Carrier board

OpenReset Project

This project is designed to allow you to easily reset your card with a standalone device. No need to connect to a computer to use (in fact you can't read the card from a computer using this device).

Supported cards:

• Vital Bracelet Dim
• Vital Bracelet Memory (VBM)
• TamaSma Card
• PreData Memory (for Heart Cure Watch, unreleased as of writing)

DIY hardware

It is easy to build your own OpenReset from loose parts.

Bill of materials

To build your own OpenReset, you will need the following:

• 1x Raspberry Pi Pico
• 1x microSD card breakout board (suggested model TBD)
• 1x Red LED
• 1x Resistor (for current limiting the LED; please calculate the value based on your LED's datasheet, but in general a 330Ω resistor will work)
• 1x Toggle switch or button if your breakout board does not have card detect broken out
• 1x Breadboard (optional)
• Hookup wires

Hardware connection

1. Connect the 3V3 pin on the Pico to your positive power rail and any GND pin to your ground rail.
2. Connect the microSD card breakout to the Pico as follows:
   • Pico pin 21 to DAT0 or MISO
   • Pico pin 22 to DAT3 or CS
   • Pico pin 24 to CLK or CLK
   • Pico pin 25 to CMD or MOSI
   • Pico pin 26 to card detect. Note, if your breakout board does not have a card detect pin, you can connect a toggle switch or button to pin 26, and connect the other side to ground.
3. Connect the red LED such that the anode end has the Pico's pin 6 upstream. Connect a resistor before or after the LED, and connect the loose end of the LED or resistor to ground.

Carrier board

Alternatively, you can have a carrier board fabbed and solder the Pi Pico to it along with a few other components.

Board design files are in the carrier_board directory. Gerbers are available in the carrier_board/gerber directory, and are available as a ZIP file.

Bill of materials

• 1x Raspberry Pi Pico (U1) (Official resellers)
• 1x Molex 0475710001 push-pull microSD card connector (J1) (Digikey)
• 1x 0603 Red LED (D1)
• 1x 0603 Resistor (R1) (for current limiting the LED; please calculate the value based on your LED's datasheet, but in general a 330Ω resistor will work)

Software setup

1. Install MicroPython on to your Pi Pico
   • Download a recent build from here
   • Hold the BOOTSEL button on your Pico, then plug the Pico into your computer while still holding the button. You can release the button once the Pico shows up on your computer as a USB drive.
   • Drag the .uf2 firmware you have downloaded to the USB drive, and the Pico will install the firmware and reboot
2. Upload the code in the firmware directory to the Pico
   • I use Thonny. After you install it, open it up and click the button at the bottom right of the screen. Select MicroPython (Raspberry Pi Pico).
   • Open up each file in the firmware directory, and select File -> Save copy... from the menu strip. Click Raspbery Pi Pico when asked where to save to. Type in the name of the file in the File name box, and click OK.
3. Replug the Pico and verify the code is installed
   • The red LED should be lit

Usage

The board is easy to use. All you have to do is insert your card and the device will automatically perform the erase. The red LED will always be on to indicate power, and the green LED on the Pi Pico will light up when the erase is in progress. After the erase is completed, the green LED will extinguish. If there is an error, the red LED will blink off a number of times to indicate the error.

• 1 time: wrong card type, check you are using the correct card
• 2 times: wrong flash chip; if you are sure your card is genuine, file an issue in this repo
• 3 times: card is not responding as expected

There are messages printed to UART if you need more info on troubleshooting. I suggest loading the code up in Thonny and checking the shell for the messages.

Warning: TamaSma Card locking area is embedded in the card header. By nature of SPI NOR flash, changing this data will involve erasing the sector, so there is a risk of breaking the data if the connection is bad. Therefore, be careful when plugging in a TamaSma Card to plug it in firmly.

If your are using a DIY build and your microSD breakout board does not have a card detect pin, then you can use the switch/button alternative. Flip the switch or hold the button after you have inserted a card. The process will complete and the red LED will flash if there are errors. If you are using a button, make sure to hold the button until the error has finished blinking, if applicable. Flip the switch again or release the button before inserting the next card.