PiPicoMite01 Rev 1 Connectors
Contents
Connectors
- PiPicoMite01 Rev 1 connectors are in a different order than later PiPicoMite01 revs
J1 - MCP23017 - I2C Interrupt
- Useful for interrupt driven input (no polling)
- Install jumper to connect INTA interrupt from MCP23008 to GP0 on Pico (GP2 on later rev cards)
- No Pull-up
J2 - USB B Power Connector
- Full size USB B connector
- No USB signal connections, just used for power
- J4 provide an alternate way of powering the card
J3,J5 Pico Connectors
Pico Function Mapping
| GP | FUNCTION | PICO PIN | GP | FUNCTION | PICO PIN | |
|---|---|---|---|---|---|---|
| GP0 | I2C1_INT (MCP23017) | 1 | GP16 | VGA_HSYNC | 21 | |
| GND | AUDIO-GND | 8 | GP17 | VGA_VSYNC | 22 | |
| GP6 | AUDIO-L | 9 | GP18 | VGA_BLU | 24 | |
| GP7 | AUDIO-R | 10 | GP19 | VGA_GRN_LO | 25 | |
| GP8 | PS2_CLK | 11 | GP20 | VGA_GRN_HI | 26 | |
| GP9 | PS2_DATA | 12 | GP21 | VGA_RED | 27 | |
| GP10 | SD_SCK | 14 | VSYS | PS2_5V | 39 | |
| GP11 | SD_MOSI | 15 | 3.3V | PS2_3.3V | ||
| GP12 | SD_MISO | 16 | 3.3V | SD_3.3V | ||
| GP13 | SD_SLVSEL | 17 | ||||
| GP14 | I2C1_SDA (MCP23017) | 19 | ||||
| GP15 | I2C1_SCL (MCP23017) | 20 |
J4 - 5V Input
- Useful for external 5V
- J2 is an alternate way of powering the card
J6 - 3.3V Power Out
- Useful for connecting up 3.3V power to external interfaces
J7 - Audio
- Low Pass filter
- Voltage divider to get to line level
- Two Tone Test
- Play a WAV file
OPTION AUDIO GP6, GP7 PLAY WAV "file.wav" PLAY STOP
J8 - PS/2 Keyboard
The PS2 keyboard connects to the Raspberry Pi Pico via a level shifter and works as a normal keyboard with the function keys and arrow keys fully operational. It can be configured for the standard US layout used in the USA, Australia and New Zealand or specialised layouts used in the United Kingdom, Germany, France and Spain.
J9 - GPIO
- 2x10 Header
- Later revs change the pinout to move the 3.3V power to the end
- MCP23017 I2C Port Expander
- 16 bits of programmable I/O
Initialization Code
SetPin GP14, GP15, I2C2 I2C2 OPEN 400, 100 I2C2 WRITE &H20, 0, 2, &H00, &H00 I2C2 WRITE &H20, 0, 2, &H01, &H00
J10 - VGA
The VGA output is 640 x 480 pixels in monochrome mode or 320 x 240 pixels in colour mode with 16 colours (1 bit for red, 2 bits for green and 1 bit for blue). The VGA output is generated using the second CPU on the RP2040 processor plus one PIO channel so it does not affect the BASIC interpreter which runs at full speed on the first CPU. A handfull of components (resistors and a couple of diodes) is all that is required to connect the VGA monitor.
From within your BASIC program you can turn pixels on/off and draw lines, boxes and circles in any colour. Text can be positioned anywhere on the screen and displayed in any colour in a variety of fonts.
The built-in editor within MMBasic works perfectly with the VGA monitor and PS2 keyboard to allow programs to be edited (with colour coded text) and saved to an SD card.
H1 - I2C2 Terminators
- Install shunts to terminate SDA, SCL signals
- Commands
SETPIN GP14, GP15, I2C2 I2C2 OPEN 400, 100 I2C2 WRITE &H20, OC, LEN, B0[, B1...] I2C2 READ &H20, OX, LEN, BUFF()
- &H20 - I2C Address 0x20
- OC: 0=terminate after, 1=chain next
- len - Length of buffer (normally 1 for receive)
- B0,B1... Bytes to send
- BUFF() - receive buffer
SD1 - SD Card
The PicoMiteVGA firmware reserves eight program storage "slots" in the Raspberry Pi Pico flash memory. Programs can be saved and retreived from these without the need for any additional storage.
For more storage SD cards can be connected with full support for these built into MMBasic including the ability to open files for reading, writing or random access and loading and saving programs. SD cards connect directly to the Raspberry Pi Pico and the firmware will work with cards up to 32GB formatted in FAT16 or FAT32. The files created can be read and written on personal computers running Windows, Linux or the Mac operating system.
OPTION SDCARD GP13, GP10, GP11, GP12
