled as a ‘Ubisoft Pedometer’ and is intended to be worn so that it can record the user's steps. To transfer your activity to the game the pedometer is to be plugged into the GBA slot of a DS/DS Lite (not DSi which lacks a GBA port). This is not the first DS game to take advantage of the GBA slot of a DS as Guitar Hero: On Tour series used the GBA port for the Guitar Grip.

The pedometer (see below) uses a CR2032 battery to store the count of steps that have been detected; the battery can be replaced by removing the battery holder from the side by pressing the tab inward while pushing away from underneath.

There is a reset button on the top to reset the step count and an LCD (see below) on one end to show the recorded steps. You can tell that the pedometer uses a simple mechanism to detect steps as you can shake the pedometer to get 1 or 2 steps increase.

Four screws keep the pedometer together; one is hidden under the belt clip but to get to that screw you must first remove the belt clip which is done by pressing the small plastic catch under the belt clip with a flat head screwdriver while pushing down on the belt clip toward the GBA slot end. If you need to fix the belt clip back in just put the belt clip back into the holes and press up toward the LCD end of the pedometer.

As you can see below there is a surprising amount of circuitry considering how simple the pedometer is in operation although it does have to communicate with the DS's GBA port so that adds to the complexity.

The main board includes the GBA contacts (bottom of the photo above), the battery holder (labelled as ‘BAT1’), and the reset switch (marked as ‘RESET_COUNT1’). The LCD attaches to the main board via a flat cable and the step sensor is connected to the main board with 2 wires (top left below the LCD in the photo above; the step sensor is hidden under the main board). Also written on the main board is a date of 2007 (the game is from 2008), ‘E252800’, ‘THRUSTMASTER’, and ‘OKE’. There are numerous test points on the main board and what looks like provision for a 7-way connector J2 (at the left in photo above) that has not been populated, possibly for programming/debugging.

All the components are on one side of the main board and the chips are:

M430V187 (U3) Unknown, possibly a microcontroller.

74HC75 (U1) Quad bistable transparent latch.

74HC00 (U4) Quad 2-input NAND gate.

75HC125 (U2) Quad buffer/line driver.