SD Loader
SD/Serial Loader
- Send/receive files to/from SD card from/to serial port
- Menu driven program
Features
- Supports SD cards up to 32GB
- FAT32 formatted
- Serial interface
- Full hardware Handshake support
Cards
- Constructed out of existing Land Boards cards
- QT Py board
- Either the SAMD board or RP2040 board versions
- QT Py Breakout board or QTPy49
- SD CARD X49
- MyMenu
- MCP23008 I2C interface
- OLED
- 5 Pushbuttons
- 3 LEDs
- Level Shifter mounted on GRID49 card
QT Py Breakout
SD CARD X49
MyMenu
Level Shifter (Optional)
- Use for "legacy" 5V Serial systems
- Not used for 3.3V systems
- Convert 3.3V QT Py Tx/Rx/RTS/CTS to "legacy" 5V
- 4-channel I2C-safe Bi-directional Logic Level Converter
Cabling
QT Pu to Level Translator Cabling
| NANO-BKOUT | SIGNAL | GRID49 | COLOR |
|---|---|---|---|
| D0 | RX (TO NANO) | G12 | BRN |
| D1 | TX (FROM NANO) | F12 | ORA |
| D2 | RTS FROM NANO) | E12 | YEL |
| D3 | CTS (TO NANO) | D12 | WHT |
| +5V | +5V | C12 | RED |
| GND | GND | H12 | BLK |
NANO-BKOUT to MyMenu Cabling
| NANO-BKOUT | SIGNAL | MyMenu | COLOR |
|---|---|---|---|
| H7-1 | GND | P2-1 | BLK |
| H7-2 | +5V | P2-2 | RED |
| H7-3 | SDA | P2-3 | WHT |
| H7-4 | SCL | P2-4 | BRN |
| H7-5 | INT(D6) | P2-5 | GRY |
NANO-BKOUT to SD_CARD_X49 Cabling
| NANO-BKOUT | SIGNAL | SD_CARD_X49 | COLOR |
|---|---|---|---|
| ISP-1 | D12 / MISO | J1-2 | BRN |
| ISP-2 | +5V | J1-8 | RED |
| ISP-3 | D13 / SCK | J1-3 | BLU |
| ISP-4 | D11 / MOSI | J1-4 | WHT |
| ISP-5 | RST* | N/C | OR |
| ISP-6 | GND | J1-1 | BLK |
| D9 | D9/ SDCS* | J1-5 | GRY |
Software
- Runs on Arduino Nano
Human Interface Design (HID)
- Menu driven
- OLED display
SD Card
- Library
- Example files
SD Card Library
- SD Card library
- The SD library allows for reading from and writing to SD cards, e.g. on the Arduino Ethernet Shield
- Based on sdfatlib
- The library supports FAT16 and FAT32 file systems on standard SD cards and SDHC cards
- It uses short 8.3 names for files
- The file names passed to the SD library functions can include paths separated by forward-slashes, /, e.g. “directory/filename.txt”
- Because the working directory is always the root of the SD card, a name refers to the same file whether or not it includes a leading slash (e.g. “/file.txt” is equivalent to “file.txt”)
- As of version 1.0, the library supports opening multiple files.
- The communication between the microcontroller and the SD card uses SPI, which takes place on digital pins 11, 12, and 13 (on most Arduino boards) or 50, 51, and 52 (Arduino Mega)
- Additionally, another pin must be used to select the SD card
- This can be the hardware SS pin - pin 10 (on most Arduino boards) or pin 53 (on the Mega) - or another pin specified in the call to SD.begin()
SD Card Example Code
- SD Card example Code
- Read and Write File example
- Read Card Information
- Read a file from a SD card using the SD library and send it over the serial port
- Create and destroy a file on a SD card
- List the files available in the directory of the SD card
SD Card Connections
** SCLK - CLK - pin 13 ** MISO - SDI - pin 12 ** MOSI - SDO - pin 11 ** SS - CS - depends on your SD card shield or module.
Serial
- Serial Reference
- Serial.begin(speed)
- Serial.available()
- Get the number of bytes (characters) available for reading from the serial port.
- This is data that’s already arrived and stored in the serial receive buffer (which holds 64 bytes).
- Turn off/on receive handshake based on Serial.available() count and storage
- Serial.write()
- Writes binary data to the serial port
- This data is sent as a byte or series of bytes
- To send the characters representing the digits of a number use the print() function instead.
- Syntax
Serial.write(val) Serial.write(str) Serial.write(buf, len)
