Teensy 2.0
This is the documentation for the port of NuttX to the PJRC Teensy++ 2.0 board. This board is developed by http://pjrc.com/teensy/. The Teensy++ 2.0 is based on an Atmel AT90USB1286 MCU.
Teensy++ 2.0 Features
Based on the 64-pin USB AVR Microcontroller AT90USB1286.
USB Full Speed (12Mbit/s)
USB Device Mode
120kbof available FLASH memory for programs.
8 kbytes SRAM and 4 kbytes of EEPROM
USB powered
16MHz crystal
48 General Purpose IO Pins
Pin Usage
AT90USB1286 TQFP64
PIN |
SIGNAL |
BOARD CONNECTION |
|---|---|---|
1 |
(INT.6/AIN.0) PE6 |
Pad E6 |
2 |
(INT.7/AIN.1/UVcon) PE7 |
Pad E7 |
3 |
UVcc |
(Voltage circutry) |
4 |
D- |
USB DP |
5 |
D+ |
USB DM |
6 |
UGnd |
GND |
7 |
UCap |
GND (via cap) |
8 |
VBus |
USB VBUS |
9 |
(IUID) PE3 |
N/C |
10 |
(SS/PCINT0) PB0 |
Pad B0 |
11 |
(PCINT1/SCLK) PB1 |
Pad B1 |
12 |
(PDI/PCINT2/MOSI) PB2 |
Pad B2 |
13 |
(PDO/PCINT3/MISO) PB3 |
Pad B3 |
14 |
(PCINT4/OC.2A) PB4 |
Pad B4 |
15 |
(PCINT5/OC.1A) PB5 |
Pad B5 |
16 |
(PCINT6/OC.1B) PB6 |
Pad B6 |
17 |
(PCINT7/OC.0A/OC.1C) PB7 |
Pad B7 |
18 |
(INT4/TOSC1) PE4 |
Pad E4 |
19 |
(INT.5/TOSC2) PE5 |
Pad E5 |
20 |
RESET |
Switch pulls to ground |
21 |
VCC |
VCC |
22 |
GND |
GND |
23 |
XTAL2 |
XTAL (16MHz) |
24 |
XTAL1 |
XTAL (16MHz) |
25 |
(OC0B/SCL/INT0) PD0 |
Pad D0 |
26 |
(OC2B/SDA/INT1) PD1 |
Pad D1 |
27 |
(RXD1/INT2) PD2 |
Pad D2 |
28 |
(TXD1/INT3) PD3 |
Pad D3 |
29 |
(ICP1) PD4 |
Pad D4 |
30 |
(XCK1) PD5 |
Pad D5 |
31 |
(T1) PD6 |
Pad D6, LED |
32 |
(T0) PD7 |
Pad D7 |
48 |
PA3 (AD3) |
Pad A3 |
47 |
PA4 (AD4) |
Pad A4 |
46 |
PA5 (AD5) |
Pad A5 |
45 |
PA6 (AD6) |
Pad A6 |
44 |
PA7 (AD7) |
Pad A7 |
43 |
PE2 (ALE/HWB) |
Pad ALE (Pulled down) |
42 |
PC7 (A15/IC.3/CLKO) |
Pad C7 |
41 |
PC6 (A14/OC.3A) |
Pad C6 |
40 |
PC5 (A13/OC.3B) |
Pad C5 |
39 |
PC4 (A12/OC.3C) |
Pad C4 |
38 |
PC3 (A11/T.3) |
Pad C3 |
37 |
PC2 (A10) |
Pad C2 |
36 |
PC1 (A9) |
Pad C1 |
35 |
PC0 (A8) |
Pad C0 |
34 |
PE1 (RD) |
Pad E1 |
33 |
PE0 (WR) |
Pad E0 |
64 |
AVCC |
VCC |
63 |
GND |
GND |
62 |
AREF |
Pad Ref (Capacitor to ground) |
61 |
PF0 (ADC0) |
Pad F0 |
60 |
PF1 (ADC1) |
Pad F1 |
59 |
PF2 (ADC2) |
Pad F2 |
58 |
PF3 (ADC3) |
Pad F3 |
57 |
PF4 (ADC4/TCK) |
Pad F4 |
56 |
PF5 (ADC5/TMS) |
Pad F5 |
55 |
PF6 (ADC6/TDO) |
Pad F6 |
54 |
PF7 (ADC7/TDI) |
Pad F7 |
53 |
GND |
GND |
52 |
VCC |
VCC |
51 |
PA0 (AD0) |
Pad A0 |
50 |
PA1 (AD1) |
Pad A1 |
49 |
PA2 (AD2) |
Pad A2 |
Halfkey Bootloader
Download the Teensy application from http://pjrc.com/teensy/loader.html. Instructions are available for your OS at that place as well.
Summary:
Start Teensy
Press button on the Teensy board
Select a HEX file (File menu)
Select “program” (Operations menu)
Reboot (Operations menu).
Serial Console
A serial console is supported on an external MAX232/MAX3232 Connected on PD2 and PD3:
Port D, Bit 2: RXD1, Receive Data (Data input pin for the USART1).
When the USART1 receiver is enabled this pin is configured as an input regardless of the value of DDD2. When the USART forces this pin to be an input, the pull-up can still be controlled by the PORTD2 bit.
Port D, Bit 3: TXD1, Transmit Data (Data output pin for the USART1).
When the USART1 Transmitter is enabled, this pin is configured as an output regardless of the value of DDD3.
AT90USB90128/64 TQFP64
PIN |
SIGNAL |
BOARD CONNECTION |
|---|---|---|
27 |
(RXD1/INT2) PD2 |
Pad D2 |
28 |
(TXD1/INT3) PD3 |
Pad D3 |
Plus power and ground. There are numerous ground points and both USB 5V and Vcc are available.
SD Connection
I have the SD-ADP SD/MMC Card Adaptor from www.gravitech.com (http://www.gravitech.us/sdcaad.html). Features:
On-board 3.3V regulator
Connect directly to 3.3V or 5.0V microcontroller
Card detect LED
Includes 11-pin male header
Board dimension: 2.0”x1.3”
SD-ADP Pinout / SD Connection
J2 |
NAME |
SD CARD |
DESCRIPTION |
|---|---|---|---|
1 |
VIN |
(regulator) |
Input power to the SD card (3.3V to 6.0V) |
2 |
GND |
3,6,12,13 |
Common (Connects to the housing of the SD socket) |
3 |
3V3 |
4 3.3V |
Output voltage from the on-board 3.3V regulator (250mA) |
4 |
NC |
9 NC |
Connect to pin 9 on the SD card (not used in SPI mode) |
5 |
CS |
1 DAT3/CS |
Chip select (1*) |
6 |
DI |
2 CMD/DI |
Serial input data (1*) |
7 |
SCK |
5 SCK |
Serial clock (1*) |
8 |
DO |
7 DAT0/DO |
Serial output data |
9 |
IRQ |
8 DAT1/IRQ |
Interrupt request, connect to pin 8 on the SD card (not used in SPI mode) |
10 |
CD |
10 CD |
Card detect (active low) |
11 |
WP |
11 WP |
Write protect |
(1*) Via a 74LCX245 level translator / buff
Teensy SPI Connection
J2 |
NAME |
PIN |
NAME |
PAD |
|---|---|---|---|---|
1 |
VIN |
– |
Connected to USB +5V |
|
2 |
GND |
– |
Connected to USB GND |
|
3 |
3V3 |
– |
Not used |
— |
4 |
NC |
– |
Not used |
|
5 |
CS |
10 |
(SS/PCINT0) PB0 |
Pad B0 |
6 |
DI |
12 |
(PDI/PCINT2/MOSI) PB2 |
Pad B2 |
7 |
SCK |
11 |
(PCINT1/SCLK) PB1 |
Pad B1 |
8 |
DO |
13 |
(PDO/PCINT3/MISO) PB3 |
Pad B3 |
9 |
IRQ |
– |
Not used |
— |
10 |
CD |
14 |
(PCINT4/OC.2A) PB4 |
Pad B4 |
11 |
WP |
15 |
(PCINT5/OC.1A) PB5 |
Pad B5 |
Toolchains
Read about the tool chains at Microchip AT90USB.
Teensy++ Configuration Options
Individual subsystems can be enabled:
CONFIG_AVR_INT0=nCONFIG_AVR_INT1=nCONFIG_AVR_INT2=nCONFIG_AVR_INT3=nCONFIG_AVR_INT4=nCONFIG_AVR_INT5=nCONFIG_AVR_INT6=nCONFIG_AVR_INT7=nCONFIG_AVR_USBHOST=nCONFIG_AVR_USBDEV=nCONFIG_AVR_WDT=nCONFIG_AVR_TIMER0=nCONFIG_AVR_TIMER1=nCONFIG_AVR_TIMER2=nCONFIG_AVR_TIMER3=nCONFIG_AVR_SPI=nCONFIG_AVR_USART1=yCONFIG_AVR_ANACOMP=nCONFIG_AVR_ADC=nCONFIG_AVR_TWI=n
If the watchdog is enabled, this specifies the initial timeout. Default is maximum supported value.
CONFIG_WDTO_15MSCONFIG_WDTO_30MSCONFIG_WDTO_60MSCONFIG_WDTO_120MSCONFIG_WDTO_1250MSCONFIG_WDTO_500MSCONFIG_WDTO_1SCONFIG_WDTO_2SCONFIG_WDTO_4SCONFIG_WDTO_8S
AT90USB specific device driver settings:
CONFIG_USARTn_SERIAL_CONSOLE: selects the USARTn for the console and ttys0 (default is no serial console).CONFIG_USARTn_RXBUFSIZE: Characters are buffered as received. This specific the size of the receive bufferCONFIG_USARTn_TXBUFSIZE: Characters are buffered before being sent. This specific the size of the transmit bufferCONFIG_USARTn_BAUD: The configure BAUD of the USART.CONFIG_USARTn_BITS: The number of bits. Must be either 7 or 8.CONFIG_USARTn_PARTIY: 0=no parity, 1=odd parity, 2=even parityCONFIG_USARTn_2STOP: Two stop bits
AT90USB specific USB device configuration:
CONFIG_USB_DISABLE_PADREGULATORCONFIG_USB_LOWSPEEDCONFIG_USB_NOISYVBUS
Configurations
Each Teensy++ configuration is maintained in a sub-directory and can be selected as follow:
$ tools/configure.sh teensy-2.0:<subdir>
Where
<subdir>is one of the configuration sub-directories described in the following paragraph.Note
You must also copy avr-libc header files, perhaps like:
$ cp -a /cygdrive/c/WinAVR/include/avr include/.
These configurations use the mconf-based configuration tool. To change a configurations using that tool, you should:
Build and install the kconfig-mconf tool. See
nuttx/README.txtsee additionalREADME.txtfiles in the NuttX tools repository.Execute
make menuconfiginnuttx/in order to start the reconfiguration process.
By default, all configurations assume the NuttX Buildroot toolchain under Cygwin with Windows. This is easily reconfigured:
CONFIG_HOST_WINDOWS=yCONFIG_WINDOWS_CYGWIN=yCONFIG_AVR_BUILDROOT_TOOLCHAIN=y
Build with GCC disables CONFIG_DEBUG_OPT_UNUSED_SECTIONS by default. This is because the linker script was not checked to determine if it properly prevents removal of sections which the linker considers unreferenced but which must be present in the binary.
hello
The simple apps/examples/hello “Hello, World!” example.
nsh
This is a reduce NuttShell (NSH) configuration using apps/example/nsh. The
serial console is provided on USART1 and can be accessed via an external RS-232
driver as described above under “Serial Console”.
ostest
This configuration directory, performs a simple OS test using
apps/examples/ostest.
Warning
The OS test is quite large. In order to get it to fit within AVR memory constraints, it will probably be necessary to disable some OS features.
usbmsc
This configuration directory exercises the USB mass storage class driver at apps/system/usbmsc. See apps/examples/README.txt for more information.
Warning
THIS CONFIGURATION HAS NOT YET BEEN DEBUGGED AND DOES NOT WORK!!! ISSUES:
THE SPI DRIVER IS UNTESTED
THE USB DRIVER IS UNTESTED
THE RAM USAGE MIGHT BE EXCESSIVE
Update 7/11: (1) The SPI/SD driver has been verified, however, (2) I believe that the current teensy-2.0/usbmsc configuration uses too much SRAM for the system to behave sanely. A lower memory footprint version of the mass storage driver will be required before this can be debugged.